I absolutely adore that bike! What a fantastic thing. And such a beauty to boot. The recumbent design with its reduced aerodynamic drag opens such an interesting avenue for practical electric bikes as well.
Racing is the mother of vehicle technology. Being a welder/fabricator myself, I can see many tricks you've done to shave off weight. I'm sure you've considered aluminum. I love recumbents and I'm very impressed at the progress you've made building one. I'm a big fan of the Japanese Akira bike. Found your channel by accident, I'm a subscriber now. Keep up the great work.
@@roberthorn i found your vehicle because of this same thought. I was trying to find out if people have built essentially motorised "velomobiles" as all I see everyday on a 100km commute is big SUVs with a single person sitting in each. If a honda supercub 125cc can achieve 1.5l/100km, I wonder what the same little engine could do in a light, aerodynamic body. I wish someone tried it!
The benefits of this type of vehicle are enormous if you use electric power. You can get the drag down to less than 20% of that of a normal motorcycle, and so go 500 miles (800km) on one battery charge that would take a motorcycle of normal style 100 miles (160km) at the same speed. I know this because I built one 32 years ago and have done over 150,000km in it. You get the full benefit with electric power because the motor still has high efficiency at the much reduced load; a four-stroke petrol engine suffers a big loss of efficiency at reduced load, so an 80% load reduction might reduce the fuel consumption by less than half unless you use extremely tall gearing or reduce the size of the engine.
I remember seeing a BSA that looked just like that, in the USA. This would have been in the 70's. I distinctly remember the seat. I was probably 9-13 years old. I know I wanted one. (Two dozen and (one ZX14) motorcycle(s) later.....😄
Very cool project! Have you considered making an electric version? Batteries have come a long way in the past decade! I keep thinking that a feet-forward design would help overcome the range issues plaguing commercially available electric motorcycles, but no one seems to have tried it yet. Could be a supremely comfortable highway machine.
@@roberthorn Yeah, exhaust for one, the motor gets moved under the seat and is much smaller I even like the idea of a combination of scooter type CVT with the motor, something like what is on an tmax - CVT on one side, straight belt drive on the othe, this will make the motor last longer, be more economic overall
@@roberthorn Every type of new personal transport vehicle seems to come up short. Many look as if they're purposely trying to fail & be dorky as possible. I don't understand why its so hard to get right. Its actually easy- Step #1 Make a reverse trike like scooter 🛵 that u sit in. Instead of sitting fully upright. Like a Piaggio mp3 or Yamaha Tricity that can lean & carve corners , is fun to drive but also easy to learn to drive like a scooter. Is narrow for easy parking #2 Add a removable or partially removable aerodynamic lightweight weather enclosure and some storage room for groceries. Either behind the seat or removable saddle bags & trunk (like an adventure bike) that can attach to the frame with the weather enclosure on or off. The aerodynamic enclosure #1 greatly improves milage/efficiency #2 keeps you dry & warm, 3 wheels means safer in rain than a scooter. It could be used year round even in snow with proper winter tires. Think adventure motorcycle with motorcycle price tag ( much cheaper than car price) but with 3 wheels & removable aerodynamic enclosure that can also easily be a daily commuter. It could easily realistically get 100 mpgs but also travel at 85 mph. A Honda nc750x motorcycle for example gets 65 mpg even with horrible aerodynamics but has plenty of power. Use a similar smaller 400cc-ish engine or electric. If I could build what I have envisioned in my mind. I think I could actually sell a bunch. To everyone from teens 1st vehicle to retired people who want affordable yr round transportation. You could also make it tandem 2 seated like a scooter & still keep it somewhat small. I know a teardrop shape is the most aerodynamic and a more practical bullet shape is close behind. With saddle bags & rear compartment 2 people could ride cross country in rain/cold + handle moderate off roads at 100mpgs. My other idea for a street legal, no insurance,no registration, no license electric commuter vehicle is. A 750w mid drive velomobile. Most velomobiles look super dorky and you still get wet & cold. Except for the Trisled Aquila 3 that is a cool bullet shape. It looks like a glider without wings. There is a video titled something like solar powered electric clipper trike that is the same idea as mine. A solar powered velomobile that doubles as a sleeping pod by laying the seat flat. Except isn't as fast and doesn't look as good. Basically the same idea as his but in faster nice looking bullet shape velomobile that gets recharged by lightweight folding 📂 solar panels that store underneath or behind the seat. With a pull behind bike trailer for ebike packing trips. Heat would be an electric car seat cover and air conditioning would be a couple 12V DC peltiers that are used in portable refrigerator coolers. If you could make a cool looking bullet shaped electric velomobile that could float & be used like a canoe 🛶 or kayak able to drive directly into & out of the water. Would be amazing. I really wanna build an electric velomobile setup for a cross country road trip. It'd be like velomobile/mini RV. The dash would have room for gauges and tablet. At night when it converts into a sleeping pod. You can watch a movie on the dashboard tablet with the seat leaned back.
