That's why bicycles have chains and not gears ;) they are much more efficient, have much less wear and takes a lot less maintenance than gears. It's no just a matter of noise. Let's all just take a second and thank the guy that invented the chain.
@flymali691 ...what are you thinking bicycle chains are typically attached to? Upon a second glance, the noise here seems to be coming from the chain making poor contact with the front gear just due to the lack of chain slack. He could have gotten rid of his weird excuse for a chain tensioner, since it's a single gear ratio, then just actually tensioned the chain directly. But given everything I've seen, I don't think this guy has a working relationship with bicycles
@@tay-lore A gear is specifically something that interlocks with other gears whereas a sprocket is specifically designed to work with chains. Sprockets and chains go together.
@@TheInfectoususually* interlocks with other gears. Also that’s for English. In my language both things are just called teeth wheels directly translated
Ya so basically if you were going down a hill you would normally use breaks on, you can recover some of that energy into the fly wheel. But if you would not normally use breaks to go down the hill you would be better to just let your inertia handle it. Less steps less loss The most practical application for that sort of system would be something where there is an overall drop in elevation with steep hills down where you have some reason that you cant just let your speed go up and down as you pass over the hills that youd likely already clear with the overall downward slope
@@squirrelspown My city has a ton of relatively steep hills with regulated crossings at the bottom, so the use case is very real sometimes. If only the implementation wasn't mediocre at best with a flywheel
@@nonnodacciaio704 If you'd have to use your brakes to slow yourself down under normal circumstances, yes it does. Not having an infinitely variable gear doesn't help but it should still work. Clearly it won't get you all (or probably very far of) the way up the hill, it will get some of the way up for free.
@@MrCh0o Ya that makes sense but....like he described in the video though, one might infer that the best case scenario is if you never come to a full stop. At best reducing speed by up to half before you lose your storage. so if you need to stop at cross walks you may loose alot of the theoretical benefit by dumping a bunch of energy into breaks So im just spit balling here....let me know what you think I imagine the optimal workflow would be leaving it engaged and peddeling with assistance the whole way so all you need to do is overcome friction losses and any positive delta and the flywheel sort of governs your speed sort of just acting for you as if you had the inertia of a large object even though you are a small one.....but you dont get the potential energy benifits of being a large object Does anyone know how the math works out on that? if speeding up and slowing down is required i imagine you would peddle hard on the way down to charge it diss engage completely while you look if you need to slow down or do slow down.... try to get back up to a solid portion of the disengagement speed and use it to push up maybe 1/3 of the hill?
There's a HUGE problem with flywheels, as a large mass rotating at high speed introduces unpredictable changes in behavior of the entire system, when turning left or right.
Seem like you'd have to practically stop to make anything more than a slight turn. I would think that the energy to turn the flywheel has to come from somewhere, too, which means more effort for the rider. But I am totally out of my element with physics so I could be completely wrong on that. Would be interesting to see how it compares to riding an actual bike with some of the physics explained.
@@tastybluecrayon the drive train (engine, gearbox, etc) on a motorcycle is like a big flywheel in the middle of the bike, and when you're maneuvering with the engine fully engaged to the wheel vs the clutch pulled in and the engine idling there is a noticeable difference in how it handles. I don't think that turning on this bicycle would be as hard as you're saying, but it would feel heavier to lean left or right.
@@MortimerJones99 Its harder to turn due to the gyroscopic forces of the wheels, not due to the engine. The flywheel is between the engine and the clutch, clutching in and out only disconnects the gearbox and front sprocket, way less gyroscopic force than even the crankshaft itself. You could however solve this problem with bicycles by having two flywheels, one on the front axle and one on the rear. Will feel weird when stopped or going slow, but shouldnt impair turning, in fact i think it would apmlify it
@@SportSoulLife He means when your driving, with the engine up at its running RPM vs having the clutch disengaged and the engine idling all while rolling along at the same speed. Your bike is moving at the same speed, but the engine isn't turning anywhere near as fast. Thus less gyroscopic stabilization.
You need a 19lbs plate and a transmission to a higher gear ratio to get more value out of the discharge. You'll see a dramatic change in how aggressive the takeoff will be. A sort of tapping of the clutch can get you up to a pretty high speed. I'd recommend doing the transmission from the other side of the bike. A sort of 2chainz bike if you will.
My preference is the Spec Clutch. Only cause Mitsubishi Evo. :) You could change the Clutch to a better one. I'd also recommend Volk Racing Rims for bikes like yours :D. I've also heard Corbeau makes really awesome bike seats!
@@thelakeman5207 I agree. I build high speed gearboxes for a living, not only will it turn with far less effort, the teeth will last 1000x longer. A wet gearbox is a happy gearbox.
No one said you'd be using just the flywheel. Gentle effort plus mechanical assistance means you're flying up that hill, same as E bike. @@squidwardo7074
Tom, you need 2 gears for the fly-wheel, a high gear-ratio for slowing down and a low-gear-ratio for speeding up, think of this this way when equilibrium is reached you want fly wheel speed high relative to wheel speed, but when speeding up you want the wheel speed to be high relative to fly wheel, anything inbetween can "solved" with your clutch.
This is what I was thinking with 2 clutches... But probably has diminishing returns as the larger mismatch of speed across the clutch means more lost energy as heat.
@@JamesUKE92 I agree, 2 clutches with their own gearsets. Braking force will be much higher than acceleration force, but that's exactly what you want. You'll have a small assist accelerating up to a much higher speed.
The problem is not a lack of torque, it's a mismatch between the speed of the bike and the flywheel. All the time the clutch is slipping, it is wasting energy. But as soon as it engages, it is no longer transferring power because the speeds match. As he says a couple of times, he needs a continuously variable transmission so the flywheel can accelerate as the bike decelerates.
Maybe CVT actuated by hydraulic brake levers may be solution. That would give variable ratio gearing. Also clutch mechanism functionality could be achieved by undertensioning belt between CVT wheels.
@@vyrukas2 The simplest solution and probably the most energy efficient on small scale is to use an electric generator and motor (or ofc ditch the flywheel and use ultracaps or high amperage batteries).
Needs a sprag clutch on the flywheel in series with the clutch, so that when decelerating it automatically disengages when the flywheel exceeds the bikes speed.
There's a slight issue with that. You would go from decelerating at a fair rate to instantly freewheeling. I was thinking the same thing but I reckon it would be a bit hairy having that occur.
A centrifugal clutch linked to a centrifugal variator is kinda what is needed. Someone posted some info in a comment about a super simple ball CVT by “funtastyx” that could possibly be integrated somehow. With a 3D printer and a NC router there's a lot that could be done. I also reckon a car flywheel would be a better option as well as more of it's weight is further from it's axis which make it a more efficient use of the weight.
@@Alan_Hans__ it would an already is a deminishing braking effect, as the speeds begin to match it brakes less and less, wouldnt go from all to nothing itd be gradual.. the issue with the sprag clutch is youd need a way to put the energy back to the ground, either a whole seperate clutch and lever or some way to take the sprag out of the system for acceleration.. i think itd be a fine system if the flywheel weight alot more, with it weighing less than the bike the speeds match each other far to quickly and theres not much energy in the flywheel to accelerate you, and if you dont use the energy after a stop it doesnt have much braking effort left for the next stop either, with a heavier fly wheel and a higher gear ratio for it to spin it far faster than 2300rpms.. like 10k-15k rpms youd be able to store multiple stops, long descents down hills where it isnt safe to just build max speed you need to brake.. might be able to store enough energy in it to actually propel you to cruising speed or assist meaninfully in hills at that point
Tip for the flywheel: Because the mass at the outside of the flywheel has more rotational inertia you would have better performance using a thin central disk, and welding or bolting thick rings on both sides to make the cross section an I beam. For the same volume/mass you would have a much higher rotational energy saved up at the same RPM. :)
@@ghlibisk67 sure it would keep it safe for the rest of your life.... which happens to be about 3 minutes longer than it takes for the glue to fail launching the razor into your femoral artery.
IT willl not work. Try to hold bicycle by the hotizontal axis , put it in Rotation and try to tilt it. You will feel a strong force that tries to move the axis in a vertical position. The Same will happen with the flywheel when you change the direction in a bend. And why all this effort? We already have the E-Bike and we can use Rekuperation like an a car
I think a viable use-case for a flywheel is on a trike. You pedal at a constant speed more or less, not exhaustingly hard (< 200W), including while stopped. Then you have hopefully cached up enough energy while sitting at traffic lights to have decent accelleration without needing a lot of Li batteries that are too expensive for their service life. A flywheel applied this way should last forever. Probably there is a known name for this concept.
@@JustKhariI would. I used to commute, train, and race from 1986-2012. In 2001, I had my neck broken in 3 places, C3, C5, & C6. My neck is fused from C3-C7 (entire visible part of your neck). For me, what would be a normal fall for you, could be potentially disastrous for me, quite possibly the next break would be at C2-C3, or C7-T1. Best case scenario for C2-C3 is quadriplegic, but more likely killed. C7-T1, best case paralyzed from the waist up, but most likely quadriplegic. So, if I want to ride again (and I miss it terribly) my only option is a trike. That’s who tf, would ride a trike.
@@JustKhari literally anyone who uses a trike and has to cross intersections, what else do you want them to do? blow through the intersection while cars are crossing?
@@JustKharijesus christ what do you think a traffic light is for? I cant think of a single vehicle(including a bicycle) which is exempt from traffic stops. you must be from the bayou.
Now you need to design a CVT to transfer more more energy into the flywheel instead of wasting the remainder of the momentum in brake pad heat. Also, with a different spoke design you might be able to place a 26" flywheel concentric in the wheel. The larger size could store more energy at lower rotational speed.
@@lIIIIIllll Do you know how CVTs work? It wouldn't eliminate the need for a lever. You'd still need to manually operate a clutch to engage the system. What a CVT would do is massively increase the efficiency of the system. Tom made a little diagram showing how the flywheel and the bicycle wheel eventually reach the same speed, but with a CVT it would allow for the flywheel to reach speeds faster than the bicycle wheel.
@@lIIIIIllll I'm going to be very straightforward here and try to be as not mean as I can. Your comment is quite literally the dumbest take possible on the use of a CVT in this scenario. The use of a clutch lever in this situation wouldn't be to actuate the transition of the CVT from lower gear ratios to higher gear ratios. The use of a clutch lever in this situation would be to engage the entire system. The KERS shouldn't be functioning at all times; it should only be functioning during stopping and starting, so you use a lever to engage the system when you're stopping and starting. Then if the CVT functions properly, you couldn't just use a CVT system from a scooter or car you'd have to design one for this specific use case, it would incredibly increase the efficiency of storing energy into the KERS and retrieving energy from the KERS.
@@lIIIIIllll I'm going to reply here then stop because at this point I think you're intentionally being obtuse. First, I never discussed anything near physics; I described the very simple mechanical reality of a single gear being less efficient than a CVT in regards to energy transfer from one rotating object to another. Second, I didn't even push the idea that Tom should design and build a CVT. I pointed out that a hypothetical CVT would still need a lever for engaging the KERS. Third, this hypothetical CVT wouldn't even be that complicated to build. You could almost entirely use scooter CVT design; you'd just have to tune the centrifugal spring mechanism to operate at bicycle speeds instead of scooter speeds. Finally, Tom literally build his own electric motor for a video. Would it really be that surprising if someone who enjoys building e-bikes and e-bike related things built a CVT for a KERS?
@@lIIIIIllll I genuinely thought I wouldn't respond to you again, and I've made a promise to myself to not respond again no matter how stupid your response, so this will absolutely be the last bit I type here: 1. You don't understand chronologically linear steps. (See your step 6) 2. The lever in question is to engage the KERS and start spinning the flywheel, I don't even understand what you think I'm talking about. Are you trying to imply that I'm referring to the internal clutch in the output? 3. KERS stands for Kinetic Energy Recovery System. Yes we are talking about a KERS even if it is purely mechanical and not electronic. 4. Your worry about slippage is genuinely stupid because we're working with a damn human as the load. Less load means less torque necessary. Less torque necessary means less friction needed on the CVT to prevent slippage. 5. The tuning would be to make the CVT work at bicycle speeds not "human size." 6. Your point 9 is accurate, but once again I wasn't the one who was suggesting actually building a CVT. I was pointing out the logistics of operation and hypothetical efficiency. 7. I'm now absolutely certain you're being intentionally obtuse because you've misquoted me, responded to points not made, arbitrarily tried to alter the definition of a term being used, and ascribed motive that wasn't there. If you're a troll, congratulations you got me. If you're not a troll you might want to pick up that mic and use it to ask someone to teach you how to read again because you have clearly not read the comments you've responded to.
