Jesus, who clicked the dislike button!? The man literally summarized studies for you and replicated them on modern racing equipment - what more do you want? Another great video by this legend! And yes, I'm also going to try this on my MTB, alas I don't have a power meter on mine. But I do on the gravel bike, so I'll try it as well and also expecting to be faster on my gravel bike due to just weight: mgh = 1/2 m v^2
Maybe I’m looking at it wrong, but since you’re measuring power at the crank it’s not a surprise that you had identical times between runs. The efficiency loss shouldn’t be changing between the crank and rear wheel, so maintaining identical pedal power would always result in the same wheel speed on that run, right? If there are efficiency losses, it would be prior to that measurement and you’re not seeing it because you are compensating for it (by trying to maintain exactly 250w). For example, if having your suspension unlocked actually took, say, 10% more energy, you were automatically outputting 10% more energy in order to get 250w measured at your feet. Overall, you were putting 10% more effort into it, but this isn't captured at the power meter. The extra output is being lost to the inefficiencies. This might explain the higher heart rate? Maybe, ideally, you would maintain the same aerobic output and then measure the wattage and speed, instead. No idea how you would do that on the trail without a VO2 mask or something… It’s like the difference between measuring crankshaft hp or wheel horsepower on a car. If you were trying to measure the efficiency changes of a car after making some driveline change, maintaining a fixed output by measuring at the wheel each time would always get you the same speed result, whereas measuring crank hp or even fuel usage is where you would actually see resulting changes. Or maybe I’m overthinking it…
I like where your head is at. Here’s me doing some overthinking as well (please correct me if I’m wrong here). If the suspension absorbs energy on the downstroke then it will return that energy on the upstroke. Some energy will be lost to friction in the shock but this amount seems to be negligible. GCN talked about something to this effect in their video regarding frame stiffness. That of course doesn’t mean it’s correct.
This is exactly it, measuring power at the pedals doesn't necessarily account for the power being lost in the suspension. There must be energy used to keep the suspension active and bobbing up and down and overcoming friction in the suspension links. This energy doesn't have to be transferred through the pedals, and you can verify this by bouncing up and down on your bike while keeping your pedals motionless, you are compressing your suspension using energy not measured by the power meter. This additional energy may be reflected in the elevated heart rate measurement he took. Its probably relatively small, mostly just to overcome the friction in the links, but if he tested with a larger travel bike with less auti-squat the motion would be more exaggerated and the power required to maintain the pogo stick effect would be higher.
@@DylanJohnsonCycling Oh, I agree, the actual difference might be negligible. Like you and appocketz say, probably the only loss is the internal friction in the spring, fluid flow, and in the suspension bearings (probably turning into heat). And maybe some internal body friction as you bob around a bit more? I was just curious from a testing methodology. Now that I think of it, I'd bet most of us here that watch your videos are like minded overthinkers. That's why we love your science based approach!
Well… the energy used to bounce the suspension in the unlocked setup would not be transferred to the pedal stroke when the suspension is locked? 🤔 During a sprint on a road bike, you push & pull hard on your handlebars, to generate more force on your pedals… Don’t you think ?
@@DylanJohnsonCycling I think you might be able to determine the energy lost into the damper by measuring the temperature rise of the damper (ideally fluid but body temperature could work) locked and unlocked. That would give you a direct measurement of how much energy is being lost into the damper
Comment from an engineering perspective: suspension systems have basically two components, a spring and a damper. A spring absorbs energy when it compresses, but then returns that energy when it expands again. A perfect spring returns all of the energy that it absorbs and air springs are pretty darn efficient. Dampers are a bit trickier, but they basically resist fast movements, which reduces vibrations (bobbing) and helps protect against bottoming out suspension. Most importantly, dampers don't return energy, but rather dissipate it as heat: this is why suspension gets hot with lots of use, ie at the end of a downhill run. To get significant energy losses through suspension, one would have to pedal in a way that results in relatively large amounts of travel movement at relatively high travel speeds. A steady 250 W up a climb, even standing, likely does not cause this suspension travel, especially with modern bikes designed specifically to mitigate this issue, but maybe an all-out sprint with a very uneven pedal stroke (difficult to reproduce and characterize) could result in noticeable losses.
Yeah thats why Im getting a chuckle about people saying "250! Thats too low!" "Its needs to be 400!" Frankly loss of power due to loss of traction will be a bigger concern for a larger number of cyclists.
I am not an engineer and just trying to understand. The spring is absorbing energy that you're putting into the bike, but when it expands giving back that energy surely that's then energy that isn't being transferred to the drive train? I get that energy doesn't just disappear, but I don't get how it then goes through the bike to propel you forward. I'm confused but happy to accept the science.
@@ellismccoy the energy ‘returning to the bike’ during pedaling is acting normal to the tire contact patch and that line of action is vertical and not horizontal. This the restoring force does not propel the rider forward. The energy is lost in the form of convective heat transfer from the shock to ambient air.
@@andyjonathan2486 the question was about a spring, not a shock. Also the force vector is not vertical, since a) the contact is slightly but significantly depressed into the ground b) bigger obstacles are approached and dispatched from with a horizontal component. If you want to understand how the spring suspension without a shock works, imagine riding pumptrack without pedaling
Comment from another engineer- power is being measured at the crank and transferred to the rear wheel via a chain. Neither the front suspension fork nor rear suspension mechanism have any influence on the drive train efficiency so of course Dylan produced the same time up the climb with the same power. The studies which include vo2 measurements are more interesting/ relevant but without reading and analysing i would not like to comment on their findings.
I have done the same test on an SB100. Power within 2W on every lap, and no discernible change in time. This was on an 8min smooth dirt road climb at 305W. I saw 1-2sec difference between runs. I also tested my gravel bike with 40mm slicks, and got 20sec faster… which, doing the math, is exactly what I should expect from the weight alone, so on smooth dirt a 2.4 Aspen at 21psi seems to be just as fast as a 32psi 40mm slick, at least for me.
Id love to see a comparison between say an SB 100 and SB 150. Or something similar. Obviously a bunch of elements youd need to control for (differing Geo, kinematics, weight etc)
@@brianrhamilton for sure: riding a pump track is a great example. But pedaling up a smooth climb, seated? My muscles aren’t going to move any more or less if the suspension wiggles a little bit. It still feels better to climb locked out, so for long, smooth climbs (like at Shenandoah), I lock it out. But I’m not worried about hitting the lock for a quick climb, since any inefficiency is apparently in the noise.
@@filmaynard It’s not in the noise, it’s just not being measured in these studies because it’s very difficult to do (not because it is small, just difficult).
@@filmaynard yeah Im not understanding Brians comment. There no were else for power to come from in a significant amount. Even on a non smooth climb and any where else youd use a lockout any "pumping" would be so minimal as to not call it pumping.
I'd be willing to bet that the seated/standing efficiency loss would be a lot greater on long-travel bikes, which is where Flight Attendant seems to live. I have a 115 mm and a 160 mm travel bike. Both feel nearly identical when seated, but the 115 mm bike is way more efficient when standing. I'd love to have a power meter to test this with, though.
@@TheDavidjakeson same thing I’m about to ask, the Flight attendant, but I think the big difference of Flight attendant is, it has sensor that respond at the speed of 5 nano second(just heard it, don’t quote me), so it’s not completely lockout or open, so it keeps sensing to the type of terrain and respond to the most appropriate suspension setting.
Measuring power at the crank is the reason why the times are all the same for the same power reading. The loss of efficiency occurs before the crank. If you think of the forces acting on the crank, you have the force from leg, and the reactions of the supports. Remove some of that support (ie add suspension with damping instead of a rigid platform) and you need a little extra leg force to get the same crank power. Hence HR is a little higher for the same crank power.
@@johnschmitt3083 of course it is measuring watts, at the crank. I'm saying that there is an inefficiency from leg to crank. If you pump your suspension up and down but don't pedal it will read 0 watts. So does that mean the suspension pumping doesn't take any effort or energy?
I love some healthy debate and I’ll admit that I’m not an engineer, my degree and expertise is in exercise science, so I could be completely off base here. Here is me doing some thinking on this but correct me if I’m wrong. If force is lost to the suspension on the down stroke when it’s compressed then the suspension returns it on the upstroke when it extends. GCN did a video addressing this regarding frame stiffness (doesn’t mean they’re right of course). Some energy will be lost to friction in the shock but it seems as though that amount is negligible. If what you’re saying is true, and I’m not saying here that it isn’t, that would mean that crank based power meters are inaccurate when your suspension is open.