Very clever combination of duplex steering lower links and a single pivot top wishbone, allowing simpler steering and suspension linkages as well as low unsprung weight and lower steerIng inertia than 'normal' duplex steering. I'd never seen that combination before. Is it your own idea? If so, hats off to you! Any steering idiosyncrasies as a result of this set up?
Thanks! Yes, it was my idea. I've been told by all sorts of "Experts" that I shouldn't be able to brake while turning, since the steering axis doesn't swing forward like normal, but it doesn't misbehave at all - I can trail brake into corners just fine - it provides a lot of stability and front end traction feedback. It turns out that the slip angle works with the trail just fine without any need for the forward swing from the steering axis. That said, if the steering sweep is high enough to allow the duplex arms to "Intersect", the trail geometry degrades very badly. The steering sweep on the racer was constrained enough (20 degrees either side of center) for that not to happen.
@@roberthorn Brilliant. OEC showed pre-war that the standard Temple.duplex forks would work, but yours takes it to the next level. Any issues with bump-steer in corners?
Thanks! Nil bump steer - the steering link is both parallel and equal length to the upper arm. Used a dial test indicator to get measured bump steer at the steering link under .003 mm with the full range of suspension travel - seemed like I was tuning a formula car suspension...
0:43. I was gonna say he built a Buell before Eric Buell did. But more accurately, I'd say he built a Buell before Harley Davidson started selling them.
Spent the next year rebuilding after a fast lowside crash later that year. Then the new rear suspension was installed (With 2WS!). Entered a few more races after that, then parked it for good - great fun to ride, but too overweight/under-tired to be competitive. The next racer is under construction.
Another Burt Monroe, what a brilliant design and my brain tells me it would not only be a hoot to ride it would be safer, more economical with an outstanding centre of gravity, I can't understand 10 yrs in why I'm not seeing these everywhere, if I had the money I would want one!
I love this! One of my goals before I die is to build myself one of these also. This thing just looks so sick and slick and actually quite modern for some reason. Though I don't see the reason behind making the rear wheel be able to pivot... that just seems like another complicated moving part that's has the potential to break. I guess it's so the front wheel doesn't need as much steering but meh
Two wheel steering reduces lean angle, makes lean angle changes faster, and kills weave - 3 things that a motorcycle roadracer can benefit a lot from. It has nothing to do with reducing front steering angle - the rear wheel steers 34% in the same direction as the front - watch my "Split hub center steering" video for that. Throughout the history of motorcycle racing, every single breakthrough that increased performance was also an added complication. That said, if it isn't a racer, then there's no real need for it. I hope you get to build yours and have a lot of fun with it!
@@roberthorn Oh I didn't realize this is actually your channel, sorry for being so brash about it😅 Thanks for your insight, that does make sense and I can totally picture that now. Yeah absolutely, with my one I'd probably not opt for the rear wheel steering to simplify things. When I get to building one I will definitely let you know!
I like your bike but that vertical front wheel just makes me nervous even though it works just fine. I've built several recumbent motorcycles over the years. I never thought about racing them because all of the ones I built are street legal. Have you ever thought about building a new one using everything you've learned from the first couple?
The steering axis is 12° (The axis isn't parallel with that front end). The next recumbent racer (2WS again, with 2WD, more than twice the power, a lot less weight, and real race rubber) is under construction - should have a good update on that before the end of winter.
The next one is still under construction - most of the suspension and drive system is done - just not photogenic yet. If all goes well, the engine comes out of the donor bike (KTM 890 Duke) very soon and frame construction starts soon afterwards. The frame tubing is already here...
The last one (In the above video) was converted to two wheel steering after the above video was shot - first tested it in 2016 - last race entered was 2018. The next one is both two wheel steering and two wheel drive. Should have a brief video on how that looks and works on the bench in the next few months. Thanks for asking!
@@roberthorn its gradually coming back to me. I do recall the two wheel steering modification. I'll look forward to seeing where you go with the new bike. All the best for 2023!
Bob, try something like this: Tmax variator kit(malossi) Add a 35 Kw motor(to match the Tmax engine or something with similar specs - this based on the Tmax 530 or the Tmax 560
Id like to see a bike like that but with the steering as two sticks one on each side of me. Like the old Green Machine big wheel I had as a kid sorta..or old tank controls.Right side hand would have a roll throttle just like a motorbike. You turn right by pulling back on the right stick and forward on the left. Have to add clutch to left hand like a bike again. I think it would work....somehow.Better than having to hold your arms up in front of you to steer the bars.