Why not use a circular spring to store rotational energy while braking, so you can store the energy for a large amount of time without the flywheel slowing down? That'll come with the added advantage that you're not adding as much mass to the bike, you only need engage the mechanism while braking, and it won't be as noisy.
Thats called elastic energy and is much more limited in the amount of energy that you can 'store' in the spring. Compared to a flywheel. Its all old idea's in a new jacket. Has been done centuries ago. Not very effective.
I found myself nodding in understanding multiple times through this video lmao you're so good at explaining these things without having to dumb down the concepts
It reminds me of when I rode a Yamaha Virago motorcycle which had a mono-shock rear suspension. The one shock absorber was positioned oriented horizontally front to back under the seat. And it was filled with nitrogen at a pressure of 150 to 200 psi.
I'm actually curious as to how effective the flywheel could be in maintaining the speed while coasting rather than using the energy to take off from a start. Just a thought.
So whatever momentum stored in the flywheel, is taken from the momentum that would've been stored in the bike. But if its propelling the bike, the bike will coast almost as far as it did without the flywheel. A little less due to all the friction.
In order to get the energy into the flywheel it uses the momentum of the bike, so it causes the bike to slow down but the flywheel spins up to top speeds. It means any amount of momentum you use to spin up the flywheel slows the bike, so the only way to benefit from this is to use it for a brake, for only when you have to slow down or stop anyway. Otherwise if you tried to use it to coast you would first have to pedal up to speed, then engage the flywheel in order to get it spinning, but this will slow you down anyway, and all you would be accomplishing is going faster, then braking, then going faster, then braking, etc... It would be a waste of use, because you could just avoid it all and just keep pedaling and you will get their faster, and with less energy. The only way to use it to actually benefit, is the way the guy in the video plans to use it, as a brake. Hey, be happy, this is a awesome regen braking apparatus, all mechanical no electrochemical batteries..
@@TheRebelmanone the efficiency is comparable too! And he's just one man with not very precise equipment (according to him). I imagine it can be much more efficient (% wise, not compared to ebike) if it's industrialized
I can already imagine V2 of this bike: Tom pedaling next to you at a red light. You look at him weird. Then green light > clutch engage > zoom away. You in dust.
I think the bike would work great on hills. You can store all the excess energy from riding downhill into the flywheel. Imagine Toms smirky grin at the red light on the foot of a hill. Then he goes rattle rattle SWOOSH. Until he has to carry the extra 6kg back up the hill by muscle.
Honestly this one seems weird. Cool idea, but acceleration is already the one thing bikes excel at. Any cyclist who uses their gears well can smoke cars at an intersection. Wind and hills are the primary enemies of a bike.
Cool concept! What if you used a torsion spring instead of a flywheel? Might be lighter, plus there would be no time limit on stored energy. Could add some kind of ratcheting mechanism so that it can’t propel the bike backwards while tensioning the spring, and then probably another handle would be needed to engage some kind of reversing gear and release the spring tension 🤷♀️
@@Deontjie Other than it being a project to further one's skills and understanding. I liked what he did in the middle, ignoring the braking part and just seeing whether the flywheel at maximum speed could even accelerate him much.
I had an idea like that before, but have never been disciplined enough to invent things. My main idea was for the gyroscopy to help with balance at red lights, but releasing the power for a head start is pretty clever too.
I think I would LOVE this arrangement on particularly hilly rides. I'd use gravity on the downhills to spin-up the flywheel then release that energy for a boost at the base of the hill and the start of the next climb.
*Yeah. It will be a real pleasure lugging that heavy flywheel up the hill. it weighs more than an bike-sized lithium storage battery. I'll go for the battery, thanks.*
A bolt on kit could probably be made or combined with an existing engine based design to help improve efficiency. It is quite impressive that you've managed this with simple machining tolerances limiting you. You should try a design with the flywheel weighted towards its edges (i.e. thicker towards the edge or with a heavier metal bracketed around the circumference of the flywheel!
Unless there is some reason to brake, though, a flywheel system would be pretty much useless for retaining energy from hills. You *already* retain energy from hills as it is converted to KE at the bottom. The big difference between having a flywheel or not in the case of simply going down a hill and back up is what your max velocity at the bottom would be. This may save you some losses from aero drag, but the flywheel itself would add all sorts of mechanical drag in its own right. Just listen to the hellish clacking and screeching that Tom's rig produces, even when the clutch *isn't* engaged. All that is energy being lost from the bike. Not to mention the danger of a high-speed flywheel mounted on a bike and all the stress that would be experienced by the mounting and bearings due to gyroscopic precession in turns. The implementation of a flywheel system like this would only be useful for helping to retain substantial losses of energy, such as when braking or from aero at high speeds. In other words, what it's good for: Going down a hill, stopping, then going up a hill. Reducing max speed on large hills to save from aero drag. Bikes that are designed for slower speeds. Straight lines. What it is not good for: Your average ride across mild slopes. Any instance where you want to achieve high speeds. Bike designs that are already built for low aero drag. Sharp turns.
@@christopherbare9277 The flywheel will allow you to slow for junctions and corners at the bottom of the hill, but it is more efficient to store kinetic energy as your speed rather than the flywheel rotation.
@@hesterclapp9717 nope, more like only a quarter. Compare the graph: flighwheel meets bike speed halfway during breaking. And during acceleration bike meets flighwheel speed half way again. Without a clever gearbox this won't work out
When he began to say "because steel", there was a small stop, so I was honestly expecting for second for the sentence to continue with "because steel is heavier that feathers"
@@420frankp yeah okay 11k rpm in what stock car? an rx-7/8 with rotary only redlines at like 9-10k. Also a flywheel is much more dangerous than an engine, the entirety of energy stored is stored as kinetic energy. An engine has al little rotating mass as possible, and therefore little kinetic energya. Go back to 1st grade physics bud
@@henrygaraffa5439 Probably thinking of some motorbikes there. 11k rpm redline is fairly common, plus the engine will still be right under your nuts. That said, flyweels are scarier.
I like it. I have a downhill mountain bike. Imagine this concept on the downhiller. You brake all the time. Could use the flywheel to boost off jumps or when it’s time for a short pedal between downhills. I think you got something here if you refined this. Although I wonder about gyroscopic forces on the bike and how it will effect turning and stability.
That's surprisingly efficient! But I do think you should still try building a CVT some time because it would really benefit this and a lot of your other projects, you might be able to recover more like 70% of the speed. Since you have access to a CNC machine, I don't think it would be as complicated to build as you might think.
Yeah, IMO he's losing massive amounts of energy to heat as the clutch slips. You really need a near instant clutch engagement to recover most of the energy.
Just use 2 hub motors connected by wire with a switch. You might need a gearing system to match loads. Ideally you want about the same kinetic energy per motor rpm, so gearing the flywheel hub to turn the wheel faster is best. But other than that the motor will draw a nice big kick of power off the line and then reduce its power draw.
@@jeffwells641 Same time, he could also CNC a custom flywheel to move weight towards perimeter to take advantage of angular momentum and reduce weight.
That's a nice idea. I quite like it. I imagine spinning the flywheel when going down a hill and then using it to help accelerate up the following hill again when I'm losing speed.
I was thinking of something similar except the flywheel is always engaged with one of the wheels. It would be harder to accelerate but might give an advantage thanks to the higher momentum
I mean, there's no point in spinning it up while pedaling. The entire idea is to recover the energy that would otherwise be wasted as heat by braking with conventional friction brakes. Instead, you're doing nearly 7 times as much work to store that energy as you would have used just to accelerate from the stop that much by pedaling, due to the 15% efficiency (a loss that isn't present in the pedal-only method). What this _could_ potentially be used for is for storing energy while coasting downhill while maintaining speed, to then be used to continue to maintain speed on the way back up the next hill... but I think you'd need a real CVT for that. And a much better flywheel that isn't quite such a rickety, terrifying mess, and that can preferably go to _much_ higher RPM to store a whole lot more energy. However, I think by the time you do all of that, just adding a regenerative braking system with a capacitor and either a large enough electric motor to reuse the energy, or a smaller motor driving a flywheel electronically, would be much simpler. The electronic systems would basically behave like a CVT but with a lot fewer wear parts and a lot less noise. Also, just FYI, tire weights are designed to go on the inner surface of rims, so centrifugal force helps keep them _on._ That adhesive is in no way designed to hold them against pure shear force like that! Finally, all that noise is also wasted energy. Not a significant quantity for the quick stop-go runs you were doing, but waiting at a stoplight or a crosswalk could see a rather large chunk of your hard-earned kinetic energy sapped away by parasitic friction effects.
Yes this is not free energy because extra effort is needed to pedal.... it appears there is a net loss because the effort to start from a normal standstill certainly looks like less then spooling up the flywheel by pedaling ...
Bro my mind blanked for a good 10 seconds seeing your comment xD "Wait I didn't post any comments, the video just got out?" "Or is it actually an old video?" "Wtf is going on there!?"
Really, one for high speed operation and one for low speed operation. Brake using the high speed, then the low speed. Accelerate using the low speed, then the high speed.
Transmission weight should also be "in" flywheel weight. This way no additional weight to bike. So transmission should also be spinning. Pretty interesting mechanical challenge.
Thanks Tom. I'm glad to have found your channel. As a wannabe engineer, it's fun to live vicariously. This project brings to mind an idea I had long ago when I learned about angular momentum: it would be cool to design a bike with weights that ran along the spokes that you could adjust radially to affect your speed. Cheers!
I would love to see how this might work in a situation where you have a downhill to uphill road segment, and see how the flywheel might assist and help propel you up the hill… by like engaging the flywheel to build up energy on the downhill segment and release that on uphill
That would also dramatically increase the efficiency since the clutch can be fully engaged and not slipping the whole time. I'm betting that's where most of the losses are.
Useful if you are in danger of going to fast downhill. Otherwise it's not going to be better than simply going as fast downhill as possible to assist with the uphill. Also it's an extra weight to cycle with.
@@daffyduck780 eh the extra weight not so much, say about 15 lb extra, not a lot on a rolling chassis situation, but you're right, speeding up going downhill is much more efficient, though if it is downhill to a flat plain then it could be very advantageous
If you used this design it would 'help' by most likely killing you. Storing enough energy to help in any way with a hill climb, even a very small percentage of what you lose in having to lift all that weight up the next hill, IF you could design a practical flywheel having the capability to do that, is a pipe dream. The only way it would help at all is if someone installed the entire system at the top of each hill and you jettisoned the entire contraption just beyond the bottom of each hill, where it ran out of steam. Other than that it would be totally practical (NOT).
An infinite CVT would enable you to minimize energy lost to friction within the clutch system. It would be REALLY awesome to see you design a compact CVT. You would also be able to transfer more energy into the flywheel than just matching your half initial velocity magnitude of the bike.
@@jubuttib true, nothing is perfect. Although, definitly would be an improvement. The 2008 Dodge Caliber uses them and boy oh boy are they great on fuel economy when compared with similar weight and power vehicles without CVTs (see comments later below, this argument was invalid)
@@timothysands5537 Really? Interesting, I've yet to ever see a CVT car match a manual in fuel economy (beating a traditional torque converter automatic is a different thing and shouldn't be held as any kind of "win" IMO), at most matching on average due to slightly better city economy, with worse highway performance. It has been a while since I dived down into CVTs, may need to have another look.
@jubuttib oops, you're right. That is a faulty comparison when compared to an automatic transmission. As far as the manual car goes, it has slippage in the clutch mechanism until the clutch's rpm matches the engine's flywheel rpm right? If Tom were to use something like the nuVinci hub seen on bicycles, wouldn't that be better (less frictional losses) than the clutch mechanism? Don't quote me on this, but I also believe CVTs are still able to outperform manual transmission vehicles by taking advantage of operating in the optimal power curve (or was it hp curve? There is a difference). Engine efficiency declines as rpm climbs. CVTs can vary their gearing constantly to maintain the engine rpm as the vehicle accelerates.
Super cool! Not sure what settings you have on your fusion 360 CAM setup but if you haven’t already, adding a finish pass after the rough cutouts for all the CNC router parts would likely improve the circularity of the bores and overall accuracy. Having an aluminum sub plate vs MDF would also help with the overall rigidity and improve surface finishes. Keep it up!
Instead of a mechanical connection, combine the flywheel with two brushless motors: one motor for power and regen at the wheel, and the other on the flywheel. This will give you flexibility in the regen and allow you to recover up to about 85% KE if you can get a controller to manipulate the voltages and currents to get the most out of each motor.