@@DylanJohnsonCycling No, gas compression cycles are not reversible. Its a basic tenet of thermodynamics. i.e. if you do work (physics 'work') on a gas by compression, you will have losses. This is what other commentator referred to becasue those losses manifest as heat (although these are also friction losses causing the heat). If you want to nerd out you can look up carnot cycle and carnot efficiency. Now... what those losses are as a percentage of your ftp... is likely marginal. So, for you dylan, your test was too short. In a 4 hr marathon those fractions of % may be 10m, 50m...and for you is that a podium? For me I dont race, so im going to leave the lock off.
That is interesting for sure. I wonder what type of PM would capture that more. Would a pedal based meter be more accurate in that instance? My thinking being that in your pedal stroke, your power would be going to both the crank and the suspension, so would be more representative of the total power your body is producing, vs. what is getting through to the cranks.
The commenters below that stated your power meter measures the power into your chain ring, effectively, and then with a little loss to your chain, cassette and then the wheels got it right. A given power will give you an equivalent speed independent of energy lost in the suspension. Many of us know that energy is power multiplied by time. But energy is also force multiplied by distance - called work in our high school physics class. As the pedals turn, we apply a force at the top of the pedal stroke down the distance to the bottom of the pedal stroke. This becomes the power you see in the power meter. But, with the bike bobbing up and down from an open suspension, your leg has to apply force over the distance of the pedal stroke plus the distance of the suspension bobbing up and down. The power meter only measures the power going into the pedal stroke, not the power pushing the suspension. An obvious illustration of this concept is going down a steep, bumpy decent at high speed without pedaling but standing. You get to the bottom and your heart is racing, yet the power measured on the power meter was zero. That unmeasured power is similar to the power wasted pedaling with the suspension open (standing up) and not being captured in the power meter.
Well put, and as mentioned would also be reflected in an elevated HR vs other efforts.. I think this would be much more evident at efforts greater than 400w that really get the bike bobbing as well.
I couldn't put it in words as you did. Thank you. I didn't know how to explain that the power meter doesn't include the power responsible for the suspension bob.
I believe the open suspension absorbs pedaling energy meaning that 250W on open will be more exhausting than 250w on closed. This explains the difference in HR.
3 BPM is too marginal to draw that conclusion. A change in breathing, temperature, taking a drink mid-climb or even just before the ride, and most obviously fatigue for sets 2,4,6 over 1,3,5 can all explain a 3 bpm heart rate variability
Well, the studies disagree, since they measured metabolic energy and didn't find a difference there. The 4 bpm difference can easily be explained by him doing the closed runs first, it's well known that heart rate for the same power output can rise over time.
While those 3 BPM are not solid proof. I think we can prove it by logic and math: Doing the same 250 W and having a bobbing suspension means your body is producing both 250W to spin the cranks AND to move the suspension (which absorbs energy with the dampers generating heat). The power measurement is assuming everything is fixed and all the force is going into turning the crank in circles. However your BB is going up and down and that additional movement accounts for watts being 'lost' and not calculated by the power meter. The PM is thinking you're spinning circles when in reality you're spinning and moving the whole system up and down too, but it doesn't know that.
By swapping out rear tires I was able to close most of the gap from my xc hard tail race bike to my enduro FS bike. There are literally tens of watts between the fastest and slowest tires by rolling resistance and most of the rolling resistance comes from the rear tire.
Great video, I think it does miss out on one major use of lockout which is that (I think) locked out suspension makes it much easier to sprint, especially from a low starting speed. It might or might not be more efficient, but in shorter XC and short track races, sometimes you need to just get more power out when you get slowed down either out of corner or technical section, I’d argue the benefit to sprinting and the frequency of short little sprints in an XC race is the most important part of having a lockout (course dependent of course). Would be interesting to see sprinting from stopped with lockout and without, and if the lockout allows the rider to accelerate more quickly
Looking at your HR when standing, it's clear that standing-open cost more metabolically than standing-lockedout. Even though their 2 avg times were equal, but over the course of a longer effort (multi hours), would they still remain equal? I doubt it. Metabolic cost takes a while to manifest itself, especially toward the end of a long race. It's not all about mechanical efficiency. Both mechanical and metabolic efficiency count. I would say your experiment is interesting for 3-min efforts, but I would not extrapolate it to real world racing just yet, especially if that race is a long one.
Are mechanical and metabolic efficiency not directly proportional to one another? At least if metabolic efficiency changes and all other factors remain the same, mechanical efficiency should drop.
since making my comment here, I have learned something about (crank based or pedal based) powermeter behavior that makes Dylan's experiment invalid. These powermeters do not take into account the vertical bobbing movement of the bottom bracket when the bike is bobbing up and down. The crank powermeter can only measure power exactly at the crank, but it cannot account for the power required by a bobbing bottom bracket. Crank based powermeters work great for a road bike because the bottom bracket is not bobbing, not so much for full suspension. So, let's say a person puts out 250w on a rigid bike, and that same person puts out 250w on the full suspension bike, well now we know that 250w on the full suspension actually requires more then 250w because the powermeter fails to account for bobbing suspension. This would explain why Dylan's HR is ALWAYS HIGHER in the OPEN/STANDING mode even though he's keeping power output at the "same 250w", but he is actually producing MORE then 250w in the "OPEN" mode, that the crank based powermeter has failed to account for. The thing to understand here is that suspension act to dissipate energy, and that energy is dissipated in the form of heat. This is why shock fluid heats up when suspension travels. And unless you can account for this loss of energy in your measurement,.. then you're not measuring accurately, and in the case of Dylan's experiment, he is actually under-measuring power when the bike is bobbing in open suspension mode.
@@danielfeary I don't think so, his exercise duration is not long enough to be causing cardiac drift. Anyway, I have posted my follow up comment about crank based powermeter behavior and how his experiment is invalid.
@@jacco2952 Good question. I can't recall, but read somewhere that mechanical and metabolic efficiency are not the same thing. Mechanical efficiency doesn't change much with training, and further more, a pro and an amateur have pretty much the same mechanical efficiency. The reason for this is, I believe, mechnical efficiency depends on the construction of your physical anatomy. For example, blacks have high calf insertion along their leg, and this allow them to run with good mechanics. Asians and whites don't have this high insertion. Now, this doesn't mean a black person will automatically can run faster than a white or Asian, because that white or Asian could train harder and improve their metabolic efficiency (because metabolic efficiency is more trainable than mechanical) and still run faster than the black person. Anyway, since making my orginal comment, I have learned that Dylan's experiment may be invalid after all. See my follow up post above as to why his experiment is invalid.
On my 160mm bike, I notice that climbing smooth trails is just more comfortable with the suspension stiffened up. When I had an XC race bike with 65mm rear travel, I left the shock fully open all the time and it felt great.
There is another reason to reach for that lockout the people often miss: jumps and pump tracks! Having stiff suspension is great for smooth jumps and pump tracks as they allow you to pump transitions way easier.
Dylan, thanks, this was very interesting and helpful. For me the biggest consideration when it comes to the hardtail is not weight but cost. Decent full sus bikes are simply so expensive in comparison. Thanks for your excellent research and informative videos.
Excellent video. A couple of things on which I'd like to hear your reaction. 1) Although I can't find the references, I remember some studies suggesting that loss of energy occurs more because of side-to-side compliance than bobbing. Modern rear suspension has gotten very good at reducing side-to-side compliance, but it might be that be that wear in the bearings could give the efficiency advantage to a hardtail for the many riders who aren't going to have the bike's rear suspension rebuilt very often. 2) A long time ago I raced on a bike with a Fox smart fork, and the fork did a good job of responding only to terrain and not to rider inputs. I never really felt that it improved my riding efficiency overall, but I did feel it was a significant aid in maintaining balance when standing up for a sudden surge, like when the trail widens briefly and you need to get around a slower rider really fast. Pretty narrow application, but it did feel like a significant benefit.
I doubt the side to side play from bearings would have a ton of negative impact. The Nicolai G1 with EXT Storia rear shock uses spherical bearings on the shock mounts to prevent the shock from "stictioning" in turns are the frame etc flex.
I mostly use the lockout out of the saddle. Often after a long grind on the saddle you find a stretch of fine road or less steep gravel and going out of the saddle can be a relief by changing muscle actuation/stress. When out of the saddle the bike definitely bob a lot and does not look to accelerate as well on each pedal stroke. I would be curious of a sprint shoutout.