It would be nicer if it has more car like controls: pedal accelerator and brake...steering wheel. He should put on retractable stabilizer wheels, and make the engine a mid-engine.
Good build idea, but since you aren't sitting any lower butt wise than Dan Gurney or that one guy with the Ducati, you might as well sit more upright and shorten your wheelbase.
Seat height is 3 inches lower and the head height is a LOT lower than the Gurney 'Gator. Otherwise, it would have been better with a shorter wheelbase, but the 2WS system added to it later (And originally designed around) made the wheelbase irrelevant.
@@roberthorn Your seat height is 15 inches? Geez... Well anyway, the reason I ask is that I'm considering my own recumbent design, but I'm also trying to balance performance with comfort, looks, and certain max dimensions that, quite frankly, affect the former and latter. Not to mention simplicity since I'm not keen on adding 2ws or 2wd... Looks a little dicey if I'm being honest, too.
Yes - 15 inches. Have fun with your design and build - glad to know others also want to do that. No need at all for 2ws or 2wd for what you're working on - my reasons for it are here: rohorn.blogspot.com/2020/12/but-why.html
@@roberthorn Heck, after reading some of your blog I think I have more questions than answers. >Why go sub-180 rear tire if presumably, all the race rubber is 180-200? >Is there any point in going wider (or skinnier) than the traditional 120 on the front? >Assuming the availability of tires wasn't an issue, do you think any change in wheel diameter is due for optimization? Bigger or smaller? >Wouldn't the rear steer make handling worse at non-countersteering speeds since it'll "crab" or maybe even want to fall down too easily or w/e? >Why are most of your videos hidden and/or with comments off? >Are you ever going to do a deep dive video explaining the design theory? >Is the 2ws and 2wd really needed or are you just doing it because of a mixture of personal challenge and pushing the limits? How much farther do you think they'll take you performance-wise compared to RWD and only front steering? >Have you considered a rear engine layout? >Is the (no offense) relatively ugly-looking suspension the only way you want to do suspension? Have you looked into Bimota or w/e they're called? I know you like Mr. Britton... >Is your rear suspension design the only way to package a good mono-shock setup? (the finalized 'Gator couldn't do it and had to settle for duals) >Are narrow designs like yours pretty much limited to 2 cylinders wide, or do you think you could squeeze a triple without it being awkward? I know Dan liked singles for narrowness, weight savings, and the flat-track sound, but I, for one, and most certainly a multi-cylinder guy out of power density practicality, smoothness, AND sound preference. Though, perhaps a turbo single wouldn't be TOO bad... Also, something I've noticed particularly in the rider's body position is that yours seems designed for racing, while the 'Gator was just incidentally good at it due to the ultra-low CG and ultralight aspect of the design. My point is, yours isn't suited for the street, but neither are current race bikes with their hunched-over position. I find it hard to shoulder check in either extreme position, but easier when reclined than hunched. Of course, upright is optimal on the street, hence why I'm interested in Gurney's layout, as well as why I currently ride (a portly and top heavy) V-strom 650 as opposed to a sport bike, and why I like Nakeds, UJMs, and Adventure bikes in general. Cruisers feel weird with forward controls; Like there's nothing to brace against... Do you get over that or even have that feeling on something like your EX500 or the Gator? Do you ever feel the need to get or have your feet UNDER you?