@@jantube358 On the contrary, as the comment stated, you could get up to 85% efficiency. You'd be unlikely to achieve that in practice, but it's way better than the 15% achieved with the mechanical system.
It requires quite a lot of energy to get going for standstill. KERS is more useful for storing energy from slowing down before going into a corner and then using that energy to recover momentum (or building up speed) as you are coming out of a corner.
This would work for me coming home from work because the first half of that journey is downhill with breaking due to traffic lights. A lot of energy could be stored with no impact on my travel time or effort used. Then then I get to the bottom of the hill and need a little push up some rises, it would be sufficient. So it depends on the specific journey dynamics.
This would probably only make sense when going up and down hills, as you wouldn't want to go down hill too fast, but would want some assistance going up
The only problem is all the added weight, the flywheel adds 12 lbs to the bike, that’s a lot of extra weight to use to get up a hill on. Though I think it would be interesting for higher speed cruising on road bikes since you could store energy without breaking when at high speeds by letting the bike coast and then use that energy to accelerate when getting hit by a gust of headwind that would typically slow you down by quite a lot
@@brisingrxm6022 you need a flywheel with big diameter and weight only on the edge. Like a small bike wheel with lead "tire". Less overall weight for the same capacity.
You could try building it inside the rear bike Hub in between the spokes. You could also then put some of these aero plastic covers over on top of the spokes, making it basically invisible and also more aero dynamic and the flywheel wouldnt have to fight against as much air as it had to before. Im thinking of a mechanism somewhat similar to drum brakes they used to have inside of bike hubs
when you go to take off, just like a car "give it gas" or in this case... start to peddle when taking off and then use the clutch, idk what I'm talking about but I feel like that will make you go faster or push you farther.
Good point. I think his demonstration with starting from a stop makes for an easier data point. But your right, I think his setup would do best in real world cycling after making those first couple pedals. Better yet, regen descending a hill, and using the flywheel to get up the next. Might take some skillful gear choosing to make the best of it though.
If it was a smooth, refined system you'd certainly pick up the beat way to use it in your application. But energy recovered is still the same, there are friction losses as the flywheel spins up, and friction losses as the flywheel is re engaged, so it isn't going to be great, it's only the recovered kinetic energy of your body and bike, that's not a while lot anyways.
This idea is stupid. He is only demonstrating what we already know. The flywheel would have to be MUCH heavier to be of any real use. But that would lower the overall efficiency of the bike.
@@tarstarkusz He could use a heavy weight but that still won’t produce an efficiency of more than 15%. Adding more weight would make it harder to get it going but also deliver more punch when getting going. Either way still outputs the same energy as being put in. (Of course at the 25% efficiency)
Well it's a good idea if you want to make your legs work even when your commute is usually very flat terrain, also I'm guessing it's easier to control your bike on a descent with a flywheel as normally you either wear the hell out of your brakes or embrace the madness that's going way faster than it is safe.
@@cdgonepotatoes4219 I doubt it would be noticeable on e serious decent where you would need to break hard for a long time. The flywheel will just get up to speed in the first few seconds and not do anything after
It would be some what dangerous...but I wonder if there is a way you could store the energy in a strong spring instead. The way garage doors do. Springs are the best at storing mechanical energy. Because they are essentially like mechanical batteries. It would make an excellent braking system for sure, because it would brake with progressively more force the longer its engaged. And if it had a locking gear system, that only released upon command, you could store that extra boost as long as you needed. It wouldn't be quite as dangerous, if the spring could be stored some how within the tubes of the bike frame itself, so they couldn't shoot out, if snapped. Its not something I could build, because I lack the tool and experience. But based upon what you made, it seems entirely possible. In essence turning your bike into a wind up toy. Except it would wind itself up while braking with a clutch. Seems like you have most of what you need for the idea done. If you modify the flywheel to wind up wire rope instead, conceal some springs safely in the frame or in a sealed add on container, and run the wire rope with welded pulleys. This concept would be much more effective. Another benefit is that you could utilize the boost whenever you'd like, from a dead stop to get you going, to help you up hard inclines, during the middle of you peddling when you're tired, or even while you are peddling at your top speed for like an rpm boost.
@@jocaleb0236 it's more likely that his diy sprockets were less than perfect, the profile matters greatly and even a slight error can cause all kinds of issues. Noise being all but guaranteed.
I feel like this would be counter productive for a couple of reasons, firstly you have to carry a heavy weight with you and that means more work done for a given distance, secondly it can lose angular momentum and work against you when you are turning while it is spinning due to the gyroscopic effect.
Yeah it would help especially when those gear teeth would be lubed and engineered to perfectly fit each other. The gyroscopic effect of the flywheel would also improve balance
It will not help with climbing. It only provides power when the flywheel is spinning faster than your speed would create. You would work harder climbing with it engaged. Wait till the down hill to use it as a brake or engaged all the way down for elec generation?
As others have said I'd like to see how the efficiency numbers change once everything is lubed up! Also I'd imagine the real world function of the flywheel would be to assist in pedaling rather than used alone, so a qualitative improvement vs no flywheel takeoff would be interesting too.
Im also curious to see that, AND I would also like to it with an additional flywheel. where there is one that is captive to the rear sprockets and wheel and a rear sprocket with additional speeds as space allows that would allow for ease of driving the rear wheel’s flywheel up in speed and the extra mass of the flywheel being attached to the rear wheel/sprocket would allow for better maintenance of momentum when cruising. I also think that in conjunction with this there should be, for the current under frame flywheel, a set of gears specific for each action of the flywheel that have the best mechanical advantage for each action. Being that the flywheel may be spun more efficiently by one gearing in order to be accelerated by the braking force, but a second gearing on the opposite side for applying the flywheels torque back into the bike’s normal gear system after a stop could prove more efficient than the current gearing that has to do the job of both accepting and returning the energy in both directions
I'd like to see how it does with the flywheel used like a battery. Like how some old transit buses did with each stop having a recharge that topped it back off to 65k RPM.
Where you would gain a lot of efficiency would be to seal the flywheel inside a vacuum chamber. This is what they did on the prototype cars in LMP1 or at least I know that's what Porsche did for theirs.
I think another issue (besides it just not having much energy) is that it won't speed you up if you're already going faster than it is. Then it will just slow you down more. So unfortunately it can't be used like a nitro or something. At least, not without including an extra gear shifting ability that could gear it up or down. Which would be cool, yeah. But still probably enough energy for much.
@@mikegutsch5769 Did you see the assist it got from just a standstill? Imagine going uphill. You just carrying 6kg of dead weight all the time for that miniscule of boost. You are better off drilling holes in your bike for saving weight and saving energy that way.
I can see this being part of an enduro bike. When going down the hill, with gravity the energy from the rpm of the wheels is stored at the bottom of the hill, and when you start to go up, you can release it and get quite a boost to get up to speed
I see a great application for this as being able to slow someone down on a fast down hill, but accelerate it back up for when the slope changes into an uphill
3 years later and re-watching: I feel that the real application for this bike would be to ride down a hill, clutch engaged, at the bottom of the hill coast, and when you start to slow down engage the clutch to coast further. Sounds fun!
3:57 solution is to CNC the holes slightly (maybe 20 or 30 thou) undersize, then finish them with a reamer or endmill of the specific size required. Ideally that center hole would be drilled/bored on a lathe but the endmill/reamer method works too if it's done right. Cheers!
I was thinking the same thing as a simple solution. Might want to take a look at how that router is interpolating the holes, too. Simple tool path change might solve the problem…
Definitely seems like the application of this tech would work best on a downhill slope. You wouldn’t have to pedal to give the flywheel maximum speed because the hills potential energy is being stored in the flywheel if it’s engaged while going down.
Love the bravery of this guy to test out an experimental, self-modified, imperfect prototype bike while not wearing any safety gear whatsoever. Engineers scare me.
What about a design where the moment of inertia for the bike wheel can be manually increased/decreased with weights on the spokes for example? To store energy and decrease speed you move the weights out. To recover the energy you can move the weights back to the centre.
Hmmm You could use some of the centrifugal force to push the weights out but pulling them back would be much harder to design.. Maybe you could use the rotation around the axle to pull a wire or something but that is a bit of a nightmere. As I understand it moving the weights out though would cost as much speed as you would gain in your moment of inertia
This concept works better on an adult tricycle. You can mount a heavy (80-100 lbs.) flywheel and use the crank to spin it up while stationary. You get a great launch from the heavy flywheel. I once read about a man that invented a car that used this concept but with small motors to spin the flywheels as well as breaking force. Fun stuff.
yes. Ideal for those hilly countryside trips where I never want to stop when I reach the bottom each time, as I always want to use my momentum. Sadly, often there are traffic lights or a give-way at the bottom stealing my energy. A flywheel would solve this.
Be carefull with this. A rotating flywheel wants to stay in the same plane. When standing still this is no problem, it even helps your 'sur place'. But while driving, it wants to go in a straight line, decreasing maneuverability.
This would be a great concept for those who live in a neighborhood full of hills where you would need to go up and down frequently. The flywheel could be used instead of the brakes when going downhill (for the most part), then the flywheel could be used to (somewhat) assist with going uphill, thus making the climb a touch easier.
Our boy Stanton: "I heard you liked spinning wheels, so I put a spinning wheel between your spinning wheels so your wheels can make the wheel spin when they spin!"
technically it's supposed to be the wheels make the singular wheel spin when they unspin, but yeah , something like that is kinda correct too, since it has to charge up from riding as well
Cool. i did this too in 2003. My flywheel was a 26" mtb wheel with 6 guage copper wire wrapped around to evenly distribute weight. I removed the top tube and installed a split top tube for the wheel to slip thru to fit it on a mtb. I left the cassette hub with 7 speeds on it so I could really get it up to speed. So Yes I had a pair of grip shifters and an extra thumb shifter on the bars.I did not use a clutch, though my friend wanted me to do that to do "burn outs". The end result was it was too much of a workout. It did seem to help getting up a hill after running down a hill.
Heavily discounted lunch can still add up over time, my friend who rides a lie-down bike would probably want such a system to help in city traffic and to store some down-hill energy for later up-hills!
@@andreassjoberg3145 but it's additional weight! Tho you can make it lighter with a big wheel that has most of the weight only around the edges. Like a small bike wheel with lead "tire".
Of course there is. You guys are providing it. Giving him patreon money, and YT ads plus his own ads. That is free breakfast, lunch and dinner. SUCKERS.
It seems like this would be most potentially useful in hilly terrain. Being able to capture extra energy from a downhill and have it assist you on an uphill would be a nice little boost.
@@friederich66 flywheels are essentially batterys. Electric cars do the same thing, recharge while going downhill. There's no violation of physics laws here.
@@lucascurtolo8710 and i am Not talking of batteries but of that stupid flywheel! We already have e-bikes.just hold a rotating bike-eheel andtryto tilt it, and you See what will happen: the wheel will try to move in a different orientation, it IS nearly Impossible to hold it. that is the force that holds a Bike upright.
@@friederich66 I'm not saying it's a good idea, just noting the only possible use case. As someone else said, great to have a high speed flywheel rotating right beneath my groin. Saying it violates physics tho is kinda crazy
The main problem and reason for the inefficiency is the direct coupling. To build a system that is capable of transferring 100% of the energy to the flywheel, you need a variable speed coupling. I am not sure if that can be achieved using a hydraulic coupling, though the most efficient solution seems to be with an electric motor / generator on both the wheel and the flywheel.
Hey Tom there is this video on a simple ball CVT by “funtastyx” that could be just the simple and compact CVT you need to make this flywheel more effective than using a clutch that can slip.
The main problem with CVTs is that they are not very efficient, but they might add more efficiency because they would reduce the requirement for using the bike's brakes.
@@ArchieHalliwell CVTs were used in some early hybrids/eco cars because their efficiency is really, really good. The problem is that they can tend to [fail/slip/underperform/lose efficiency] at high torque/speed conditions. As in, 7000 RPMs in a car moving 2.5 tons of weight. Not at 2000 RPMs moving ~300lbs of weight. 'Course that would depend on the CVT in question and your tuning. A perfect CVT would, by definition, be the best possible transmission in all scenarios. The only reason they aren't is slippage. The tech has and will continue to get better.
The solution I have used for not round holes on a cnc is to plunge the end mill to create a pilot hole in the center and then finish it on a drill press. Works wonders.