You just gotta learn how much weight to put on the fork. There is definitely a fine line. I can have my 100mm wide open and be standing and stroking hard and no bob.
Been riding my FS xc/travel bike on both pavement, XC, and trail terrains fully open for years. I experimented with the complete lockout a few times on the same routes - well, no difference - same effort, same time... So yeah, I don't even bother locking the shock or fork ever! This is a great video/information which confirms what I felt and thought all these years. Thank you for all the testing and data!
This makes a lot of sense, and also shows that new products like Flight Attendant are probably a waste of money. However, one thing not mentioned here is that on bigger bikes in particular, locking out the rear suspension on long steep climbs will keep the rear end of the bike up higher, which makes it feel like you aren't climbing something as steep, keeps the seat angle nice and steep, and helps avoid that slipping off the back of the saddle feeling. That may not be measurably faster, but is more comfortable.
Get yourself a new geo machine! Lol But in all seriousness suspension plushiness is set by the spring rate and I suspect most people will have a lesser travel bike set up firmer as you need to to have the same sag ratio.
@@tylerbruce5731 always down for a new bike, but I just built a Spire up. So although the right number of bikes is N+1, gotta wait a bit more for another, and aren't many bikes more new school than that. I can definitely feel the geo difference on big climbs with the lockout, although I only use it on paved or fire road sections, unless I forget to unlock it.
@@adanielweaver well the Spire is a new Geo machine. Looks nice, congrats! I keep thinking I want a Spur but I am really unsure. I like the lightness compared to my Pole and Nicolai but I have a feeling I would quickly regret the lesser travel.
One quick note on doing these kind of tests. If you're comparing 2 (or 4) things, alternate them as you go. If you do 2 runs of X, then 2 runs of Y, then 2 more X, then 2 more Y, you'll (mostly) account for things like HR drift and condition changes.
The thing I get from locking out is the feeling, when I stand with suspensions open I feel it messes up with my posture and movement... Kind of like it makes me lose coordination since the compression and my up and down motion just don't exactly match, if it makes any sense. So when I stand I'd rather lock them except on really steep slopes where I stand really low on the bike and I don't really move up and down that much... But when it is faster and less steep I feel I coordinate better without the pumping motion of suspensions
Really interesting stuff. I have a 40k mostly hard gravel loop with 300M of climbing which I've done multiple times both with and without locked out suspension, and with a great deal of standing. I have to say it feels just as efficient to me, regardless of the settings, which is why I usually leave it in "trail" half way between the two. One thing I'll take away from this is I've noticed my tyre pressure can stand in for suspension, so I'll be using higher pressures, and not locking the suspension on road surfaces from now on. A final note is that I've noticed excessive localised muscle fatigue with fully open suspension, which I believe is due to taxing unusual muscles at the bottom of the 'bounce', this bounce of course depends highly on the rider's weight, and suspension travel, but I believe if done enough, could slow you down.
As a science and data geek I appreciate your approach and contribution to the conversation. More of this critical analysis and evidence approach is needed in all aspects of our lives. Keep up the great work! Subscribed.
Another great video. Just what I wanted to hear. My hardtail has a non-remote lever and I'm always forgetting to switch the suspension back on. I can now just leave it alone knowing it's not slowing me down on the climbs.
So I've now watched several videos repeating similar testing conditions. Primarily using a power meter to match power for every run. Which I believe is ultimately the deciding factor. When riding xc trails or on road the difference between the suspension open or closed is negligible, which if you're an xc racer might be the reason for you to choose no lockout. However from trail riding experience I can say definitively that having my bike locked out has made a huge difference. On my Scott Genius, going from 150mm of travel to maybe 20mm when locked out there is a significant difference in the amount of effort I have to use when putting the power down coming out of a turn or if I have a fouled climb that I have to peddle out of. The same difference was noticed when I went from being over biked with a Spec Enduro with 170/180mm travel to the Genius with 150/150 or 120/120 in traction, or 20/20 when locked. Riding with the same groups I was by far the slowest on the Enduro to being one of the faster on the Genius. While the Enduro is a slight bit slacker, the Genius is also in the Enduro class with similar geometry. While I can agree maybe part of this is a mental boost, that mental boost is because it very much feels easier to peddle. Riding the same trails unlocked compared to locked I will put down much more effort with more travel. The other thing I notice about these test is that to get enough data you have to run a significant amount of runs. Given that you have to do these on the same day to prevent variables such as weather and hydration, somewhat forcing you to do short segments on simpler courses, making the difference in effort harder to measure. Or you have to risk different environmental conditions affecting the results if you were to try to do longer segments on different days. If lockouts didn't make a difference, they likely wouldn't exist on almost every bike. While remote switches are less common, is there a shock front or rear that doesn't have a switch of some sort?
It could be that the power meter is not capturing your exertion, since the meter is measuring the power through the pedals, not the energy expended bobbing the suspension. Bobbing the suspension comes from the feedback from the ground and other parts of your body, like your arms. If there was a way of capturing the totality of energy expended in your whole body, the answer might be different.
It's mostly the pedalling. The power meter is calculating the force X the RPM , but you're also moving the whole system up and down. So some of the energy is going into moving the system (bb) up and down and the rest into rotating the crank , but the power meter doesn't know that. It assumes you're just spinning circles so same wattage with bobbing suspension is actually more work in reality.
Exactly, pedalling with suspension open you have to add the force needed to compress it to the equation, the damper is working to remove that energy from the system. That force isn't measured by a power meter but you will be working harder to output the same watts.
Timely video since I have been riding a single speed full suspension MTB lately faster than the hardtail I was using previously. The rolling terrain around here make using a lockout a hassle since most climbs are only 30 seconds long.
Wow! I've been one of those constantly locking/unlocking with most climbs/descents. And, I'm definitely guilty of frequently going for the hardtail over the FS XC bike because I think it's going to be more efficient (even though I know I'm sacrificing some on descents). I'm going to minimize all that. BTW, I'm guessing this also translates choosing my slacker 120mm FS bike vs the twitchier 100 mm bike. As always, thanks for the brain food!
Oh, there's an interesting idea here, is there any literature comparing geometry @DylanJohnson? Would be interesting to check how true it is that a steeper seat tube angle improves pedalling efficiency, or that a slacker head tube angle is worse for climbing or tight tracks.
@@AlejandroGarciaIglesias an easy way to do something like this is get a Canyon Strive where you can switch the geo and travel in an instance. I had one and it taught me a lot about geo and kinematics.
Great stuff as always. Not completely parallel, but there’s a reason cars have full suspension and softer pneumatic tires. An additional important point: I would think running open, especially over longer durations and rougher terrain, would substantially reduce muscle fatigue from impacts/vibrations. P.S. Your research makes me want some suspension on my road and gravel racing bikes for long stages.
Great video Dylan. I have always preferred a lockout and I knew that it probably wasn't much different in efficiency but it does give a psychological advantage when you are standing in sprinting. The main advantage I have found is that I can run my suspension softer but still have a good pedaling platform for smooth terrain. I probably won't worry about the lock out as much anymore. It really makes you think about these new suspension technology like Fox live valve and also the SRAM flight attendant and how they are pretty much a big waste of money.
Rear lockout does help keep the cranks a bit higher thereby helping mitigate pedal strikes and steepening the seat tube angle for a slightly better climbing position.
What about sprint efficiency without and with lockout? Maybe higher power output and different pedaling technique would show better difference and why it might or might not be wise to lock suspension in short uphill or for sprint.
I still think that it has an effect on your body. I don't have scientific research or evidence to back it up, but if you test this up using the same power with the same bike (weight), the difference is gonna be negligible, since power in the simplest form is actually times x how far you move from point A to B. But your hr and rpe will be different. I also think higher power will probably gets you more different outcomes.
@@cesraihandary I think producing 250 watts on the pedals might be easier for the body with locked suspension than with open, so one can't do any meaningful test by keeping power at the pedsl equal. You would need to keep your body effort equal and that is pretty much impossible except in one way: try all out best effort and do this for a while on different days so you are fresh when you do the tests. Then after a while from your best time it should become obvious if 1 option gets you to the top for example 10% faster on average, or if they are always so close that there is no difference.
Funny you posted this video now. I too was fiddling with that this weekend. My fancy bike has been sitting around for awhile. I used it after airing up the fork and tires. I had inadvertently left my shock alone as it felt fine in my neighborhood. I went riding Saturday at my local trails ( flat with roots and quick three pedal accelerations). unlocked fork/ shock as per normal and rode. Rear shock only had 75 psi and was bobbing every pedal stroke so turned on the lockout to stop this. Sunday after airing up the shock to 140 psi, bobbing was less and felt better unlocked. I was a bit faster on the gang ride I was in on Sunday . With the correct pressure, the lockout on my shock is solid (like a hardtail). I had Risse racing revalve it last year to this spec. All I can say is, If the rear isn't spinning under power, and is fully solid when locked, It's a win/ win.