1) The next racer is running 120 race slicks front and rear. The thinner tire at the back won't matter due to 2WD - the RWS works a LOT better with tires designed for steering, and it'll run the same RPM as the front. Two 120 section tires will provide more drive footprint than a 180 anyway. 2) No - I'm happy with the way front tires work on the front. But testing would find out if changes would improve anything. Or not. 3) Larger diameter would make design a pain just by making everything simply bigger with no known benefit. Smaller would make design easier, but 17" race tires are what's available, so 17" it is. 4) Same direction 2WS makes countersteering far more responsive - my last racer is strangely easy to ride at very slow speeds. At those slow speeds, it initially did feel like the back wheel was trying to pass me on the inside of the turn, but that initial feeling becomes normal operational behavior after a while. 6) TH-cam has the second most toxic "Community" on the web - I have no tolerance for it. A good example is the comment section on Fortnine's recent Feet Forward video - too many stupid comments from morons (ItLl cUt YoUr HeAd oFF!! iT LoOkS GhEy! iT wIlL BrEaK yOuR BaCk oVer bUMps!! etc...). My hidden videos lack standalone context - they're mostly support for my blog. 7) The "But Why" article was supposed to be a whiteboard video with lots of hand waving, but decided to write it instead. A video might still be a good idea. 8) Physics says it is the only way motorcycles will go significantly faster. I really want to know what that's like. No, I have no performance gain predictions - lots of work to do to get there. 9)Yes - lots of reason why and why not - depends on everything else. Even thought about placing a lightweight engine behind the rear wheel - it solves a lot of design problems that way, but looks weird - I'm way beyond worrying about what looks weird anyway... 10) The next racer will be a lot more refined than the last one, but nowhere nearly as nice as what a well financed team could do with composites, 4 axis CNC, etc... I don't have that team or facilities. Or finances. Nothing about the Bimota Tesi applies to what I'm working on, even if it is cool. Oh yes - I am, indeed, quite a fan of the Britten team and their work. 11) The suspension loads shouldn't go through the lower swingarm - it is attached to the wheel by a U-joint. It could be done, but not a good idea, even if it simplifies packaging a lot. The last racer was supposed to get an exotic pullrod layout with a centralized shocks - it would have looked really cool - it would also have added a lot of work, weight, and expense. Thought about doing that with the next racer, but same thing: Work, weight, and expense. 12) I really wanted to run a Triumph Moto2 engine for lots of reasons (Love that engine...), but it is too wide in front of the drive sprocket. V engines - twins and fours, seem ideal, but the exhaust makes them all longer than I'd prefer. Was working on my own engine (Supercharged 2 stroke - VERY compact and powerful, on paper), but an engine R&D program is one step too many. Oh yes - there are LOTS of club racing classes for twins and singles with great racing rules. That isn't the case for fours- those are almost all production based, which pretty much makes sense. 13) No, mine isn't suitable for the street at all - even if it has been around the block a "Few" times. Forward controls work great and are perfectly comfortable IF you have a good backrest and ergonomics that make good use of it. I agree: without a backrest, your feet work best under you. Fun stuff - I hope that helps.
@@roberthorn i discussed this topic in a german recumbent bike chat and anyone said this would'nt work (most without practical experience) on a recumbent bike it has some advantages: lighter propulsion unit & less friction. I did some research and think that it is a matter of steering geometrics esp. the so called trail. some bikes work on this principle, allthough not in the best way i think. If i get the time and opportunity, i will try this construction by myself.
I absolutely adore that bike! What a fantastic thing. And such a beauty to boot. The recumbent design with its reduced aerodynamic drag opens such an interesting avenue for practical electric bikes as well.
Great to see this Rob! Can't believe there wasn't a word about the extremely laid-back FF riding position!
hey man im going to build one of these but electric, yours is the absolute coolest lookin one ive ever seen and i am HEAVILY inspired
Racing is the mother of vehicle technology. Being a welder/fabricator myself, I can see many tricks you've done to shave off weight. I'm sure you've considered aluminum. I love recumbents and I'm very impressed at the progress you've made building one. I'm a big fan of the Japanese Akira bike. Found your channel by accident, I'm a subscriber now. Keep up the great work.
Thanks!
Genius! Absolutely incredible! Inspirational and I don’t know anything about bikes but this makes me want to know more! Great job!
Put a nice fairing on and you'd get twice the MPG of the same motor in a upright riding position. That's the benefit of FF IMO.
Ideally, yes!
More about that here: rohorn.blogspot.com/2014/04/forward-thinking-friends.html
@@roberthorn i found your vehicle because of this same thought. I was trying to find out if people have built essentially motorised "velomobiles" as all I see everyday on a 100km commute is big SUVs with a single person sitting in each.
If a honda supercub 125cc can achieve 1.5l/100km, I wonder what the same little engine could do in a light, aerodynamic body. I wish someone tried it!
Check this out: www.velomobiel.nl/allert/Recumbent%20motorbike.htm
@@roberthorn Thank you! I had no idea someone had tried this
The benefits of this type of vehicle are enormous if you use electric power. You can get the drag down to less than 20% of that of a normal motorcycle, and so go 500 miles (800km) on one battery charge that would take a motorcycle of normal style 100 miles (160km) at the same speed. I know this because I built one 32 years ago and have done over 150,000km in it. You get the full benefit with electric power because the motor still has high efficiency at the much reduced load; a four-stroke petrol engine suffers a big loss of efficiency at reduced load, so an 80% load reduction might reduce the fuel consumption by less than half unless you use extremely tall gearing or reduce the size of the engine.
Ton's of Respect for you Robert, for the nice bike and results !
Man that is so sweet
I am looking at building a recumbent motorbike, electric though,, but I love the idea
Hey, thanks for posting this, I literally just "discovered" your work over the weekend and have been searching for everything I can.