Here's an idea! A much more efficient way to contact the flywheel would be to use a torque converter. It's a common car part that's connects the engine shaft to the drive shaft of the transmission. It basically uses two turbines and a fluid to transfer the energy between the two drive shafts. This would not only make the system quiet but also increase its efficiency.
Also, a torque converter takes a lot of energy to run just by itself. It's why an identical pair of cars, one automatic, the other manual, will perform so differently. The manual will always be quicker because it takes a lot less power to spin the manual gearbox than it does to spin the torque converter. The reason cars can get away with it is because they only use it for initial acceleration; the converter locks together for a mechanical linkage at cruise speeds. Some automatics, famously the ones Toyota uses in small 4-cylinders, are very efficient, but you can't reasonably expect a hacky home job to even approach that. So, far from _more_ efficient, my guess would be there'd barely be enough energy to even spin up the fluid, let alone the flywheel, in the low-speed braking runs he was doing there, and the efficiency would drop to very nearly zero. An electric equivalent is a _much_ better idea, IMO. It could continue to convert braking energy into flywheel energy all the way down to a stop. The flywheel could also be enclosed in a partial vacuum for safety, noise reduction, and efficiency. A small capacitor could be used to be able to translate between quick stabs at the brakes and the slower spooling-up of the flywheel, and overall the whole system would be far more elegant, IMO.
Loved the video. Some of the real world benefits I can see from this is acceleration smoothing on hills better than stopping and starting. Less smooth start help and more hill climb assist. Going downhill would enable more spin-up input energy and then engaging the flywheel would help assist in pedaling through the climb portion. Love the whole concept and now I want to build a flywheel alternator mod for an electric bike. A switchable one so it either discharges the flywheel speed as mechanical energy or just keeps spinning to charge the battery when not pedaling.
What would be cool is a way to power up the flywheel while the bike is stationary. You approach the red light, use the flywheel to slow down, (getting some RPMs) pedal a bit while waiting (gaining max rpms) and then engage the flywheel to accelerate quickly when the light turns green
That would actually be really good for cities! As you're coming up to a stop light, start sending the energy into the flywheel, and then once it's green, use the flywheel to get yourself going. The launch always takes the most amount of energy out of you so this would really help
Ummm. Or you can do what skilled cyclists do all the time. Plan your arrival at a stop light so that it is green when you arrive, avoiding braking. You might be able to simply slow or stop peddling and allow frictional losses to slow you as you approach a stop, and if well done, you wont need to come to a stop.
@@sebdapleb1523 My comment: Your reply: Sorry, I don't understand that at all. How does a flywheel help you avoid a collision with a bus while riding a bicycle? In my cycling experience, busses are never a problem ---their drivers are skilled and patient and they keep safe distances from cyclists to avoid having to fill out all those company accident reports! I'd rather be passed by fifty busses than one average motorist. I'm guessing you don't do much cycling?
This seems like the perfect application for a CVT. With a CVT you could ramp from full speed to nearly stopped all while still putting energy into the flywheel. I would estimate you could get close to 50% efficiency this way.
Anyway, I think it'd be interesting to see the effect of a big gyroscope in the bike's frame or in the wheels. It wouldn't want to turn in certain ways. You might be able to do gravity-defying maneuvers with one of those, mounted on a gymbal (sp?).
@@flishry in order to turn a bike you make a small turn in the other direction just before you turn the way you want. This shifts your centre of gravity in so you don't just fly off the outside of your turn. Any gyroscope strong enough to correct an ice slip would probably be strong enough to stop this minor corrective pre turn turn. As a result you might not fall off from ice, but any attempt to turn would throw you off the bike.
I suppose not unsimilar to motorcycle wheels at high rpm (30+mph). Seems like a feature. I wonder if the ideal gyrocycle would behave like those gyroscopic unicycles. Then you could keep peddling while stopped at traffic lights to recharge the flywheel.
You should try to use this to climb a very steep hill. One reason steep hills are hard, even with a very high gear ratio, is because it becomes more difficult to generate enough inertia to take you from one pedal stroke to the next. With a flywheel you should be able to store the inertia to carry you from one stroke to the next without slowing down.
Oh, Boy! A homemade, high-speed flywheel rotating just beneath my groin!
Yay!
The sound alone is harrowing. It's like something out of Greek mythology. (Still awesome, though, in a mad scientist kind of way.)
Needs more jagged edges. Use a dia-tipped Sawblade...
If you want your boys snipped, look no further!
ok
Amazing, I love a bike build/project and this was spot on
Woah sup Colin!
I found you first I guess
definitely need a Colin and Tom Collab project
High praise right here!
You'd use fireworks to spin up a flywheel to make a bike boost
0.086mm error when drilling holes, 2cm error when hanging pictures on the wall ;-) priorities!
@Peter Evans lame
The sound coming from these gears made me appreciate how well made bicycles are
That's why bicycles have chains and not gears ;) they are much more efficient, have much less wear and takes a lot less maintenance than gears.
It's no just a matter of noise.
Let's all just take a second and thank the guy that invented the chain.
@flymali691 ...what are you thinking bicycle chains are typically attached to? Upon a second glance, the noise here seems to be coming from the chain making poor contact with the front gear just due to the lack of chain slack. He could have gotten rid of his weird excuse for a chain tensioner, since it's a single gear ratio, then just actually tensioned the chain directly. But given everything I've seen, I don't think this guy has a working relationship with bicycles
@@tay-lore A gear is specifically something that interlocks with other gears whereas a sprocket is specifically designed to work with chains. Sprockets and chains go together.
@@TheInfectous ah, I see. This guy's sprockets sound shit
@@TheInfectoususually* interlocks with other gears. Also that’s for English. In my language both things are just called teeth wheels directly translated
Get the flywheel up to high speed when going down hill, then use that energy to assist when climbing the next hill.
Sadly it doesn't work like that
Ya so basically if you were going down a hill you would normally use breaks on, you can recover some of that energy into the fly wheel.
But if you would not normally use breaks to go down the hill you would be better to just let your inertia handle it. Less steps less loss
The most practical application for that sort of system would be something where there is an overall drop in elevation with steep hills down where you have some reason that you cant just let your speed go up and down as you pass over the hills that youd likely already clear with the overall downward slope
@@squirrelspown My city has a ton of relatively steep hills with regulated crossings at the bottom, so the use case is very real sometimes. If only the implementation wasn't mediocre at best with a flywheel
@@nonnodacciaio704 If you'd have to use your brakes to slow yourself down under normal circumstances, yes it does. Not having an infinitely variable gear doesn't help but it should still work. Clearly it won't get you all (or probably very far of) the way up the hill, it will get some of the way up for free.
@@MrCh0o
Ya that makes sense
but....like he described in the video though, one might infer that the best case scenario is if you never come to a full stop.
At best reducing speed by up to half before you lose your storage.
so if you need to stop at cross walks you may loose alot of the theoretical benefit by dumping a bunch of energy into breaks
So im just spit balling here....let me know what you think
I imagine the optimal workflow would be leaving it engaged and peddeling with assistance the whole way so all you need to do is overcome friction losses and any positive delta
and the flywheel sort of governs your speed sort of just acting for you as if you had the inertia of a large object even though you are a small one.....but you dont get the potential energy benifits of being a large object
Does anyone know how the math works out on that?
if speeding up and slowing down is required i imagine you would peddle hard on the way down to charge it diss engage completely while you look if you need to slow down or do slow down.... try to get back up to a solid portion of the disengagement speed and use it to push up maybe 1/3 of the hill?
Achievement Unlocked: Tom Stanton has advanced into the Iron Age
Metal
Advancement Made!
Aquire Hardware
@@spod2998 lol
Lol
from pla
There's a HUGE problem with flywheels, as a large mass rotating at high speed introduces unpredictable changes in behavior of the entire system, when turning left or right.
I mean, its gonna keep the bike up a lot harder, though only when spinning. It would be interesting to feel the difference
Seem like you'd have to practically stop to make anything more than a slight turn. I would think that the energy to turn the flywheel has to come from somewhere, too, which means more effort for the rider. But I am totally out of my element with physics so I could be completely wrong on that. Would be interesting to see how it compares to riding an actual bike with some of the physics explained.
@@tastybluecrayon the drive train (engine, gearbox, etc) on a motorcycle is like a big flywheel in the middle of the bike, and when you're maneuvering with the engine fully engaged to the wheel vs the clutch pulled in and the engine idling there is a noticeable difference in how it handles. I don't think that turning on this bicycle would be as hard as you're saying, but it would feel heavier to lean left or right.
@@MortimerJones99 Its harder to turn due to the gyroscopic forces of the wheels, not due to the engine.
The flywheel is between the engine and the clutch, clutching in and out only disconnects the gearbox and front sprocket, way less gyroscopic force than even the crankshaft itself.
You could however solve this problem with bicycles by having two flywheels, one on the front axle and one on the rear. Will feel weird when stopped or going slow, but shouldnt impair turning, in fact i think it would apmlify it
@@SportSoulLife He means when your driving, with the engine up at its running RPM vs having the clutch disengaged and the engine idling all while rolling along at the same speed. Your bike is moving at the same speed, but the engine isn't turning anywhere near as fast. Thus less gyroscopic stabilization.
You need a 19lbs plate and a transmission to a higher gear ratio to get more value out of the discharge. You'll see a dramatic change in how aggressive the takeoff will be. A sort of tapping of the clutch can get you up to a pretty high speed. I'd recommend doing the transmission from the other side of the bike.
A sort of 2chainz bike if you will.
Ok. The stupid joke made me smile.
My preference is the Spec Clutch. Only cause Mitsubishi Evo. :) You could change the Clutch to a better one. I'd also recommend Volk Racing Rims for bikes like yours :D. I've also heard Corbeau makes really awesome bike seats!
Would it affect how hard it is to pedal the bike?
If so, how much more would it possibly be?
Tity bike
has the added bonus of sounding like a TIE fighter as you ride by your friends.
Lube. Lube those gears. You’re losing a tremendous amount of energy in friction on those chunky cogs.
Everything can be fixed with more lube.
everything.
@@100acatfishandwillbreakyou2 No, not everything… around half. The rest being solved by duct tape.
Big difference when you lube a chain. Feels like the bike is 25 lbs. lighter!
@@thelakeman5207 I agree. I build high speed gearboxes for a living, not only will it turn with far less effort, the teeth will last 1000x longer. A wet gearbox is a happy gearbox.
@@Whiskypapa what about flex tape
"from breaking loose at high rpm" - he means: "from slicing me in half"
I’d still be scared of the flywheel that close to my genitals…..
its pretty dull. so maybe "grinding" is more likely :D
The grinding is there to scare you genitals.
Getting your Prince Albert piercing caught in the mechanism probably isn't gonna end well...
Name for the bicycle.... "The Castrator"
Going down a hill you could get the RPMs up really high, then use it to help with going up the hill on the other side.
Isn’t the emount of energy the same? The flawheel stores some energy but you also have to carry more mass climbing up
@@ImadogGarcia Yeah, presumably -- but it's so much fun zooming down a hill that you can pedal fast and not notice.
@@ImadogGarcia Theoretically but due to the laws of physics it's unlikely you'd get even halfway up the hill with just the flywheel
No one said you'd be using just the flywheel. Gentle effort plus mechanical assistance means you're flying up that hill, same as E bike. @@squidwardo7074
Stolen Comment
Tom, you need 2 gears for the fly-wheel, a high gear-ratio for slowing down and a low-gear-ratio for speeding up, think of this this way when equilibrium is reached you want fly wheel speed high relative to wheel speed, but when speeding up you want the wheel speed to be high relative to fly wheel, anything inbetween can "solved" with your clutch.
This is what I was thinking with 2 clutches... But probably has diminishing returns as the larger mismatch of speed across the clutch means more lost energy as heat.
@@JamesUKE92 I agree, 2 clutches with their own gearsets. Braking force will be much higher than acceleration force, but that's exactly what you want. You'll have a small assist accelerating up to a much higher speed.
The problem is not a lack of torque, it's a mismatch between the speed of the bike and the flywheel. All the time the clutch is slipping, it is wasting energy. But as soon as it engages, it is no longer transferring power because the speeds match.
As he says a couple of times, he needs a continuously variable transmission so the flywheel can accelerate as the bike decelerates.
Maybe CVT actuated by hydraulic brake levers may be solution. That would give variable ratio gearing. Also clutch mechanism functionality could be achieved by undertensioning belt between CVT wheels.
@@vyrukas2 The simplest solution and probably the most energy efficient on small scale is to use an electric generator and motor (or ofc ditch the flywheel and use ultracaps or high amperage batteries).