Awesome, thank you! I was thinking of using my full suspension to commute to work beings that I recently got rid of my road bike when I moved to Norway. Wanted to make sure I would be mentally okay with riding my bike to work before getting something more appropriate for commuting.
I have an XC race bike, and I have removed my lockout prior to this. I just find pedaling with the suspension open, whether it's on trail or on pavement is more comfortable. The more comfortable I am, and the less my hips bounce around, the more smooth power I can deliver, and I actually "feel" faster and more comfortable pedaling seated w/open suspension than locked.
So glad you did this video, I've been debating for months about whether to put the lockout system back in place on my bike but I didn't want to deal with the extra wires and annoying bob in the locked out position. Since I'm not losing any time anyway that seals the deal, less clutter and things for my brain to think about, just ride.
Dude, this was so good. Tho I find it super counter intuitive, bc a) it feels soooo much slower when you're bobbing around, and b) surely there are dampening/suspension losses!!! I'm never bothered with 250 W to lock it out or not... it's more when I'm out of the saddle, doing 400+ W up something steep, or sprinting. You think it's the same story? The bob would be really annoying doing these efforts and I would think def slower (or does just mean I don't pedal smoothly). Still, definitely useful info and I won't sweat it as much going forward - thanks!
This is my thought as well - 250w probably isn't really activating the suspension a ton, I would be interested in seeing a similar test as you mention over 400w, that really gets the bike squishing. I believe it's very possible that there's no meaningful loss or inefficiency, but I think this is more-so where a difference may be if it does exist (vs lower watts).
Great video man. I almost always leave my bike open and I've always thought it worked this way, but you've given me some data now. Thanks. I do like to use a lockout (or firmer mode) in some situations because it feels nicer: some steep climbs let the rear suspension sag more, and it feels like I'm pedaling a go-kart. And when you're going really fast (say start of an XC race) the kinetic energy is so high that the bobbing is more extreme, which constantly changes the geometry of your bike, which is annoying.
Thanks for this vid! Bought a CTY 2.1 as a hybrid bike for mostly trail riding. Upon buying it I found it only has pre-load knobs, and no lockout and was getting a bit of buyer's remorse. I think I'll still hold onto the bike anyways since I quite enjoy the feel of it and already installed plenty of gear, but I'll also keep my eyes open for any other bikes that catch my fancy.
Theory - on a relatively smooth surface, locking the dampers simply transfers the load stresses fully to the tyres, so the total system suspension and efficiency is unchanged. Instead of ‘vertical’ power being absorbed by oil or air in forks, that same energy is absorbed by rubber and air in tyres. 🤔
But the tire compresses and rebounds sort of uncontrollably and doesn't 'absorb' as much energy as a compression/rebound circuit. There's not (as much) resistance in the 'travel' of the tire , it's more of a basic spring. I think even with open suspension those watts converted to heat in the damper are pretty negligible unless you're sprinting out of the saddle on a long travel enduro bike for example.
Pinkbike tested this and they found the lockout definitely helps, but it's just a small amount in the best of scenarios. From personal experience, not long ago I rode with a Fox shock that had its damper blown and found it near to impossible to keep up with the group I usually ride with, sent the shock to service and got the lockout back to a working state, now I can keep up with the usual effort. I don't have power numbers but definitely made a noticeable difference.
This video is interesting. I had my lockout lever broken this summer so I was riding around without one for a couple weeks. To my own surprise I had PB times around my local trails. My bike is a Scott Spark RC.
What matter most when it comes to suspension is kinematics and geometry. Many people associate longer travel with poorer pedalling performance. That may largely be due to the fact that historically longer travel bikes (eg Downhill rigs) often have poor pedalling geometry. And may also have poor pedalling kinematics. My first full suspension mtb was a Canton Strive which allows you to switch the geo and kinematics instantly. It did a lot for my understanding of these. That allowed me to understand the whole longer slacker concept as well and now I ride a Pole Evolink and a Nicolai G1.
Awesome video I was deciding on hard tail or full sus and I think these days with the newer tech and easy lock out feature I will go for it as a full sus even though it may be a little slower on climbs when going for those few seconds the sheer comfort and efficiency of a full sus makes everything a lot nicer and comfortable and more forgiving.
Great video. I own a Pivot Mach 4 SL... I originally was going to get a lockout installed for the rear, but after riding it through a couple tough training sessions and races I leave it at the mid-setting near 100% of the time. As long as a bike has hyper-efficient suspension kinematics, I won't be thinking about touching the lockout.
Such an interesting video. One thing that you mentioned at the end of the video always occurs to me. Feel. Yes it may not be any faster on paper, but if it feels slower or even uncomfortable, then thats not ideal.
Very interesting! The immediate next question for me that jumps out after learning this, is if there are any disceranable efficiency differences between the "trail mode" and "fully open mode" of most typical 3 position suspension setups !?? Based on the evidence provided here, I would conjecture probably not, and therefore would be more inclined to just always keep it in open mode for the more plush feeling, and have less to think about on the trail. But would love to see this tested the same way as in this video
Another fantastic proper-science driven video (and rather validating as I've not felt full lockouts increased pedaling efficiency). However, I do find the compression lever, only on the rear, useful to maintain better climbing geometry. Using "trail mode" on most shocks on prolonged steep/technical climbs on my long-travel enduro bike (160mm+) because of their inherently slack (sub-64/65 degrees or so) head angles. As it has quite a lot of sag (and I'm running a coil), I can reap the benefits of a steeper head angle without drawbacks of a loss of traction.
The problem isnt the head angle its the seat angle. I have a Nicolai G1 which climbs great and its 17+kg with a 62 head angle. But it also has a steep seat angle.
@@tylerbruce5731 Yes, agreed. Should have said both HTA and STA but oversimplified it down to just HA. Should have also add that as I ride a size XL bike with lots of exposed post, the effective STA is even slacker so the compression lever also helps there.
I'd love to see a similar test repeated by somebody who might be a less experienced rider or somebody with a choppier pedal-stroke. I'd imagine you're relatively smooth in terms of power application Dylan.
verry interesting information! Im an XC racer, I rided my HT bike without the lockout knob and cables (weight saving), I needed some adaptation time to all-time open suspension feeling, but very quickly it become natural to ride like that. Now I ride a FS bike, and the most difference I notice is on the longer techy DH sections, where the FS bike let me rest a bit more than a HT bike (hearth rate manage to drop lower due to less body work needed). but I still keep the lockout on the FS :) it come handy on the asphalt sections
Fantastic news! My road/gravel/bikepacking bike is a Specialized Diverge and evidently I needn't worry about any efficiency loss due to the Future Shock,. Meanwhile, my MTB is an old Scott Strike G zero from 2002 which doesn't have any lockout option on either front or rear but I don't have to worry about that either? - Great!
interesting, especially the standing data. was not expecting that standing on a shifting platform would be just as efficient as standing on a stable platform
I think you need to try a new fork with 44mm offset. That has to be the key. In all seriousness regarding inclines, pure system weight (rider and bike) is the biggest factor to consider, additionally, tire rolling resistance (carcass, tread design, compound, pressure and speed of rotation) and of course “aerodynamic drag” on faster moving incline sections. This was an interesting vid that got me thinking about the suspension , we have all been there in the mountains riding up rocky sections on a hardtail vs a decent pedal platform FS, and felt the bike suspension allow the tire to come up and over the obstacle vs a Hardtail that has to push your rider weight(seated) up and over the obstacle- Hardtail - its doing more “work” but typically can be 2-4 lbs lighter bike in the race XC scene. Its very interesting.
Oh man, you're doing testing now! Very interesting results. Might I suggest you do another test and expand on a video you made regarding clipless and flat pedals!
very interesting! excellent video as always. When I use the lockout, I often forget to switch it back when I hit the bumpy stuff again. Foregoing the lockout will give me one less thing to think about. I can usually only think about one thing at a time anyway, so this is awesome for me.
As owner also of a RKT9RDO with the 34-120 fork, I leave the shock and fork in the middle position on paved roads and all the way open on dirt roads and tracks. I think the added comfort makes you quicker at the long run. But than again, Niner has an excellent pedal platform, could be different for other kinimatics on other bikes.