I remember seeing a BSA that looked just like that, in the USA. This would have been in the 70's. I distinctly remember the seat. I was probably 9-13 years old. I know I wanted one. (Two dozen and (one ZX14) motorcycle(s) later.....😄
Very cool project! Have you considered making an electric version? Batteries have come a long way in the past decade! I keep thinking that a feet-forward design would help overcome the range issues plaguing commercially available electric motorcycles, but no one seems to have tried it yet. Could be a supremely comfortable highway machine.
Oh yes! Given enough money, I'd rather build an electric one for many reasons...
@@roberthorn Yeah, exhaust for one, the motor gets moved under the seat and is much smaller
I even like the idea of a combination of scooter type CVT with the motor, something like what is on an tmax - CVT on one side, straight belt drive on the othe, this will make the motor last longer, be more economic overall
@@roberthorn Every type of new personal transport vehicle seems to come up short. Many look as if they're purposely trying to fail & be dorky as possible. I don't understand why its so hard to get right. Its actually easy- Step #1 Make a reverse trike like scooter 🛵 that u sit in. Instead of sitting fully upright. Like a Piaggio mp3 or Yamaha Tricity that can lean & carve corners , is fun to drive but also easy to learn to drive like a scooter. Is narrow for easy parking #2 Add a removable or partially removable aerodynamic lightweight weather enclosure and some storage room for groceries. Either behind the seat or removable saddle bags & trunk (like an adventure bike) that can attach to the frame with the weather enclosure on or off. The aerodynamic enclosure #1 greatly improves milage/efficiency #2 keeps you dry & warm, 3 wheels means safer in rain than a scooter. It could be used year round even in snow with proper winter tires. Think adventure motorcycle with motorcycle price tag ( much cheaper than car price) but with 3 wheels & removable aerodynamic enclosure that can also easily be a daily commuter. It could easily realistically get 100 mpgs but also travel at 85 mph. A Honda nc750x motorcycle for example gets 65 mpg even with horrible aerodynamics but has plenty of power. Use a similar smaller 400cc-ish engine or electric. If I could build what I have envisioned in my mind. I think I could actually sell a bunch. To everyone from teens 1st vehicle to retired people who want affordable yr round transportation. You could also make it tandem 2 seated like a scooter & still keep it somewhat small.
I know a teardrop shape is the most aerodynamic and a more practical bullet shape is close behind. With saddle bags & rear compartment 2 people could ride cross country in rain/cold + handle moderate off roads at 100mpgs.
My other idea for a street legal, no insurance,no registration, no license electric commuter vehicle is. A 750w mid drive velomobile. Most velomobiles look super dorky and you still get wet & cold. Except for the Trisled Aquila 3 that is a cool bullet shape. It looks like a glider without wings.
There is a video titled something like solar powered electric clipper trike that is the same idea as mine. A solar powered velomobile that doubles as a sleeping pod by laying the seat flat. Except isn't as fast and doesn't look as good. Basically the same idea as his but in faster nice looking bullet shape velomobile that gets recharged by lightweight folding 📂 solar panels that store underneath or behind the seat. With a pull behind bike trailer for ebike packing trips. Heat would be an electric car seat cover and air conditioning would be a couple 12V DC peltiers that are used in portable refrigerator coolers.
If you could make a cool looking bullet shaped electric velomobile that could float & be used like a canoe 🛶 or kayak able to drive directly into & out of the water. Would be amazing.
I really wanna build an electric velomobile setup for a cross country road trip. It'd be like velomobile/mini RV. The dash would have room for gauges and tablet. At night when it converts into a sleeping pod. You can watch a movie on the dashboard tablet with the seat leaned back.
I have tried it, and it works. 500 miles (800km) on one battery charge, at normal traffic speed.
The feet forward position looks so cool
Lovely job. Very impressive work. I would love to ride something like that. Superb!👍👍👍
Really cool concept. Would've been cooler if it looked a little more like Kaneda's bike in Akira.
I miss my Recumbent ... It even had custom anti-theft parts for it like a tank shield , flame throwers and modular controls .
This bike is incredible
Very clever combination of duplex steering lower links and a single pivot top wishbone, allowing simpler steering and suspension linkages as well as low unsprung weight and lower steerIng inertia than 'normal' duplex steering. I'd never seen that combination before. Is it your own idea? If so, hats off to you! Any steering idiosyncrasies as a result of this set up?
Thanks! Yes, it was my idea.