Needs a sprag clutch on the flywheel in series with the clutch, so that when decelerating it automatically disengages when the flywheel exceeds the bikes speed.
There's a slight issue with that. You would go from decelerating at a fair rate to instantly freewheeling. I was thinking the same thing but I reckon it would be a bit hairy having that occur.
@@Alan_Hans__ How about in tandem (if there is space enough) with a centrifugal clutch?
A centrifugal clutch linked to a centrifugal variator is kinda what is needed. Someone posted some info in a comment about a super simple ball CVT by “funtastyx” that could possibly be integrated somehow. With a 3D printer and a NC router there's a lot that could be done.
I also reckon a car flywheel would be a better option as well as more of it's weight is further from it's axis which make it a more efficient use of the weight.
@@Alan_Hans__ it would an already is a deminishing braking effect, as the speeds begin to match it brakes less and less, wouldnt go from all to nothing itd be gradual.. the issue with the sprag clutch is youd need a way to put the energy back to the ground, either a whole seperate clutch and lever or some way to take the sprag out of the system for acceleration..
i think itd be a fine system if the flywheel weight alot more, with it weighing less than the bike the speeds match each other far to quickly and theres not much energy in the flywheel to accelerate you, and if you dont use the energy after a stop it doesnt have much braking effort left for the next stop either, with a heavier fly wheel and a higher gear ratio for it to spin it far faster than 2300rpms.. like 10k-15k rpms youd be able to store multiple stops, long descents down hills where it isnt safe to just build max speed you need to brake.. might be able to store enough energy in it to actually propel you to cruising speed or assist meaninfully in hills at that point
Tip for the flywheel: Because the mass at the outside of the flywheel has more rotational inertia you would have better performance using a thin central disk, and welding or bolting thick rings on both sides to make the cross section an I beam. For the same volume/mass you would have a much higher rotational energy saved up at the same RPM. :)
Hmmm yes yes🥸
Adding razor blades would deter thieves and make it safer.
@@ghlibisk67 sure it would keep it safe for the rest of your life.... which happens to be about 3 minutes longer than it takes for the glue to fail launching the razor into your femoral artery.
Science bitch!
IT willl not work. Try to hold bicycle by the hotizontal axis , put it in Rotation and try to tilt it. You will feel a strong force that tries to move the axis in a vertical position. The Same will happen with the flywheel when you change the direction in a bend. And why all this effort? We already have the E-Bike and we can use Rekuperation like an a car
I think a viable use-case for a flywheel is on a trike. You pedal at a constant speed more or less, not exhaustingly hard (< 200W), including while stopped. Then you have hopefully cached up enough energy while sitting at traffic lights to have decent accelleration without needing a lot of Li batteries that are too expensive for their service life. A flywheel applied this way should last forever. Probably there is a known name for this concept.
who tf sitting at a traffic light on a trike?
@@JustKhari You'd be surprised.
@@JustKhariI would. I used to commute, train, and race from 1986-2012. In 2001, I had my neck broken in 3 places, C3, C5, & C6. My neck is fused from C3-C7 (entire visible part of your neck). For me, what would be a normal fall for you, could be potentially disastrous for me, quite possibly the next break would be at C2-C3, or C7-T1.
Best case scenario for C2-C3 is quadriplegic, but more likely killed. C7-T1, best case paralyzed from the waist up, but most likely quadriplegic.
So, if I want to ride again (and I miss it terribly) my only option is a trike.
That’s who tf, would ride a trike.
@@JustKhari literally anyone who uses a trike and has to cross intersections, what else do you want them to do? blow through the intersection while cars are crossing?
@@JustKharijesus christ what do you think a traffic light is for? I cant think of a single vehicle(including a bicycle) which is exempt from traffic stops. you must be from the bayou.
"However, you can't charge and discharge this batterys not nearly as fast as this flywheel..." Sounds like a new Super Capacitor Project :-)
Agree
Or could motors be used to create a electric infinite transmission between the wheel and flywheel?
@@TheNateDawg94 That was my first thought actually. Clutches are very wasteful.
@@nrdesign1991 especially if you need power but the flywheel is spinning slower than the chain...
I was going to make the same comment! I immediately thought the same thing upon hearing that exact quote.
Now you need to design a CVT to transfer more more energy into the flywheel instead of wasting the remainder of the momentum in brake pad heat. Also, with a different spoke design you might be able to place a 26" flywheel concentric in the wheel. The larger size could store more energy at lower rotational speed.
@@lIIIIIllll Do you know how CVTs work? It wouldn't eliminate the need for a lever. You'd still need to manually operate a clutch to engage the system. What a CVT would do is massively increase the efficiency of the system. Tom made a little diagram showing how the flywheel and the bicycle wheel eventually reach the same speed, but with a CVT it would allow for the flywheel to reach speeds faster than the bicycle wheel.
@@XiuHang also variable ratio for powering the wheels back up to speed more efficiently
@@lIIIIIllll I'm going to be very straightforward here and try to be as not mean as I can.
Your comment is quite literally the dumbest take possible on the use of a CVT in this scenario. The use of a clutch lever in this situation wouldn't be to actuate the transition of the CVT from lower gear ratios to higher gear ratios. The use of a clutch lever in this situation would be to engage the entire system. The KERS shouldn't be functioning at all times; it should only be functioning during stopping and starting, so you use a lever to engage the system when you're stopping and starting. Then if the CVT functions properly, you couldn't just use a CVT system from a scooter or car you'd have to design one for this specific use case, it would incredibly increase the efficiency of storing energy into the KERS and retrieving energy from the KERS.
@@lIIIIIllll I'm going to reply here then stop because at this point I think you're intentionally being obtuse.
First, I never discussed anything near physics; I described the very simple mechanical reality of a single gear being less efficient than a CVT in regards to energy transfer from one rotating object to another.
Second, I didn't even push the idea that Tom should design and build a CVT. I pointed out that a hypothetical CVT would still need a lever for engaging the KERS.
Third, this hypothetical CVT wouldn't even be that complicated to build. You could almost entirely use scooter CVT design; you'd just have to tune the centrifugal spring mechanism to operate at bicycle speeds instead of scooter speeds.
Finally, Tom literally build his own electric motor for a video. Would it really be that surprising if someone who enjoys building e-bikes and e-bike related things built a CVT for a KERS?
@@lIIIIIllll I genuinely thought I wouldn't respond to you again, and I've made a promise to myself to not respond again no matter how stupid your response, so this will absolutely be the last bit I type here:
1. You don't understand chronologically linear steps. (See your step 6)
2. The lever in question is to engage the KERS and start spinning the flywheel, I don't even understand what you think I'm talking about. Are you trying to imply that I'm referring to the internal clutch in the output?
3. KERS stands for Kinetic Energy Recovery System. Yes we are talking about a KERS even if it is purely mechanical and not electronic.
4. Your worry about slippage is genuinely stupid because we're working with a damn human as the load. Less load means less torque necessary. Less torque necessary means less friction needed on the CVT to prevent slippage.
5. The tuning would be to make the CVT work at bicycle speeds not "human size."
6. Your point 9 is accurate, but once again I wasn't the one who was suggesting actually building a CVT. I was pointing out the logistics of operation and hypothetical efficiency.
7. I'm now absolutely certain you're being intentionally obtuse because you've misquoted me, responded to points not made, arbitrarily tried to alter the definition of a term being used, and ascribed motive that wasn't there.
If you're a troll, congratulations you got me. If you're not a troll you might want to pick up that mic and use it to ask someone to teach you how to read again because you have clearly not read the comments you've responded to.
Why not use a circular spring to store rotational energy while braking, so you can store the energy for a large amount of time without the flywheel slowing down? That'll come with the added advantage that you're not adding as much mass to the bike, you only need engage the mechanism while braking, and it won't be as noisy.
Thats an interesting idea... so a spring, like a mouse trap!... and it launches you forward... as long as it doesn't launch you backward! :)
It might not have the torque to get you going again though, But good Idea.
Thats called elastic energy and is much more limited in the amount of energy that you can 'store' in the spring. Compared to a flywheel.
Its all old idea's in a new jacket. Has been done centuries ago. Not very effective.
@@Reach3DPrinters more like a big clock spring.
@@SuperUltimateLP
Beat me to it.
I found myself nodding in understanding multiple times through this video lmao you're so good at explaining these things without having to dumb down the concepts
Hey, that sounds like an amazing Sack Shredder
You'd be LUCKY if it ONLY cut into your nuts and NOT the sac getting CAUGHT and WRAPPED around that terrifying *Infertility Wheel* at full spin...
It reminds me of when I rode a Yamaha Virago motorcycle which had a mono-shock rear suspension. The one shock absorber was positioned oriented horizontally front to back under the seat. And it was filled with nitrogen at a pressure of 150 to 200 psi.
I'm actually curious as to how effective the flywheel could be in maintaining the speed while coasting rather than using the energy to take off from a start. Just a thought.
So whatever momentum stored in the flywheel, is taken from the momentum that would've been stored in the bike. But if its propelling the bike, the bike will coast almost as far as it did without the flywheel. A little less due to all the friction.
In order to get the energy into the flywheel it uses the momentum of the bike, so it causes the bike to slow down but the flywheel spins up to top speeds. It means any amount of momentum you use to spin up the flywheel slows the bike, so the only way to benefit from this is to use it for a brake, for only when you have to slow down or stop anyway. Otherwise if you tried to use it to coast you would first have to pedal up to speed, then engage the flywheel in order to get it spinning, but this will slow you down anyway, and all you would be accomplishing is going faster, then braking, then going faster, then braking, etc... It would be a waste of use, because you could just avoid it all and just keep pedaling and you will get their faster, and with less energy.
The only way to use it to actually benefit, is the way the guy in the video plans to use it, as a brake. Hey, be happy, this is a awesome regen braking apparatus, all mechanical no electrochemical batteries..
@@TheRebelmanone the efficiency is comparable too! And he's just one man with not very precise equipment (according to him).
I imagine it can be much more efficient (% wise, not compared to ebike) if it's industrialized
@@collinmckinney6952 ok lets make it turn on oil film.
I can already imagine V2 of this bike:
Tom pedaling next to you at a red light.
You look at him weird.
Then green light > clutch engage > zoom away.
You in dust.
I think the bike would work great on hills. You can store all the excess energy from riding downhill into the flywheel. Imagine Toms smirky grin at the red light on the foot of a hill. Then he goes rattle rattle SWOOSH. Until he has to carry the extra 6kg back up the hill by muscle.
Hehe. "Too soon, junior." SCREEECHHH
You just have to hope. That the red light ain't to long.
Honestly this one seems weird. Cool idea, but acceleration is already the one thing bikes excel at. Any cyclist who uses their gears well can smoke cars at an intersection.
Wind and hills are the primary enemies of a bike.
@@unything2696 yes, you could also spin up the flywheel using a motor and use it as launch control.
Cool concept! What if you used a torsion spring instead of a flywheel? Might be lighter, plus there would be no time limit on stored energy. Could add some kind of ratcheting mechanism so that it can’t propel the bike backwards while tensioning the spring, and then probably another handle would be needed to engage some kind of reversing gear and release the spring tension 🤷♀️
Must be nerve wracking knowing there's a heavy metal disc rotating at thousands of rpm right below your nuts.
No worse than a motorbike :))))
@@cbwcjw Ya really id rather that spinning disc let go than a V twin blow up under my wedding tackle.
The burst strength of even a 300 series stainless flywheel would be impressive. Also it's under the top tube.
There's worse things.
..I thought he said "nerve wacking".. nevermind.
That’s great. Now I know why bikes never use flywheels.
They use it (sort off) but more to have a bigger impulse and make it harder to slow down, and not to break/accelerate easier
This is not worth the noise and effort.
I wonder how it will influence the bike's handling when doing a quick turn with the flywheel at full rev.😬 Great project b.t.w.
@@ottonormalverbrauch3794 yes it most certainly will. Gyroscopes are nothing to hyuck with
Adds heavy disc to capture energy when stopping. Increases mass of bike so it takes more energy to accelerate again.
do you shit first before you ride a bike ?
Everything here screams waste....
@@Deontjie Other than it being a project to further one's skills and understanding. I liked what he did in the middle, ignoring the braking part and just seeing whether the flywheel at maximum speed could even accelerate him much.
@@Deontjie Yes a car engine flywheel screeam waste, engineers are assholes.. and you a genius... 😑
@@nopochoclos Yes, you got most of it right.
I had an idea like that before, but have never been disciplined enough to invent things.