Same with my Fox step cast forks. When grit gets down in the lockout mechanism it jams up (usually at the worst time). Got tired of F-ing with it so I might as well get rid of the useless lever and cables all together.
Did a mountain bike race recently on a rooty course on my hardtail. Definitely was significantly slower on downhills. The roots bounce you more and act as a brake every time they send you up instead of down. Very frustrating to watch people disappear away each downhill.
Great video! Measuring power at the pedals eliminates the effect of suspension movement and any losses there. Power expended is all that matters! What’s amazing is how you hit the same power on each run. I would have expected variation there. I think I’ll remove my lockout and save some weight!
Cool data, thanks! I did a lot of tests between my XC FS mountain bike and my "gravel bike" and to make the story short, I ended up selling the second. The terrain where I live is extremely steep. I'm gonna do some testing with my bike and see how it goes.
Wow, the psychological effect is huge then (like it is with clipless pedals - see Dylan's earlier video). I came out of winter 19/20 and the first lockdown completely detrained and rode a full sus with a missing lockout lever and got badly dropped by my brother-in-law on every climb. It was my excuse, he was on a hardtail. Next time just a few weeks later I came back with a working lockout and flipped it around, dropping him on every climb. I did no cycling in between (nor running or other material exercise). I do believe your results (given the other papers too) so it must just have been psychological. I believed I was loosing all my power so I mentally quit, I didn't even know it, or want to. Since then I've trained to a 4.6wkg FTP thanks largely to your videos so now I reckon I'd drop him on a Red Bull Rampage bike but that's another story :D
Not true, as you weren't mad nor mentally weak. the shock compression takes place when crank is pushed and the rebound of the shock returns the energy it obsorbed, the rebound happens when you stop putting down power, mostly that's when the crank is pointing down between 5oc to 8oc position, at such crank posittion, the returned energy is not used to turn the crank, instead it's just boucing you up and that's wasted energy. a softer shock wastes more energy because of that. Ofc, morden bike design is so good that the shock barely compresses during the first section of the rear wheel travel, that's can mislead to feel it's not much of a difference, but that's just less wasted, doesn't mean you can avoid it. People really need to start learn physics before doing wrong tests and posting videos about the stuff they don't understand...
Try to get a PR on our local trail for a 1.3 mile climb, I averaged 247w for 6:21 with my suspension fully open for the first lap and then I locked out my suspension for the second lap, felt super fast and easy to pedal with more power, and I averaged 258w for 6:27. 6s slower than open mode even with higher power output, super surprise!
This very issue actually crossed my mind the other day when I was going fast down a trail while fiddling with the suspension lockout knob. It was a pain-in-the-butt distraction, but I wasn't sure if I'd waste power if I didn't fiddle with it. Now I can just leave it and ride in peace.
Wow, this is super interesting. I am curious how cadence affects the results. Maybe higher activation of the suspension leads to less efficient results. Thanks for the information
When I decided to put a rigid fork on my full suspension rockrider, I tried first by just locking it : I gained 1kmh on average (so more once removing the 2kg weight difference). And the front suspension stanchions were actually blocking the travel (I though this will make no difference until big jumps). Explanation IMO : if you have something rigid to put your weight on during force climbing, you use it more. When I replaced the stock spring rear suspension by a lockable one, guess what I was able to put bigger braquets and maintain force climbing longer. Explanation : my body was less pumping up and down to counterbalance the bike movement, so if you have something rigid to put your weight on during force climbing, you use it more, again. Plus the extra bonus on the saddle in flat roads : less pumping means the optimal cadence is higher, you can optimize the effort. Since then, having a road cassette with less gaps became an evidence because you don't have to pay more energy at each gearing changes when accelerating. So yes i loved the feeling of a pumping suspension in terms of torque management, but at some point the maximum reasonable torque you can put is limited, and the same applies to tires (my sweat spot is 2.25 rear and 2.0 front actually).
Great video and nice to see the data to support my feeling half way through this XC season I stopped lock the shock and fork because I wasn't noticing the benefit being locked out.
Measuring at the pedals/crank isn't catching the loss, because the loss happens in your legs, before the power gets to the pedals. If you're pushing against squish, the stroke is different than pushing against a firm resistance to get the same power felt at the pedals.
The power meter is calculating the torque x rpm , but pedal inputs also move the whole system up and down compressing the suspension. The power meter doesn't know that. These are the 'missing' watts that cause the higher HR.
A mind-opener as this is, and consistent with my observations as I think back at my rides and climbs, I think there is one fault in the thinking here. Modern suspension never really locks out - when you "lock it out" you are just telling the damper to consume the suspension energy more effectively, so instead of "losing" energy moving the suspension up and down, you are using it to pump the oil in the damper through smaller orifices and thus keep the frame from bobbing up and down so much. Hence, the only fair comparison is between a proper hardtail bike and a full-sus.
This video can't come at a better time! My friend just asked me to swap my hybrid training bike to his full sus trail bike for a week. Can't wait for that road tire topic video. Question though, as I haven't personally found a credible source for an answer, could I actually train with a mountain bike for road racing? Are there benefits or am I losing gains?
Plenty of pro cyclists race both road and mountain, particularly in the women's peloton (But see MVDP, Pidcock for men's). I'm sure there's slightly different muscle activation from the different geometry, but certainly a lot of positive overlap from a fitness perspective, and the bike handling skills for MTB certainly don't hurt. Dylan himself races both mountain and gravel (which is quite similar to road racing).
@@jamese4729 appreciate the response and insight! Will definitely put this into consideration. I've also noticed myself of a slight improvement. It may just be me getting fitter but seeing that it came from riding my full sus, i think it's definitely part of the equation
Riding an ebike, the only advantage I found to setting the shock to the mid position is that it slightly reduces the chances of pedal strikes, because it helps keep the bike higher in its travel. Depending on the trail, doing climbs at high physical effort and because of the extra speed I find it safer.
Super well done. Thanks for doing this. I ride a ‘20 Spark 900 with TwinLock. I would be interested in seeing Nino’s numbers alongside yours and then maybe an old slow guy like me. My point would be to test if there is much of a difference as you move up the power/watt output capacity. Give Nino a ring and see if he will help. Haha. Thanks again. Good stuff.
Great video and very interesting. Probably explains why I have not noticed a whole lot of difference when locking out on my Supercalibre, particularly when in the saddle. When out of the saddle it feels better because of the firmness, but interesting to know it is probably no faster.
As someone who knows a little bit about physics this makes perfect sense. I always wondered why suspension would be slower. It definitely feels worse tho ;)
I would agree on the data, however I believe "in my experience" when in an all out sprint, locked out is more efficient compared to my suspension left open. At the end of the day, overall most current XC bikes have very efficient peddling performance when suspension is open.
Anecdote coming in hard and fast. I ride a 160/150 trail bike with a suspension setup that favours descending over pedal efficiency. Climbing smooth trails or gravel I just leave my rear shock alone. It’s a fairly modern platform and I never really notice any bob or feeling like I’m losing power. On technical climbs I will sometimes put the “climb switch” in the mid position(not locked, but not full open) on the shock. I feel like the compression makes it so the suspension doesn’t just dive on obstacles and makes for a way more enjoyable ride.
I think the reason why wider tires with lower pressure are more popular these days is because tire manufacturers use much better compound, which has lower rolling resistance. And many people use tubeless, which gives even more advantage. So it is reasonable that 20-30 years ago riders used to pump tires to the max to minimize rolling resistance caused by the rubber and the inner tube.
I'm so confident that my XC bike suspension is so efficient that I plan to race it with the shock up. I bet you that is NOT the case on my 170mm Enduro with cool suspension. I'll test it in the near future. But I always ride it fully open, I never stiffen it up for climbing
I honestly, just cannot believed this based on my experience with *perceived* exertion. Honestly, I can't even pedal my FS bike standing because it bobs so much, I seem to get no-where. The added zippiness when I lock out the real shock on anything but chunky climbs just makes it feel so much faster and efficient. I'm riding a Ibis Ripley AF. I got a HT this year and its just so much faster and more capable (if capability is measured in cleaning technical climbs), it just is. These results are just totally contrary to my experience.
When you have a bike with a suspension meant to go downhill it's immediately evident how much of a difference the lockout makes. Especially with something like strive that further pushes the suspension in besides the lockout. Sprinting it's immediately evident how much more a hardtail accelerates compared to full sus bikes. And the energy does go in to the suspension. Instead of the forward motion it becomes up and down motion through the suspension. So regardless it's obviously beneficial on flat surfaces to make your suspension stiffer. This changes on trail type environments where you are also losing speed by being stiffer.