I've been told by all sorts of "Experts" that I shouldn't be able to brake while turning, since the steering axis doesn't swing forward like normal, but it doesn't misbehave at all - I can trail brake into corners just fine - it provides a lot of stability and front end traction feedback. It turns out that the slip angle works with the trail just fine without any need for the forward swing from the steering axis.
That said, if the steering sweep is high enough to allow the duplex arms to "Intersect", the trail geometry degrades very badly. The steering sweep on the racer was constrained enough (20 degrees either side of center) for that not to happen.
@@roberthorn Brilliant. OEC showed pre-war that the standard Temple.duplex forks would work, but yours takes it to the next level. Any issues with bump-steer in corners?
Thanks!
Nil bump steer - the steering link is both parallel and equal length to the upper arm. Used a dial test indicator to get measured bump steer at the steering link under .003 mm with the full range of suspension travel - seemed like I was tuning a formula car suspension...
Hey! I've seen this bike on The Kneeslider blog years ago!
Nice going! Good to see the Rohorn back on its wheels going fast. 😉
0:43. I was gonna say he built a Buell before Eric Buell did.
But more accurately, I'd say he built a Buell before Harley Davidson started selling them.
I would love to hear what's going on with this now. Cool idea.
Thanks! It's in the St. Francis Motorcycle Museum in St. Francis, Kansas. The follow-up racer is on the bench getting a frame right now...
Holy cr*p! Love this bike!!!
What happened the next year does anyone know?? Still dont know my favourite odd ball... This is challenging the gurney alligator for top spot now
Spent the next year rebuilding after a fast lowside crash later that year. Then the new rear suspension was installed (With 2WS!). Entered a few more races after that, then parked it for good - great fun to ride, but too overweight/under-tired to be competitive. The next racer is under construction.
Hi Rob hope all's well
Another Burt Monroe, what a brilliant design and my brain tells me it would not only be a hoot to ride it would be safer, more economical with an outstanding centre of gravity, I can't understand 10 yrs in why I'm not seeing these everywhere, if I had the money I would want one!
id love to know how you made it and the breakdown of how you did it. looking to make a bike just like that.
I see you got a kaneda-esque avatar, going to build that bike too?
No, but that is a fun idea.
So I'm checking out you tube and I see Rohorn. What, heeyyy! How are you? Great job on the bike.
Great to hear from you, John - thanks!
Doing well - working on the next one...
Motorcycle gear is a big industry. The safer the bike, the less money people spwnd on gears.
👌🧐🤏The conductor conducting a philharmonic, what a sound
滅茶苦茶クールなバイク！！高い知性を感じます。
I love this! One of my goals before I die is to build myself one of these also. This thing just looks so sick and slick and actually quite modern for some reason. Though I don't see the reason behind making the rear wheel be able to pivot... that just seems like another complicated moving part that's has the potential to break. I guess it's so the front wheel doesn't need as much steering but meh
Two wheel steering reduces lean angle, makes lean angle changes faster, and kills weave - 3 things that a motorcycle roadracer can benefit a lot from. It has nothing to do with reducing front steering angle - the rear wheel steers 34% in the same direction as the front - watch my "Split hub center steering" video for that.
Throughout the history of motorcycle racing, every single breakthrough that increased performance was also an added complication.
That said, if it isn't a racer, then there's no real need for it. I hope you get to build yours and have a lot of fun with it!
@@roberthorn Oh I didn't realize this is actually your channel, sorry for being so brash about it😅
Thanks for your insight, that does make sense and I can totally picture that now.
Yeah absolutely, with my one I'd probably not opt for the rear wheel steering to simplify things. When I get to building one I will definitely let you know!
I like your bike but that vertical front wheel just makes me nervous even though it works just fine. I've built several recumbent motorcycles over the years. I never thought about racing them because all of the ones I built are street legal. Have you ever thought about building a new one using everything you've learned from the first couple?
The steering axis is 12° (The axis isn't parallel with that front end).
The next recumbent racer (2WS again, with 2WD, more than twice the power, a lot less weight, and real race rubber) is under construction - should have a good update on that before the end of winter.
That's for putting this up Robert. I recall you were building a better faster version of your FF bike, is there anymore information on that?
The next one is still under construction - most of the suspension and drive system is done - just not photogenic yet. If all goes well, the engine comes out of the donor bike (KTM 890 Duke) very soon and frame construction starts soon afterwards.
The frame tubing is already here...
@@roberthorn Is that the two wheel steering version? Was it also two wheel drive?
The last one (In the above video) was converted to two wheel steering after the above video was shot - first tested it in 2016 - last race entered was 2018. The next one is both two wheel steering and two wheel drive.
Should have a brief video on how that looks and works on the bench in the next few months. Thanks for asking!