My main idea was for the gyroscopy to help with balance at red lights, but releasing the power for a head start is pretty clever too.
Sounds like you were losing an insane amount of energy from vibration and friction
TH-camr: talking about raid-
Literally every soul in this planet: *SKIP 10S SKIP 10S SKIP10S**
Don’t give away our best secrets
Yeah, not a good advertising partner.
Me: Installs SponsorBlock
i highly recommend setting the skip time to 5 seconds to make rewatching faster :)
@SyzTeMaTiC only 1k? That’s a laughable amount of cash for larger youtubers I’d imagine and they still take the sponorship
I think I would LOVE this arrangement on particularly hilly rides. I'd use gravity on the downhills to spin-up the flywheel then release that energy for a boost at the base of the hill and the start of the next climb.
creative
*Yeah. It will be a real pleasure lugging that heavy flywheel up the hill. it weighs more than an bike-sized lithium storage battery. I'll go for the battery, thanks.*
The weight of the flywheel would more than offset any benefits on a climb.
@@JoeOvercoat Good point. In the end, energy is never free.
I was thinking the same thing, but also to act like a engine brake on a car to slow you down, but it will store energy like an e-car
A bolt on kit could probably be made or combined with an existing engine based design to help improve efficiency. It is quite impressive that you've managed this with simple machining tolerances limiting you. You should try a design with the flywheel weighted towards its edges (i.e. thicker towards the edge or with a heavier metal bracketed around the circumference of the flywheel!
This seems like it would be useful on hills, gathering momentum in the flywheel downhill to help uphill
And when you're stopping at traffic lights, because you can get half of your speed back for more or less free
Unless there is some reason to brake, though, a flywheel system would be pretty much useless for retaining energy from hills. You *already* retain energy from hills as it is converted to KE at the bottom. The big difference between having a flywheel or not in the case of simply going down a hill and back up is what your max velocity at the bottom would be. This may save you some losses from aero drag, but the flywheel itself would add all sorts of mechanical drag in its own right. Just listen to the hellish clacking and screeching that Tom's rig produces, even when the clutch *isn't* engaged. All that is energy being lost from the bike. Not to mention the danger of a high-speed flywheel mounted on a bike and all the stress that would be experienced by the mounting and bearings due to gyroscopic precession in turns.
The implementation of a flywheel system like this would only be useful for helping to retain substantial losses of energy, such as when braking or from aero at high speeds. In other words, what it's good for: Going down a hill, stopping, then going up a hill. Reducing max speed on large hills to save from aero drag. Bikes that are designed for slower speeds. Straight lines.
What it is not good for: Your average ride across mild slopes. Any instance where you want to achieve high speeds. Bike designs that are already built for low aero drag. Sharp turns.
also worth to mention, that +5kg flywheel is not as small as if an avg bicycle is already around 10kg (a commuter is 15kg)
@@christopherbare9277 The flywheel will allow you to slow for junctions and corners at the bottom of the hill, but it is more efficient to store kinetic energy as your speed rather than the flywheel rotation.
@@hesterclapp9717 nope, more like only a quarter. Compare the graph: flighwheel meets bike speed halfway during breaking. And during acceleration bike meets flighwheel speed half way again.
Without a clever gearbox this won't work out
When he began to say "because steel", there was a small stop, so I was honestly expecting for second for the sentence to continue with "because steel is heavier that feathers"
"but they both a kilogramme"
@@paxreal oh no, no you're not...
@@Nicoviceful I don' get it
@@ThompYT just search TH-cam for "limmy what's heavier"
@@dogbot55 I think he gets it
While I'm sure it's perfectly safe, I'm not entirely sold on the fast spinning metal positioned under my nuts.
At under 3000 rpm, that is way less than 11,000 some engines turn. What are you afraid of?
@@420frankp Those engines aren't homemade, they have a bulkhead and casing protecting me, and aren't placed under my nuts.
@@420frankp yeah okay 11k rpm in what stock car? an rx-7/8 with rotary only redlines at like 9-10k. Also a flywheel is much more dangerous than an engine, the entirety of energy stored is stored as kinetic energy. An engine has al little rotating mass as possible, and therefore little kinetic energya. Go back to 1st grade physics bud
@@henrygaraffa5439 Probably thinking of some motorbikes there. 11k rpm redline is fairly common, plus the engine will still be right under your nuts.
That said, flyweels are scarier.
@@henrygaraffa5439 my ninja 250 redlined at 16k
I like it.
I have a downhill mountain bike. Imagine this concept on the downhiller. You brake all the time. Could use the flywheel to boost off jumps or when it’s time for a short pedal between downhills.
I think you got something here if you refined this. Although I wonder about gyroscopic forces on the bike and how it will effect turning and stability.
That's surprisingly efficient! But I do think you should still try building a CVT some time because it would really benefit this and a lot of your other projects, you might be able to recover more like 70% of the speed. Since you have access to a CNC machine, I don't think it would be as complicated to build as you might think.
You could also go with something like a go-kart/minibike CVT "torque converter", which has the added benefit of also acting as a clutch.
Yeah, IMO he's losing massive amounts of energy to heat as the clutch slips. You really need a near instant clutch engagement to recover most of the energy.
Just use 2 hub motors connected by wire with a switch. You might need a gearing system to match loads. Ideally you want about the same kinetic energy per motor rpm, so gearing the flywheel hub to turn the wheel faster is best. But other than that the motor will draw a nice big kick of power off the line and then reduce its power draw.
So many smart people in the comments
@@jeffwells641 Same time, he could also CNC a custom flywheel to move weight towards perimeter to take advantage of angular momentum and reduce weight.
That's a nice idea. I quite like it. I imagine spinning the flywheel when going down a hill and then using it to help accelerate up the following hill again when I'm losing speed.
I was thinking of something similar except the flywheel is always engaged with one of the wheels. It would be harder to accelerate but might give an advantage thanks to the higher momentum
@@calebcoppin3497 if it was always engaged you'd just be losing energy from friction a bunch
I was waiting for him to do it, riding down the hill would be the most interesting part of this system.
@@TheKitMurkit why didn't he do it!
@@roonm90 Tom lives in Flatland (well not really but behind his house, his test stretch of lane is horizontal).
I mean, there's no point in spinning it up while pedaling. The entire idea is to recover the energy that would otherwise be wasted as heat by braking with conventional friction brakes. Instead, you're doing nearly 7 times as much work to store that energy as you would have used just to accelerate from the stop that much by pedaling, due to the 15% efficiency (a loss that isn't present in the pedal-only method).
What this _could_ potentially be used for is for storing energy while coasting downhill while maintaining speed, to then be used to continue to maintain speed on the way back up the next hill... but I think you'd need a real CVT for that. And a much better flywheel that isn't quite such a rickety, terrifying mess, and that can preferably go to _much_ higher RPM to store a whole lot more energy.
However, I think by the time you do all of that, just adding a regenerative braking system with a capacitor and either a large enough electric motor to reuse the energy, or a smaller motor driving a flywheel electronically, would be much simpler. The electronic systems would basically behave like a CVT but with a lot fewer wear parts and a lot less noise.
Also, just FYI, tire weights are designed to go on the inner surface of rims, so centrifugal force helps keep them _on._ That adhesive is in no way designed to hold them against pure shear force like that!
Finally, all that noise is also wasted energy. Not a significant quantity for the quick stop-go runs you were doing, but waiting at a stoplight or a crosswalk could see a rather large chunk of your hard-earned kinetic energy sapped away by parasitic friction effects.
Yes this is not free energy because extra effort is needed to pedal.... it appears there is a net loss because the effort to start from a normal standstill certainly looks like less then spooling up the flywheel by pedaling ...
CEO of "actually ☝️🤓"
What you'd probably actually use it for is capturing energy while going down a hill to reuse going up the next one.
@@laurenceperkins7468 would love to see him test this next
I have no idea what your talking about but I’ll research it
Your videos are truly inspiring... You try and learn. Truly a role model for young people venturing into engineering
Oh great, it's RAID season again. They must be losing money.
Yea
Bro my mind blanked for a good 10 seconds seeing your comment xD
"Wait I didn't post any comments, the video just got out?" "Or is it actually an old video?" "Wtf is going on there!?"
You got a very epic pfp btw ^^
Everybody pays protection money to the Allpowerfull Lesbian Family street gang.
@@rpyrat SPAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACEE
For more efficiency, I think you need two different gears, one for decelerating, and one for accelerating.
Really, one for high speed operation and one for low speed operation. Brake using the high speed, then the low speed. Accelerate using the low speed, then the high speed.
Exactly what I was thinking. A small system that flops over depending on which way the energy is being sent.
Transmission weight should also be "in" flywheel weight. This way no additional weight to bike. So transmission should also be spinning. Pretty interesting mechanical challenge.
That's exactly what I was thinking. The design question becomes which solution is best? A second engageable system, a gear changer, something else...
UK Guy: I found people selling steel discs on eBay.
US Guy: targets. You bought targets.
Lol
UK guy: i needed to make a plate which was pretty wasteful of material
US guy: i got this huge piece of billet to make a small washer
What is this "tar-jet" that you speak of?
Steel discs for targets? Not even
That is exactly what they are for
Thanks Tom. I'm glad to have found your channel. As a wannabe engineer, it's fun to live vicariously. This project brings to mind an idea I had long ago when I learned about angular momentum: it would be cool to design a bike with weights that ran along the spokes that you could adjust radially to affect your speed. Cheers!
this would be perfect in a descent followed by an ascent, you store the energy when descending then release it on the ascent
I would love to see how this might work in a situation where you have a downhill to uphill road segment, and see how the flywheel might assist and help propel you up the hill… by like engaging the flywheel to build up energy on the downhill segment and release that on uphill
That would also dramatically increase the efficiency since the clutch can be fully engaged and not slipping the whole time. I'm betting that's where most of the losses are.
Useful if you are in danger of going to fast downhill. Otherwise it's not going to be better than simply going as fast downhill as possible to assist with the uphill. Also it's an extra weight to cycle with.
@@daffyduck780 eh the extra weight not so much, say about 15 lb extra, not a lot on a rolling chassis situation, but you're right, speeding up going downhill is much more efficient, though if it is downhill to a flat plain then it could be very advantageous
If you used this design it would 'help' by most likely killing you. Storing enough energy to help in any way with a hill climb, even a very small percentage of what you lose in having to lift all that weight up the next hill, IF you could design a practical flywheel having the capability to do that, is a pipe dream.
The only way it would help at all is if someone installed the entire system at the top of each hill and you jettisoned the entire contraption just beyond the bottom of each hill, where it ran out of steam. Other than that it would be totally practical (NOT).
@@daffyduck780 yeah lol the energy still has to come from somewhere so only use it instead of brake on hills
An infinite CVT would enable you to minimize energy lost to friction within the clutch system.
It would be REALLY awesome to see you design a compact CVT. You would also be able to transfer more energy into the flywheel than just matching your half initial velocity magnitude of the bike.
Yes it looks like most of the energy is still being lost in the friction from initial engagement of the clutch
Aye, though CVTs have traditionally suffered when it comes to efficiency themselves.
@@jubuttib true, nothing is perfect. Although, definitly would be an improvement. The 2008 Dodge Caliber uses them and boy oh boy are they great on fuel economy when compared with similar weight and power vehicles without CVTs (see comments later below, this argument was invalid)
@@timothysands5537 Really? Interesting, I've yet to ever see a CVT car match a manual in fuel economy (beating a traditional torque converter automatic is a different thing and shouldn't be held as any kind of "win" IMO), at most matching on average due to slightly better city economy, with worse highway performance. It has been a while since I dived down into CVTs, may need to have another look.
@jubuttib oops, you're right. That is a faulty comparison when compared to an automatic transmission.
As far as the manual car goes, it has slippage in the clutch mechanism until the clutch's rpm matches the engine's flywheel rpm right? If Tom were to use something like the nuVinci hub seen on bicycles, wouldn't that be better (less frictional losses) than the clutch mechanism?
Don't quote me on this, but I also believe CVTs are still able to outperform manual transmission vehicles by taking advantage of operating in the optimal power curve (or was it hp curve? There is a difference). Engine efficiency declines as rpm climbs. CVTs can vary their gearing constantly to maintain the engine rpm as the vehicle accelerates.
Super cool! Not sure what settings you have on your fusion 360 CAM setup but if you haven’t already, adding a finish pass after the rough cutouts for all the CNC router parts would likely improve the circularity of the bores and overall accuracy. Having an aluminum sub plate vs MDF would also help with the overall rigidity and improve surface finishes. Keep it up!