Very interesting video as always Dylan. Surely the big suspension companies must know all this, is it not in their interests to show the world that suspension does not slow you down?
And frankly most people dont have their suspension set up properly. A proper set up suspension would involved things like reshimming the damper to match rider-bike weight, riding style etc. People barely set air pressure correctly.
I could totally believe a negligible or no difference at the power you tested. Recently I tested maximum sprint power open vs locked out in my tallboy 3 29er and it was less open. That was before I realized my quarq spider was coming undone. I will have to try that again now that everything is fixed. I could see the mechanics of sprinting being different enough create something measurable.
I can’t believe that you omitted comfort being a factor. I am so much faster on my full squish all mountain on climbs and obviously descending despite my hard tail being lighter and some nicer components. I can ride longer at a higher intensity without the jarring. I do however lock out my suspension on longer smooth climbs when looking for a PR.
I ride a Ripmo AF and the only difference I notice when I lock out the suspension is when I forget to unlock it for the descent.
😂
💯 truth!!!
Which can blow up your damping unit if there isnt a blow off like the EXT Storia has.
Truth. I wiped out pretty badly once because of this. Never lock out my sus anymore except if its a 100% tar road ride.
Yup. I'm never locking my suspension for climbs again.
Jesus, who clicked the dislike button!? The man literally summarized studies for you and replicated them on modern racing equipment - what more do you want? Another great video by this legend! And yes, I'm also going to try this on my MTB, alas I don't have a power meter on mine. But I do on the gravel bike, so I'll try it as well and also expecting to be faster on my gravel bike due to just weight: mgh = 1/2 m v^2
0.008666666% of responders
Maybe I’m looking at it wrong, but since you’re measuring power at the crank it’s not a surprise that you had identical times between runs. The efficiency loss shouldn’t be changing between the crank and rear wheel, so maintaining identical pedal power would always result in the same wheel speed on that run, right? If there are efficiency losses, it would be prior to that measurement and you’re not seeing it because you are compensating for it (by trying to maintain exactly 250w).
For example, if having your suspension unlocked actually took, say, 10% more energy, you were automatically outputting 10% more energy in order to get 250w measured at your feet. Overall, you were putting 10% more effort into it, but this isn't captured at the power meter. The extra output is being lost to the inefficiencies. This might explain the higher heart rate?
Maybe, ideally, you would maintain the same aerobic output and then measure the wattage and speed, instead. No idea how you would do that on the trail without a VO2 mask or something…
It’s like the difference between measuring crankshaft hp or wheel horsepower on a car. If you were trying to measure the efficiency changes of a car after making some driveline change, maintaining a fixed output by measuring at the wheel each time would always get you the same speed result, whereas measuring crank hp or even fuel usage is where you would actually see resulting changes.
Or maybe I’m overthinking it…
I like where your head is at. Here’s me doing some overthinking as well (please correct me if I’m wrong here). If the suspension absorbs energy on the downstroke then it will return that energy on the upstroke. Some energy will be lost to friction in the shock but this amount seems to be negligible. GCN talked about something to this effect in their video regarding frame stiffness. That of course doesn’t mean it’s correct.
This is exactly it, measuring power at the pedals doesn't necessarily account for the power being lost in the suspension. There must be energy used to keep the suspension active and bobbing up and down and overcoming friction in the suspension links. This energy doesn't have to be transferred through the pedals, and you can verify this by bouncing up and down on your bike while keeping your pedals motionless, you are compressing your suspension using energy not measured by the power meter. This additional energy may be reflected in the elevated heart rate measurement he took. Its probably relatively small, mostly just to overcome the friction in the links, but if he tested with a larger travel bike with less auti-squat the motion would be more exaggerated and the power required to maintain the pogo stick effect would be higher.
@@DylanJohnsonCycling Oh, I agree, the actual difference might be negligible. Like you and appocketz say, probably the only loss is the internal friction in the spring, fluid flow, and in the suspension bearings (probably turning into heat). And maybe some internal body friction as you bob around a bit more?
I was just curious from a testing methodology.
Now that I think of it, I'd bet most of us here that watch your videos are like minded overthinkers. That's why we love your science based approach!
Well… the energy used to bounce the suspension in the unlocked setup would not be transferred to the pedal stroke when the suspension is locked? 🤔 During a sprint on a road bike, you push & pull hard on your handlebars, to generate more force on your pedals… Don’t you think ?
@@DylanJohnsonCycling
I think you might be able to determine the energy lost into the damper by measuring the temperature rise of the damper (ideally fluid but body temperature could work) locked and unlocked.
That would give you a direct measurement of how much energy is being lost into the damper
Comment from an engineering perspective: suspension systems have basically two components, a spring and a damper. A spring absorbs energy when it compresses, but then returns that energy when it expands again. A perfect spring returns all of the energy that it absorbs and air springs are pretty darn efficient. Dampers are a bit trickier, but they basically resist fast movements, which reduces vibrations (bobbing) and helps protect against bottoming out suspension. Most importantly, dampers don't return energy, but rather dissipate it as heat: this is why suspension gets hot with lots of use, ie at the end of a downhill run. To get significant energy losses through suspension, one would have to pedal in a way that results in relatively large amounts of travel movement at relatively high travel speeds. A steady 250 W up a climb, even standing, likely does not cause this suspension travel, especially with modern bikes designed specifically to mitigate this issue, but maybe an all-out sprint with a very uneven pedal stroke (difficult to reproduce and characterize) could result in noticeable losses.
Yeah thats why Im getting a chuckle about people saying "250! Thats too low!" "Its needs to be 400!"
Frankly loss of power due to loss of traction will be a bigger concern for a larger number of cyclists.
I am not an engineer and just trying to understand. The spring is absorbing energy that you're putting into the bike, but when it expands giving back that energy surely that's then energy that isn't being transferred to the drive train? I get that energy doesn't just disappear, but I don't get how it then goes through the bike to propel you forward. I'm confused but happy to accept the science.
@@ellismccoy the energy ‘returning to the bike’ during pedaling is acting normal to the tire contact patch and that line of action is vertical and not horizontal. This the restoring force does not propel the rider forward. The energy is lost in the form of convective heat transfer from the shock to ambient air.
@@andyjonathan2486 the question was about a spring, not a shock. Also the force vector is not vertical, since a) the contact is slightly but significantly depressed into the ground b) bigger obstacles are approached and dispatched from with a horizontal component.
If you want to understand how the spring suspension without a shock works, imagine riding pumptrack without pedaling
Comment from another engineer- power is being measured at the crank and transferred to the rear wheel via a chain. Neither the front suspension fork nor rear suspension mechanism have any influence on the drive train efficiency so of course Dylan produced the same time up the climb with the same power. The studies which include vo2 measurements are more interesting/ relevant but without reading and analysing i would not like to comment on their findings.
I have done the same test on an SB100. Power within 2W on every lap, and no discernible change in time. This was on an 8min smooth dirt road climb at 305W. I saw 1-2sec difference between runs. I also tested my gravel bike with 40mm slicks, and got 20sec faster… which, doing the math, is exactly what I should expect from the weight alone, so on smooth dirt a 2.4 Aspen at 21psi seems to be just as fast as a 32psi 40mm slick, at least for me.
Id love to see a comparison between say an SB 100 and SB 150. Or something similar.
Obviously a bunch of elements youd need to control for (differing Geo, kinematics, weight etc)
Measuring power put into the drivetrain is not measuring your total power output.
@@brianrhamilton for sure: riding a pump track is a great example. But pedaling up a smooth climb, seated? My muscles aren’t going to move any more or less if the suspension wiggles a little bit. It still feels better to climb locked out, so for long, smooth climbs (like at Shenandoah), I lock it out. But I’m not worried about hitting the lock for a quick climb, since any inefficiency is apparently in the noise.
@@filmaynard It’s not in the noise, it’s just not being measured in these studies because it’s very difficult to do (not because it is small, just difficult).
@@filmaynard yeah Im not understanding Brians comment.
There no were else for power to come from in a significant amount.
Even on a non smooth climb and any where else youd use a lockout any "pumping" would be so minimal as to not call it pumping.
Rockshox Flight Attendant about to have this video blacklisted.
🤣
Haha 😂
Good timing with Rock Shox's latest suspension offering. 🙂
Or Specialized's Brain Technology.