@@roberthorn its gradually coming back to me. I do recall the two wheel steering modification. I'll look forward to seeing where you go with the new bike. All the best for 2023!
Thanks!!
Bob, try something like this:
Tmax variator kit(malossi)
Add a 35 Kw motor(to match the Tmax engine or something with similar specs - this based on the Tmax 530 or the Tmax 560
Id like to see a bike like that but with the steering as two sticks one on each side of me. Like the old Green Machine big wheel I had as a kid sorta..or old tank controls.Right side hand would have a roll throttle just like a motorbike. You turn right by pulling back on the right stick and forward on the left. Have to add clutch to left hand like a bike again. I think it would work....somehow.Better than having to hold your arms up in front of you to steer the bars.
honestly this is only way to improve motorbikes shortbase of it are now limiting how fast they can go or how fast they can stop
Does this have the rear wheel steering (or is that a similar bike)
The rear wheel steering system was installed on this bike after this video was produced.
My friend has a centre hub steering system for sale in uk complete wheel and it just needs the front swing arm and connecting rods near as damit new
That is damned cool
Very much like Dan Gurney's Alligator
That's the one most people are familiar with, which is cool, but there are a LOT of differences between the two.
Robert how much would it be to commision a copy of your motorcycle but fashion like the Akira Motorcycle?
That's a really cool idea, but I'd have to replace my day job for a year or so, plus materials and parts...
wich those bike where mainstream, like in akira, they would be so efficent. you could make them electric because recumbets are huge.
It would be nicer if it has more car like controls: pedal accelerator and brake...steering wheel. He should put on retractable stabilizer wheels, and make the engine a mid-engine.
Good build idea, but since you aren't sitting any lower butt wise than Dan Gurney or that one guy with the Ducati, you might as well sit more upright and shorten your wheelbase.
Seat height is 3 inches lower and the head height is a LOT lower than the Gurney 'Gator. Otherwise, it would have been better with a shorter wheelbase, but the 2WS system added to it later (And originally designed around) made the wheelbase irrelevant.
@@roberthorn Your seat height is 15 inches? Geez...
Well anyway, the reason I ask is that I'm considering my own recumbent design, but I'm also trying to balance performance with comfort, looks, and certain max dimensions that, quite frankly, affect the former and latter.
Not to mention simplicity since I'm not keen on adding 2ws or 2wd... Looks a little dicey if I'm being honest, too.
Yes - 15 inches.
Have fun with your design and build - glad to know others also want to do that. No need at all for 2ws or 2wd for what you're working on - my reasons for it are here:
rohorn.blogspot.com/2020/12/but-why.html
@@roberthorn Heck, after reading some of your blog I think I have more questions than answers.
>Why go sub-180 rear tire if presumably, all the race rubber is 180-200?
>Is there any point in going wider (or skinnier) than the traditional 120 on the front?
>Assuming the availability of tires wasn't an issue, do you think any change in wheel diameter is due for optimization? Bigger or smaller?
>Wouldn't the rear steer make handling worse at non-countersteering speeds since it'll "crab" or maybe even want to fall down too easily or w/e?
>Why are most of your videos hidden and/or with comments off?
>Are you ever going to do a deep dive video explaining the design theory?
>Is the 2ws and 2wd really needed or are you just doing it because of a mixture of personal challenge and pushing the limits? How much farther do you think they'll take you performance-wise compared to RWD and only front steering?
>Have you considered a rear engine layout?
>Is the (no offense) relatively ugly-looking suspension the only way you want to do suspension? Have you looked into Bimota or w/e they're called? I know you like Mr. Britton...
>Is your rear suspension design the only way to package a good mono-shock setup? (the finalized 'Gator couldn't do it and had to settle for duals)
>Are narrow designs like yours pretty much limited to 2 cylinders wide, or do you think you could squeeze a triple without it being awkward? I know Dan liked singles for narrowness, weight savings, and the flat-track sound, but I, for one, and most certainly a multi-cylinder guy out of power density practicality, smoothness, AND sound preference. Though, perhaps a turbo single wouldn't be TOO bad...
Also, something I've noticed particularly in the rider's body position is that yours seems designed for racing, while the 'Gator was just incidentally good at it due to the ultra-low CG and ultralight aspect of the design. My point is, yours isn't suited for the street, but neither are current race bikes with their hunched-over position. I find it hard to shoulder check in either extreme position, but easier when reclined than hunched. Of course, upright is optimal on the street, hence why I'm interested in Gurney's layout, as well as why I currently ride (a portly and top heavy) V-strom 650 as opposed to a sport bike, and why I like Nakeds, UJMs, and Adventure bikes in general. Cruisers feel weird with forward controls; Like there's nothing to brace against... Do you get over that or even have that feeling on something like your EX500 or the Gator? Do you ever feel the need to get or have your feet UNDER you?