Instead of a mechanical connection, combine the flywheel with two brushless motors: one motor for power and regen at the wheel, and the other on the flywheel. This will give you flexibility in the regen and allow you to recover up to about 85% KE if you can get a controller to manipulate the voltages and currents to get the most out of each motor.
then you would need two clutches. I dont see how this would help beyond reducing efficiency
@@nigelbess5168 You could clutch electrically using the Transistors you already have, which wouldn't waste additional Energie at all
So a battery basically?
This is not efficient there will be too much loss of energy. You can get an E-Bike instead but the E-Bike can't reload fast enough.
@@jantube358 On the contrary, as the comment stated, you could get up to 85% efficiency. You'd be unlikely to achieve that in practice, but it's way better than the 15% achieved with the mechanical system.
It requires quite a lot of energy to get going for standstill. KERS is more useful for storing energy from slowing down before going into a corner and then using that energy to recover momentum (or building up speed) as you are coming out of a corner.
Aka cruising
This would work for me coming home from work because the first half of that journey is downhill with breaking due to traffic lights. A lot of energy could be stored with no impact on my travel time or effort used. Then then I get to the bottom of the hill and need a little push up some rises, it would be sufficient. So it depends on the specific journey dynamics.
This would probably only make sense when going up and down hills, as you wouldn't want to go down hill too fast, but would want some assistance going up
The only problem is all the added weight, the flywheel adds 12 lbs to the bike, that’s a lot of extra weight to use to get up a hill on. Though I think it would be interesting for higher speed cruising on road bikes since you could store energy without breaking when at high speeds by letting the bike coast and then use that energy to accelerate when getting hit by a gust of headwind that would typically slow you down by quite a lot
Or in towns, where you have to stop and start a lot. That's where the biggest gains of regenerative braking are in cars as well.
@@brisingrxm6022 you need a flywheel with big diameter and weight only on the edge. Like a small bike wheel with lead "tire". Less overall weight for the same capacity.
@@jubuttib you'd probably need to use coupled motors for that to be very usable
@@michaelharris679 Probably yeah.
You could try building it inside the rear bike Hub in between the spokes. You could also then put some of these aero plastic covers over on top of the spokes, making it basically invisible and also more aero dynamic and the flywheel wouldnt have to fight against as much air as it had to before.
Im thinking of a mechanism somewhat similar to drum brakes they used to have inside of bike hubs
when you go to take off, just like a car "give it gas" or in this case... start to peddle when taking off and then use the clutch, idk what I'm talking about but I feel like that will make you go faster or push you farther.
Yep, I was thinking about this, since this is how it would be done in racing cars with regenerative braking
Good point. I think his demonstration with starting from a stop makes for an easier data point. But your right, I think his setup would do best in real world cycling after making those first couple pedals. Better yet, regen descending a hill, and using the flywheel to get up the next. Might take some skillful gear choosing to make the best of it though.
If it was a smooth, refined system you'd certainly pick up the beat way to use it in your application. But energy recovered is still the same, there are friction losses as the flywheel spins up, and friction losses as the flywheel is re engaged, so it isn't going to be great, it's only the recovered kinetic energy of your body and bike, that's not a while lot anyways.
This idea is stupid. He is only demonstrating what we already know. The flywheel would have to be MUCH heavier to be of any real use. But that would lower the overall efficiency of the bike.
@@tarstarkusz He could use a heavy weight but that still won’t produce an efficiency of more than 15%. Adding more weight would make it harder to get it going but also deliver more punch when getting going. Either way still outputs the same energy as being put in. (Of course at the 25% efficiency)
So when your normal bike is not giving you enough exercise just add a flywheel to it.
Well it's a good idea if you want to make your legs work even when your commute is usually very flat terrain, also I'm guessing it's easier to control your bike on a descent with a flywheel as normally you either wear the hell out of your brakes or embrace the madness that's going way faster than it is safe.
@@cdgonepotatoes4219 Will only work on very small hills. The flywheel wil just keep spinning faster and not really do much
@@kaptein1247 yeah... still something though
@@cdgonepotatoes4219 I doubt it would be noticeable on e serious decent where you would need to break hard for a long time. The flywheel will just get up to speed in the first few seconds and not do anything after
Seen and talked to a bike rider who used extra rubber bands on the handbrake to add resistance to peddling for training propuses!
Just like the old friction, toy cars we had in the sixties………still a good idea if it works full scale.
It would be some what dangerous...but I wonder if there is a way you could store the energy in a strong spring instead. The way garage doors do. Springs are the best at storing mechanical energy. Because they are essentially like mechanical batteries. It would make an excellent braking system for sure, because it would brake with progressively more force the longer its engaged. And if it had a locking gear system, that only released upon command, you could store that extra boost as long as you needed. It wouldn't be quite as dangerous, if the spring could be stored some how within the tubes of the bike frame itself, so they couldn't shoot out, if snapped. Its not something I could build, because I lack the tool and experience. But based upon what you made, it seems entirely possible. In essence turning your bike into a wind up toy. Except it would wind itself up while braking with a clutch. Seems like you have most of what you need for the idea done. If you modify the flywheel to wind up wire rope instead, conceal some springs safely in the frame or in a sealed add on container, and run the wire rope with welded pulleys. This concept would be much more effective. Another benefit is that you could utilize the boost whenever you'd like, from a dead stop to get you going, to help you up hard inclines, during the middle of you peddling when you're tired, or even while you are peddling at your top speed for like an rpm boost.
That floppy chain kills me
He even said “man these gears are loud”.....
I think that’s the chain about to fall off
@@jocaleb0236either way, he is loosing energy. A lot.
th-cam.com/video/GAZZ0ZaCL3k/w-d-xo.html
@@jocaleb0236 it's more likely that his diy sprockets were less than perfect, the profile matters greatly and even a slight error can cause all kinds of issues. Noise being all but guaranteed.
I feel like this would be counter productive for a couple of reasons, firstly you have to carry a heavy weight with you and that means more work done for a given distance, secondly it can lose angular momentum and work against you when you are turning while it is spinning due to the gyroscopic effect.
Why should that Mater? There are 2 spinning wheels normally why should a third one matter too much
@@meespo3354 because the road wheels weigh a fraction of the flywheel and rotate at a much lower speed.
@@meespo3354 the flywheel also makes the entire thing gyroscopic
solution? counter rotating flywheels!
@@ruthlessfish2506 i have two high speed rotating discs of metal underneath my groin wonder what could go wrong
I would imagine that the applications of this would be better in a more hilly area, to help with climbing using the declines to charge the fly wheel
Yeah it would help especially when those gear teeth would be lubed and engineered to perfectly fit each other. The gyroscopic effect of the flywheel would also improve balance
Also no since the bike is heavier and when it runs out of power its just a heavier bike
@@kajeralocse there is no gyroscope effect the way its mounted, if it was mounted horizontal it would though
It will not help with climbing. It only provides power when the flywheel is spinning faster than your speed would create. You would work harder climbing with it engaged. Wait till the down hill to use it as a brake or engaged all the way down for elec generation?
It will loose power as soon as an incline begins,
This is a great demonstration of how a flywheel conceptually works in a car
As others have said I'd like to see how the efficiency numbers change once everything is lubed up! Also I'd imagine the real world function of the flywheel would be to assist in pedaling rather than used alone, so a qualitative improvement vs no flywheel takeoff would be interesting too.
Im also curious to see that, AND I would also like to it with an additional flywheel. where there is one that is captive to the rear sprockets and wheel and a rear sprocket with additional speeds as space allows that would allow for ease of driving the rear wheel’s flywheel up in speed and the extra mass of the flywheel being attached to the rear wheel/sprocket would allow for better maintenance of momentum when cruising. I also think that in conjunction with this there should be, for the current under frame flywheel, a set of gears specific for each action of the flywheel that have the best mechanical advantage for each action. Being that the flywheel may be spun more efficiently by one gearing in order to be accelerated by the braking force, but a second gearing on the opposite side for applying the flywheels torque back into the bike’s normal gear system after a stop could prove more efficient than the current gearing that has to do the job of both accepting and returning the energy in both directions
In that a second gear that can more quickly transfer the flywheels torque would likely not have as much loss in energy
I'd like to see how it does with the flywheel used like a battery. Like how some old transit buses did with each stop having a recharge that topped it back off to 65k RPM.
Where you would gain a lot of efficiency would be to seal the flywheel inside a vacuum chamber. This is what they did on the prototype cars in LMP1 or at least I know that's what Porsche did for theirs.
@th-cam.com/video/8-r2U0k_zUU/w-d-xo.html
I could see myself charging up the wheel going down hills and using it sparingly whenever
This thing weight 5 kg!
I assume by "using it sparingly" you mean launching off a ramp into orbit after having charged up the flywheel for several years
I think another issue (besides it just not having much energy) is that it won't speed you up if you're already going faster than it is. Then it will just slow you down more. So unfortunately it can't be used like a nitro or something.
At least, not without including an extra gear shifting ability that could gear it up or down. Which would be cool, yeah. But still probably enough energy for much.
@I love you but
I love the fact, that when I read your username and then the comment, it makes perfect sense
I would really like to see this when going down a large hill.
This would be good in hilly terrain where you can charge the flywheel downhill and get an assist uphill.
th-cam.com/video/Iar5DDvk8fg/w-d-xo.html
I think it might explode from too high rpm
That won't happen too soon. It rather would shake the clutch apart before that.
@@mikegutsch5769 Did you see the assist it got from just a standstill? Imagine going uphill. You just carrying 6kg of dead weight all the time for that miniscule of boost. You are better off drilling holes in your bike for saving weight and saving energy that way.
I can see this being part of an enduro bike. When going down the hill, with gravity the energy from the rpm of the wheels is stored at the bottom of the hill, and when you start to go up, you can release it and get quite a boost to get up to speed
I see a great application for this as being able to slow someone down on a fast down hill, but accelerate it back up for when the slope changes into an uphill
I can't stop thinking on how much fatigue the chains would have to go through over an immediate transfer of force. O_O
"Speaking of raid-" *SKIP*
The segue was so smooth, though.
it was also shadow legends.
**Laughs in vanced sponsorblock**
I can never escape a raid shadow legends ad. They are everywhere.
@@jaxstax2406 I haven't seen a raid ad in ages because vanced blocks ads as well as sponsors
Is it me alone, but his clutch sounds like a ducati's dry clutch
no, i was thinking the same thing.
You're right! 😺 It's got that "coffee can full of rocks" sound to it.
Definitely. Lol
Haha, hadn't thought about that, your spot on.
3 years later and re-watching: I feel that the real application for this bike would be to ride down a hill, clutch engaged, at the bottom of the hill coast, and when you start to slow down engage the clutch to coast further. Sounds fun!
3:57 solution is to CNC the holes slightly (maybe 20 or 30 thou) undersize, then finish them with a reamer or endmill of the specific size required. Ideally that center hole would be drilled/bored on a lathe but the endmill/reamer method works too if it's done right. Cheers!
I was thinking the same thing as a simple solution. Might want to take a look at how that router is interpolating the holes, too. Simple tool path change might solve the problem…
WTF is “thou” 😭😭😭
@@Sjwatts thousandths of an inch, us machinists shorten it to "thou" because it's easier and faster
Why not just wire EDM or finish with a Jig Grinder? ;)
Yep reaming is the way to go. Buy an adjustable reamer or spend 80 bucks per size of reamer😬
Definitely seems like the application of this tech would work best on a downhill slope. You wouldn’t have to pedal to give the flywheel maximum speed because the hills potential energy is being stored in the flywheel if it’s engaged while going down.
Love the bravery of this guy to test out an experimental, self-modified, imperfect prototype bike while not wearing any safety gear whatsoever. Engineers scare me.
that balls was made of steel.
it's just a bike what's the worst that could happen
@@Not_XenoVoid The flywheel could fly off and dislodge his groin from the rest of his body.
They have a faith in machinery on par with the Adeptus Mechanicus.
He is wearing jeans and shoes.
That’s good enough right? Right?
Doesnt look effective but well done, this is how innovations are made
Raid: Shadow Legends follows me like a curse. Will I ever escape it?
You'll never escape it until someone got some sort of mental disease from raid shadow legends and sue them.
There's only one way to stop it: we'll all have to start playing it. Once the market is saturated, they can't advertise it anymore!
Raid: Shadow Legends is like corona, anyone can get it.
well, at least our lovely creator got some income for a future project or personal use...
We can just ignore that 🤣
*THERES NO ESCAPE*
When he said that the bike parts are cheap and easy availeble I really felt that.