I'd be willing to bet that the seated/standing efficiency loss would be a lot greater on long-travel bikes, which is where Flight Attendant seems to live. I have a 115 mm and a 160 mm travel bike. Both feel nearly identical when seated, but the 115 mm bike is way more efficient when standing. I'd love to have a power meter to test this with, though.
@@TheDavidjakeson same thing I’m about to ask, the Flight attendant, but I think the big difference of Flight attendant is, it has sensor that respond at the speed of 5 nano second(just heard it, don’t quote me), so it’s not completely lockout or open, so it keeps sensing to the type of terrain and respond to the most appropriate suspension setting.
Measuring power at the crank is the reason why the times are all the same for the same power reading. The loss of efficiency occurs before the crank. If you think of the forces acting on the crank, you have the force from leg, and the reactions of the supports. Remove some of that support (ie add suspension with damping instead of a rigid platform) and you need a little extra leg force to get the same crank power. Hence HR is a little higher for the same crank power.
So in your opinion a PowerMeter isn't actually measuring Power (watts)?
@@johnschmitt3083 of course it is measuring watts, at the crank. I'm saying that there is an inefficiency from leg to crank. If you pump your suspension up and down but don't pedal it will read 0 watts. So does that mean the suspension pumping doesn't take any effort or energy?
I love some healthy debate and I’ll admit that I’m not an engineer, my degree and expertise is in exercise science, so I could be completely off base here. Here is me doing some thinking on this but correct me if I’m wrong. If force is lost to the suspension on the down stroke when it’s compressed then the suspension returns it on the upstroke when it extends. GCN did a video addressing this regarding frame stiffness (doesn’t mean they’re right of course). Some energy will be lost to friction in the shock but it seems as though that amount is negligible.
If what you’re saying is true, and I’m not saying here that it isn’t, that would mean that crank based power meters are inaccurate when your suspension is open.
@@DylanJohnsonCycling
No, gas compression cycles are not reversible. Its a basic tenet of thermodynamics. i.e. if you do work (physics 'work') on a gas by compression, you will have losses. This is what other commentator referred to becasue those losses manifest as heat (although these are also friction losses causing the heat). If you want to nerd out you can look up carnot cycle and carnot efficiency.
Now... what those losses are as a percentage of your ftp... is likely marginal. So, for you dylan, your test was too short. In a 4 hr marathon those fractions of % may be 10m, 50m...and for you is that a podium? For me I dont race, so im going to leave the lock off.
That is interesting for sure. I wonder what type of PM would capture that more. Would a pedal based meter be more accurate in that instance? My thinking being that in your pedal stroke, your power would be going to both the crank and the suspension, so would be more representative of the total power your body is producing, vs. what is getting through to the cranks.
The commenters below that stated your power meter measures the power into your chain ring, effectively, and then with a little loss to your chain, cassette and then the wheels got it right. A given power will give you an equivalent speed independent of energy lost in the suspension. Many of us know that energy is power multiplied by time. But energy is also force multiplied by distance - called work in our high school physics class. As the pedals turn, we apply a force at the top of the pedal stroke down the distance to the bottom of the pedal stroke. This becomes the power you see in the power meter. But, with the bike bobbing up and down from an open suspension, your leg has to apply force over the distance of the pedal stroke plus the distance of the suspension bobbing up and down. The power meter only measures the power going into the pedal stroke, not the power pushing the suspension. An obvious illustration of this concept is going down a steep, bumpy decent at high speed without pedaling but standing. You get to the bottom and your heart is racing, yet the power measured on the power meter was zero. That unmeasured power is similar to the power wasted pedaling with the suspension open (standing up) and not being captured in the power meter.
Well put, and as mentioned would also be reflected in an elevated HR vs other efforts.. I think this would be much more evident at efforts greater than 400w that really get the bike bobbing as well.
I couldn't put it in words as you did. Thank you.
I didn't know how to explain that the power meter doesn't include the power responsible for the suspension bob.
I believe the open suspension absorbs pedaling energy meaning that 250W on open will be more exhausting than 250w on closed. This explains the difference in HR.
3 BPM is too marginal to draw that conclusion. A change in breathing, temperature, taking a drink mid-climb or even just before the ride, and most obviously fatigue for sets 2,4,6 over 1,3,5 can all explain a 3 bpm heart rate variability
Well, the studies disagree, since they measured metabolic energy and didn't find a difference there. The 4 bpm difference can easily be explained by him doing the closed runs first, it's well known that heart rate for the same power output can rise over time.
While those 3 BPM are not solid proof. I think we can prove it by logic and math:
Doing the same 250 W and having a bobbing suspension means your body is producing both 250W to spin the cranks AND to move the suspension (which absorbs energy with the dampers generating heat). The power measurement is assuming everything is fixed and all the force is going into turning the crank in circles. However your BB is going up and down and that additional movement accounts for watts being 'lost' and not calculated by the power meter. The PM is thinking you're spinning circles when in reality you're spinning and moving the whole system up and down too, but it doesn't know that.
What I can't believe is how accurately you can hit 250 Watts every run. Great video.
He has a power meter.
In my experience tire choice trumps everything else by a significant margin.
And pressure
By swapping out rear tires I was able to close most of the gap from my xc hard tail race bike to my enduro FS bike. There are literally tens of watts between the fastest and slowest tires by rolling resistance and most of the rolling resistance comes from the rear tire.
@@gte717v which tires would you recommend for a fully suspended cross country bike in 26*2.3 ?
@@squishy_princess Tires are very location and condition-specific, but I'd run a Continental Race King or Trail King for XC use.
Great video, I think it does miss out on one major use of lockout which is that (I think) locked out suspension makes it much easier to sprint, especially from a low starting speed. It might or might not be more efficient, but in shorter XC and short track races, sometimes you need to just get more power out when you get slowed down either out of corner or technical section, I’d argue the benefit to sprinting and the frequency of short little sprints in an XC race is the most important part of having a lockout (course dependent of course). Would be interesting to see sprinting from stopped with lockout and without, and if the lockout allows the rider to accelerate more quickly
When you deadlift sprint a 160mm enduro bike from standstill the suspension compresses a lot so it's pretty obvious how helpful the lockout is.
Looking at your HR when standing, it's clear that standing-open cost more metabolically than standing-lockedout. Even though their 2 avg times were equal, but over the course of a longer effort (multi hours), would they still remain equal? I doubt it. Metabolic cost takes a while to manifest itself, especially toward the end of a long race. It's not all about mechanical efficiency. Both mechanical and metabolic efficiency count. I would say your experiment is interesting for 3-min efforts, but I would not extrapolate it to real world racing just yet, especially if that race is a long one.
Are mechanical and metabolic efficiency not directly proportional to one another? At least if metabolic efficiency changes and all other factors remain the same, mechanical efficiency should drop.
Except that DJ did all the locked out runs first. And so the higher HR on open shock runs could entirely be down to cardiac drift
since making my comment here, I have learned something about (crank based or pedal based) powermeter behavior that makes Dylan's experiment invalid. These powermeters do not take into account the vertical bobbing movement of the bottom bracket when the bike is bobbing up and down. The crank powermeter can only measure power exactly at the crank, but it cannot account for the power required by a bobbing bottom bracket. Crank based powermeters work great for a road bike because the bottom bracket is not bobbing, not so much for full suspension. So, let's say a person puts out 250w on a rigid bike, and that same person puts out 250w on the full suspension bike, well now we know that 250w on the full suspension actually requires more then 250w because the powermeter fails to account for bobbing suspension. This would explain why Dylan's HR is ALWAYS HIGHER in the OPEN/STANDING mode even though he's keeping power output at the "same 250w", but he is actually producing MORE then 250w in the "OPEN" mode, that the crank based powermeter has failed to account for.
The thing to understand here is that suspension act to dissipate energy, and that energy is dissipated in the form of heat. This is why shock fluid heats up when suspension travels. And unless you can account for this loss of energy in your measurement,.. then you're not measuring accurately, and in the case of Dylan's experiment, he is actually under-measuring power when the bike is bobbing in open suspension mode.
@@danielfeary I don't think so, his exercise duration is not long enough to be causing cardiac drift. Anyway, I have posted my follow up comment about crank based powermeter behavior and how his experiment is invalid.