1) The next racer is running 120 race slicks front and rear. The thinner tire at the back won't matter due to 2WD - the RWS works a LOT better with tires designed for steering, and it'll run the same RPM as the front. Two 120 section tires will provide more drive footprint than a 180 anyway.
2) No - I'm happy with the way front tires work on the front. But testing would find out if changes would improve anything. Or not.
3) Larger diameter would make design a pain just by making everything simply bigger with no known benefit. Smaller would make design easier, but 17" race tires are what's available, so 17" it is.
4) Same direction 2WS makes countersteering far more responsive - my last racer is strangely easy to ride at very slow speeds. At those slow speeds, it initially did feel like the back wheel was trying to pass me on the inside of the turn, but that initial feeling becomes normal operational behavior after a while.
6) TH-cam has the second most toxic "Community" on the web - I have no tolerance for it. A good example is the comment section on Fortnine's recent Feet Forward video - too many stupid comments from morons (ItLl cUt YoUr HeAd oFF!! iT LoOkS GhEy! iT wIlL BrEaK yOuR BaCk oVer bUMps!! etc...). My hidden videos lack standalone context - they're mostly support for my blog.
7) The "But Why" article was supposed to be a whiteboard video with lots of hand waving, but decided to write it instead. A video might still be a good idea.
8) Physics says it is the only way motorcycles will go significantly faster. I really want to know what that's like. No, I have no performance gain predictions - lots of work to do to get there.
9)Yes - lots of reason why and why not - depends on everything else. Even thought about placing a lightweight engine behind the rear wheel - it solves a lot of design problems that way, but looks weird - I'm way beyond worrying about what looks weird anyway...
10) The next racer will be a lot more refined than the last one, but nowhere nearly as nice as what a well financed team could do with composites, 4 axis CNC, etc... I don't have that team or facilities. Or finances. Nothing about the Bimota Tesi applies to what I'm working on, even if it is cool. Oh yes - I am, indeed, quite a fan of the Britten team and their work.
11) The suspension loads shouldn't go through the lower swingarm - it is attached to the wheel by a U-joint. It could be done, but not a good idea, even if it simplifies packaging a lot. The last racer was supposed to get an exotic pullrod layout with a centralized shocks - it would have looked really cool - it would also have added a lot of work, weight, and expense. Thought about doing that with the next racer, but same thing: Work, weight, and expense.
12) I really wanted to run a Triumph Moto2 engine for lots of reasons (Love that engine...), but it is too wide in front of the drive sprocket. V engines - twins and fours, seem ideal, but the exhaust makes them all longer than I'd prefer. Was working on my own engine (Supercharged 2 stroke - VERY compact and powerful, on paper), but an engine R&D program is one step too many. Oh yes - there are LOTS of club racing classes for twins and singles with great racing rules. That isn't the case for fours- those are almost all production based, which pretty much makes sense.
13) No, mine isn't suitable for the street at all - even if it has been around the block a "Few" times. Forward controls work great and are perfectly comfortable IF you have a good backrest and ergonomics that make good use of it. I agree: without a backrest, your feet work best under you.
Fun stuff - I hope that helps.
Sell these please so we can make Akira's bike!
金田akiraバイクは
こういうのでイイんだよ
つーかこれが答えな気がする
ステアリングの理屈が不明だが
運動性能高そうだしバンクしてる
これにキャノピースクリーンとか付ければもう完璧やないの
do frontwheel drive rearwheel steering and you'll win the race😀
That sounds too much like the infamous Joan Claybrook bike!
Seriously though, the next one is 2WS and 2WD....
@@roberthorn i discussed this topic in a german recumbent bike chat and anyone said this would'nt work (most without practical experience) on a recumbent bike it has some advantages: lighter propulsion unit & less friction. I did some research and think that it is a matter of steering geometrics esp. the so called trail. some bikes work on this principle, allthough not in the best way i think. If i get the time and opportunity, i will try this construction by myself.
Make Akira real!!🎉
The best way I know how!
0° caster angle
It does look that way, but it is 12° - the steering axis isn't parallel with the upright. The virtual pivot point is ahead of the front axle.
더럽게 노력안하는 이륜차업계에 선구자격이네
A mill in the kitchen? Bet your single Bob eah?
Married - yes, she's a saint...
Might as well go all electric.
That would have been ideal, but impossible with an extremely low budget (Under $1500.00).
@@roberthorn ahh I see :( but hey maybe one day!
I would dearly love to build the electric one in my head - thanks!