What about a design where the moment of inertia for the bike wheel can be manually increased/decreased with weights on the spokes for example? To store energy and decrease speed you move the weights out. To recover the energy you can move the weights back to the centre.
That sounds like a mechanical nightmare
Difficult to do but interesting. 👍🏼
@@SuperUltimateLP that's where the fun begins
Hmmm
You could use some of the centrifugal force to push the weights out but pulling them back would be much harder to design.. Maybe you could use the rotation around the axle to pull a wire or something but that is a bit of a nightmere.
As I understand it moving the weights out though would cost as much speed as you would gain in your moment of inertia
@@nick11crafter maybe an electromagnet to pull them in? or maybe a hub electromagnet would cause chaos?
This concept works better on an adult tricycle. You can mount a heavy (80-100 lbs.) flywheel and use the crank to spin it up while stationary. You get a great launch from the heavy flywheel.
I once read about a man that invented a car that used this concept but with small motors to spin the flywheels as well as breaking force. Fun stuff.
Cool! Adding CVT will make it more efficient. Check scooter CVTs they're simpler than those of cars.
Tom have you done a video where you describe what kind of CNC cutter you are using with aluminum? Would you buy the same cnc system again?
Yes please!
Unless he swapped out the machine this is the original video for it, not sure he would endorse the supplier.
th-cam.com/video/d5HOg3wZxcI/w-d-xo.html
@@Zayllyaz Oh very nice. Thank you!
Supposedly the new Shapeoko CNC routers will do aluminum.
@@toastrecon A Workbee does.
Use it while going down a big hill and use it to accelerate back up the other end
yes. Ideal for those hilly countryside trips where I never want to stop when I reach the bottom each time, as I always want to use my momentum. Sadly, often there are traffic lights or a give-way at the bottom stealing my energy. A flywheel would solve this.
Be carefull with this. A rotating flywheel wants to stay in the same plane. When standing still this is no problem, it even helps your 'sur place'. But while driving, it wants to go in a straight line, decreasing maneuverability.
@@ruurdkemeling7423 watch the post credits of the video. The gyroscopic effect is apparently not too bad
This would be a great concept for those who live in a neighborhood full of hills where you would need to go up and down frequently. The flywheel could be used instead of the brakes when going downhill (for the most part), then the flywheel could be used to (somewhat) assist with going uphill, thus making the climb a touch easier.
And why dont you keep it fixed? Like the flywheel always connected to the bike wheel?
Might be more beneficial for keeping momentum (smoothing velocity) on hills rather than for stopping/starting.
Our boy Stanton: "I heard you liked spinning wheels, so I put a spinning wheel between your spinning wheels so your wheels can make the wheel spin when they spin!"
Good old xzibit or whatever his name was! Your quote made my day 😂
@@skylined5534 Glad to be of service ;)
technically it's supposed to be the wheels make the singular wheel spin when they unspin, but yeah , something like that is kinda correct too, since it has to charge up from riding as well
Spinception.
That is what I like
Braver man than me to have a home-made steel disc spinning in-between my legs near my tackle.
Cool. i did this too in 2003. My flywheel was a 26" mtb wheel with 6 guage copper wire wrapped around to evenly distribute weight. I removed the top tube and installed a split top tube for the wheel to slip thru to fit it on a mtb. I left the cassette hub with 7 speeds on it so I could really get it up to speed. So Yes I had a pair of grip shifters and an extra thumb shifter on the bars.I did not use a clutch, though my friend wanted me to do that to do "burn outs". The end result was it was too much of a workout. It did seem to help getting up a hill after running down a hill.
Haven’t heard your conclusions but mine would go something like, “In this video we learned there’s no such thing as a free lunch.”
Heavily discounted lunch can still add up over time, my friend who rides a lie-down bike would probably want such a system to help in city traffic and to store some down-hill energy for later up-hills!
Yes and the stupid long commercial for some kids game.....NO THANKS
Milton Friedman reference?
@@andreassjoberg3145 but it's additional weight!
Tho you can make it lighter with a big wheel that has most of the weight only around the edges. Like a small bike wheel with lead "tire".
Of course there is. You guys are providing it. Giving him patreon money, and YT ads plus his own ads. That is free breakfast, lunch and dinner. SUCKERS.
It seems like this would be most potentially useful in hilly terrain. Being able to capture extra energy from a downhill and have it assist you on an uphill would be a nice little boost.
Simple physical Laws Make it impossible
@@friederich66 flywheels are essentially batterys. Electric cars do the same thing, recharge while going downhill. There's no violation of physics laws here.
Behind how many Hills do you live? We alrready have e-bikes. There ist No need to *invent the wheel a second time* ;-)
@@lucascurtolo8710 and i am Not talking of batteries but of that stupid flywheel! We already have e-bikes.just hold a rotating bike-eheel andtryto tilt it, and you See what will happen: the wheel will try to move in a different orientation, it IS nearly Impossible to hold it. that is the force that holds a Bike upright.
@@friederich66 I'm not saying it's a good idea, just noting the only possible use case.
As someone else said, great to have a high speed flywheel rotating right beneath my groin.
Saying it violates physics tho is kinda crazy
This would be Nice to store energy downhill when you know you’ll have to brake down the hill.
yeah and then you can use the stored energy to go uphill crazy fast
@@ernest4696 I don’t know if crazy fast but it would help...
@@otavionascimento381 it would feel like fast because you normally don't go fast at all uphill with a bike
The main problem and reason for the inefficiency is the direct coupling. To build a system that is capable of transferring 100% of the energy to the flywheel, you need a variable speed coupling. I am not sure if that can be achieved using a hydraulic coupling, though the most efficient solution seems to be with an electric motor / generator on both the wheel and the flywheel.
Hey Tom there is this video on a simple ball CVT by “funtastyx” that could be just the simple and compact CVT you need to make this flywheel more effective than using a clutch that can slip.
The main problem with CVTs is that they are not very efficient, but they might add more efficiency because they would reduce the requirement for using the bike's brakes.
What about a Nuvinci CVT?
Maybe a Constantinesco torque converter?
@@ArchieHalliwell not true at all, there are very little efficiency losses if your belts are tight
@@ArchieHalliwell CVTs were used in some early hybrids/eco cars because their efficiency is really, really good. The problem is that they can tend to [fail/slip/underperform/lose efficiency] at high torque/speed conditions.
As in, 7000 RPMs in a car moving 2.5 tons of weight. Not at 2000 RPMs moving ~300lbs of weight. 'Course that would depend on the CVT in question and your tuning.
A perfect CVT would, by definition, be the best possible transmission in all scenarios. The only reason they aren't is slippage. The tech has and will continue to get better.
The solution I have used for not round holes on a cnc is to plunge the end mill to create a pilot hole in the center and then finish it on a drill press. Works wonders.
Here's an idea! A much more efficient way to contact the flywheel would be to use a torque converter. It's a common car part that's connects the engine shaft to the drive shaft of the transmission. It basically uses two turbines and a fluid to transfer the energy between the two drive shafts. This would not only make the system quiet but also increase its efficiency.
There’s a great thing for that, it’s called a « variomatic ».
Yeah.... stick that in the few millimeters of available space without adding a ton of weight.......
Also, a torque converter takes a lot of energy to run just by itself. It's why an identical pair of cars, one automatic, the other manual, will perform so differently. The manual will always be quicker because it takes a lot less power to spin the manual gearbox than it does to spin the torque converter. The reason cars can get away with it is because they only use it for initial acceleration; the converter locks together for a mechanical linkage at cruise speeds.
Some automatics, famously the ones Toyota uses in small 4-cylinders, are very efficient, but you can't reasonably expect a hacky home job to even approach that. So, far from _more_ efficient, my guess would be there'd barely be enough energy to even spin up the fluid, let alone the flywheel, in the low-speed braking runs he was doing there, and the efficiency would drop to very nearly zero.
An electric equivalent is a _much_ better idea, IMO. It could continue to convert braking energy into flywheel energy all the way down to a stop. The flywheel could also be enclosed in a partial vacuum for safety, noise reduction, and efficiency. A small capacitor could be used to be able to translate between quick stabs at the brakes and the slower spooling-up of the flywheel, and overall the whole system would be far more elegant, IMO.
Make it happen!
It's a big barrel oil you're trying to spin it's inefficient as hell
My full respect for all your experimenting and doing such things.
Loved the video. Some of the real world benefits I can see from this is acceleration smoothing on hills better than stopping and starting. Less smooth start help and more hill climb assist. Going downhill would enable more spin-up input energy and then engaging the flywheel would help assist in pedaling through the climb portion.
Love the whole concept and now I want to build a flywheel alternator mod for an electric bike. A switchable one so it either discharges the flywheel speed as mechanical energy or just keeps spinning to charge the battery when not pedaling.
I can't imagine there would be any real world benefit compared to using a lighter bike and using your gears effectively.
Additional Benefit:
The Rotational mass stabilises the bike even when the bike is stationary.
Your feet dont need to touch the Ground at a redlight.
Wow I didn't realize that!
What would be cool is a way to power up the flywheel while the bike is stationary. You approach the red light, use the flywheel to slow down, (getting some RPMs) pedal a bit while waiting (gaining max rpms) and then engage the flywheel to accelerate quickly when the light turns green
I'm pretty sure bikes don't work like that
www.britannica.com/video/185402/bicycle-motion#:~:text=What%20we%20do%20know%20about,mass%2C%20keeping%20the%20bike%20balanced.
@@burkejohnson4539 he's saying the gyroscopic effect of the flywheel would cause it to be stable at a stop. Not sure if this would help much, though.
That would actually be really good for cities! As you're coming up to a stop light, start sending the energy into the flywheel, and then once it's green, use the flywheel to get yourself going. The launch always takes the most amount of energy out of you so this would really help
Ummm. Or you can do what skilled cyclists do all the time. Plan your arrival at a stop light so that it is green when you arrive, avoiding braking. You might be able to simply slow or stop peddling and allow frictional losses to slow you as you approach a stop, and if well done, you wont need to come to a stop.
@@SeattlePioneer flywheel still good to avoid getting hit by busses tho
@@sebdapleb1523
My comment:
Your reply:
Sorry, I don't understand that at all. How does a flywheel help you avoid a collision with a bus while riding a bicycle?
In my cycling experience, busses are never a problem ---their drivers are skilled and patient and they keep safe distances from cyclists to avoid having to fill out all those company accident reports!
I'd rather be passed by fifty busses than one average motorist.
I'm guessing you don't do much cycling?
@@SeattlePioneer do you live in a place with busses but no bike lanes?
@@SeattlePioneer why do you write youtube replies like it's a mailthread or a bbs. it's 2022 dude, the 90s are long gone.
Flywheel Ultimate Cycling Kinetic Energy Recovery System
Got your acronym sorted
This seems like the perfect application for a CVT. With a CVT you could ramp from full speed to nearly stopped all while still putting energy into the flywheel. I would estimate you could get close to 50% efficiency this way.
Hard to fit a cat in the frame though. I was thinking the same thing.
Cvt?
@@wimsweldens6118 Continuously Variable Transmission en.wikipedia.org/wiki/Continuously_variable_transmission
@@celewign cat?
Anyway, I think it'd be interesting to see the effect of a big gyroscope in the bike's frame or in the wheels. It wouldn't want to turn in certain ways. You might be able to do gravity-defying maneuvers with one of those, mounted on a gymbal (sp?).
My thoughts too. Prolly a better arrangement would be electric drive dual flywheels, spinning in opposite directions
@@flishry You might be onto something here 🤔
@@flishry in order to turn a bike you make a small turn in the other direction just before you turn the way you want. This shifts your centre of gravity in so you don't just fly off the outside of your turn.
Any gyroscope strong enough to correct an ice slip would probably be strong enough to stop this minor corrective pre turn turn. As a result you might not fall off from ice, but any attempt to turn would throw you off the bike.
Or rotate the flywheel 90 degrees laterally or vertically.
I suppose not unsimilar to motorcycle wheels at high rpm (30+mph). Seems like a feature. I wonder if the ideal gyrocycle would behave like those gyroscopic unicycles. Then you could keep peddling while stopped at traffic lights to recharge the flywheel.
3:00 sooner or later you will need a lathe Tom. 😅
He doesn't have a lathe??
@@maskedredstonerproz never notice a lathe in any video
You should try to use this to climb a very steep hill.
One reason steep hills are hard, even with a very high gear ratio, is because it becomes more difficult to generate enough inertia to take you from one pedal stroke to the next.
With a flywheel you should be able to store the inertia to carry you from one stroke to the next without slowing down.