@@jacco2952 Good question. I can't recall, but read somewhere that mechanical and metabolic efficiency are not the same thing. Mechanical efficiency doesn't change much with training, and further more, a pro and an amateur have pretty much the same mechanical efficiency. The reason for this is, I believe, mechnical efficiency depends on the construction of your physical anatomy. For example, blacks have high calf insertion along their leg, and this allow them to run with good mechanics. Asians and whites don't have this high insertion. Now, this doesn't mean a black person will automatically can run faster than a white or Asian, because that white or Asian could train harder and improve their metabolic efficiency (because metabolic efficiency is more trainable than mechanical) and still run faster than the black person. Anyway, since making my orginal comment, I have learned that Dylan's experiment may be invalid after all. See my follow up post above as to why his experiment is invalid.
On my 160mm bike, I notice that climbing smooth trails is just more comfortable with the suspension stiffened up. When I had an XC race bike with 65mm rear travel, I left the shock fully open all the time and it felt great.
There is another reason to reach for that lockout the people often miss: jumps and pump tracks! Having stiff suspension is great for smooth jumps and pump tracks as they allow you to pump transitions way easier.
Dylan, thanks, this was very interesting and helpful. For me the biggest consideration when it comes to the hardtail is not weight but cost. Decent full sus bikes are simply so expensive in comparison. Thanks for your excellent research and informative videos.
really good, light hardtails are, shockingly, ALMOST as expensive.
Excellent video. A couple of things on which I'd like to hear your reaction. 1) Although I can't find the references, I remember some studies suggesting that loss of energy occurs more because of side-to-side compliance than bobbing. Modern rear suspension has gotten very good at reducing side-to-side compliance, but it might be that be that wear in the bearings could give the efficiency advantage to a hardtail for the many riders who aren't going to have the bike's rear suspension rebuilt very often. 2) A long time ago I raced on a bike with a Fox smart fork, and the fork did a good job of responding only to terrain and not to rider inputs. I never really felt that it improved my riding efficiency overall, but I did feel it was a significant aid in maintaining balance when standing up for a sudden surge, like when the trail widens briefly and you need to get around a slower rider really fast. Pretty narrow application, but it did feel like a significant benefit.
I doubt the side to side play from bearings would have a ton of negative impact.
The Nicolai G1 with EXT Storia rear shock uses spherical bearings on the shock mounts to prevent the shock from "stictioning" in turns are the frame etc flex.
I mostly use the lockout out of the saddle. Often after a long grind on the saddle you find a stretch of fine road or less steep gravel and going out of the saddle can be a relief by changing muscle actuation/stress. When out of the saddle the bike definitely bob a lot and does not look to accelerate as well on each pedal stroke. I would be curious of a sprint shoutout.
You just gotta learn how much weight to put on the fork. There is definitely a fine line.
I can have my 100mm wide open and be standing and stroking hard and no bob.
he he...I said stroking hard.
Been riding my FS xc/travel bike on both pavement, XC, and trail terrains fully open for years. I experimented with the complete lockout a few times on the same routes - well, no difference - same effort, same time... So yeah, I don't even bother locking the shock or fork ever! This is a great video/information which confirms what I felt and thought all these years. Thank you for all the testing and data!
This makes a lot of sense, and also shows that new products like Flight Attendant are probably a waste of money. However, one thing not mentioned here is that on bigger bikes in particular, locking out the rear suspension on long steep climbs will keep the rear end of the bike up higher, which makes it feel like you aren't climbing something as steep, keeps the seat angle nice and steep, and helps avoid that slipping off the back of the saddle feeling. That may not be measurably faster, but is more comfortable.
Get yourself a new geo machine! Lol
But in all seriousness suspension plushiness is set by the spring rate and I suspect most people will have a lesser travel bike set up firmer as you need to to have the same sag ratio.
@@tylerbruce5731 always down for a new bike, but I just built a Spire up. So although the right number of bikes is N+1, gotta wait a bit more for another, and aren't many bikes more new school than that. I can definitely feel the geo difference on big climbs with the lockout, although I only use it on paved or fire road sections, unless I forget to unlock it.
@@adanielweaver well the Spire is a new Geo machine. Looks nice, congrats!
I keep thinking I want a Spur but I am really unsure. I like the lightness compared to my Pole and Nicolai but I have a feeling I would quickly regret the lesser travel.
One quick note on doing these kind of tests. If you're comparing 2 (or 4) things, alternate them as you go. If you do 2 runs of X, then 2 runs of Y, then 2 more X, then 2 more Y, you'll (mostly) account for things like HR drift and condition changes.
The thing I get from locking out is the feeling, when I stand with suspensions open I feel it messes up with my posture and movement... Kind of like it makes me lose coordination since the compression and my up and down motion just don't exactly match, if it makes any sense. So when I stand I'd rather lock them except on really steep slopes where I stand really low on the bike and I don't really move up and down that much... But when it is faster and less steep I feel I coordinate better without the pumping motion of suspensions
Really interesting stuff. I have a 40k mostly hard gravel loop with 300M of climbing which I've done multiple times both with and without locked out suspension, and with a great deal of standing. I have to say it feels just as efficient to me, regardless of the settings, which is why I usually leave it in "trail" half way between the two. One thing I'll take away from this is I've noticed my tyre pressure can stand in for suspension, so I'll be using higher pressures, and not locking the suspension on road surfaces from now on. A final note is that I've noticed excessive localised muscle fatigue with fully open suspension, which I believe is due to taxing unusual muscles at the bottom of the 'bounce', this bounce of course depends highly on the rider's weight, and suspension travel, but I believe if done enough, could slow you down.
Thanks Dylan. One of my favourite episodes 👍
As a science and data geek I appreciate your approach and contribution to the conversation. More of this critical analysis and evidence approach is needed in all aspects of our lives. Keep up the great work! Subscribed.
Another great video. Just what I wanted to hear. My hardtail has a non-remote lever and I'm always forgetting to switch the suspension back on. I can now just leave it alone knowing it's not slowing me down on the climbs.
And you can blow your damper if its locked out unless it has a blow off.
So I've now watched several videos repeating similar testing conditions. Primarily using a power meter to match power for every run. Which I believe is ultimately the deciding factor. When riding xc trails or on road the difference between the suspension open or closed is negligible, which if you're an xc racer might be the reason for you to choose no lockout. However from trail riding experience I can say definitively that having my bike locked out has made a huge difference.
On my Scott Genius, going from 150mm of travel to maybe 20mm when locked out there is a significant difference in the amount of effort I have to use when putting the power down coming out of a turn or if I have a fouled climb that I have to peddle out of. The same difference was noticed when I went from being over biked with a Spec Enduro with 170/180mm travel to the Genius with 150/150 or 120/120 in traction, or 20/20 when locked.
Riding with the same groups I was by far the slowest on the Enduro to being one of the faster on the Genius. While the Enduro is a slight bit slacker, the Genius is also in the Enduro class with similar geometry. While I can agree maybe part of this is a mental boost, that mental boost is because it very much feels easier to peddle. Riding the same trails unlocked compared to locked I will put down much more effort with more travel.
The other thing I notice about these test is that to get enough data you have to run a significant amount of runs. Given that you have to do these on the same day to prevent variables such as weather and hydration, somewhat forcing you to do short segments on simpler courses, making the difference in effort harder to measure. Or you have to risk different environmental conditions affecting the results if you were to try to do longer segments on different days.
If lockouts didn't make a difference, they likely wouldn't exist on almost every bike. While remote switches are less common, is there a shock front or rear that doesn't have a switch of some sort?
It could be that the power meter is not capturing your exertion, since the meter is measuring the power through the pedals, not the energy expended bobbing the suspension. Bobbing the suspension comes from the feedback from the ground and other parts of your body, like your arms. If there was a way of capturing the totality of energy expended in your whole body, the answer might be different.
I agree. All this proves is the suspension does not affect the drive train efficiency.
It's mostly the pedalling. The power meter is calculating the force X the RPM , but you're also moving the whole system up and down. So some of the energy is going into moving the system (bb) up and down and the rest into rotating the crank , but the power meter doesn't know that. It assumes you're just spinning circles so same wattage with bobbing suspension is actually more work in reality.
Exactly, pedalling with suspension open you have to add the force needed to compress it to the equation, the damper is working to remove that energy from the system. That force isn't measured by a power meter but you will be working harder to output the same watts.
Timely video since I have been riding a single speed full suspension MTB lately faster than the hardtail I was using previously. The rolling terrain around here make using a lockout a hassle since most climbs are only 30 seconds long.
Wow! I've been one of those constantly locking/unlocking with most climbs/descents. And, I'm definitely guilty of frequently going for the hardtail over the FS XC bike because I think it's going to be more efficient (even though I know I'm sacrificing some on descents). I'm going to minimize all that. BTW, I'm guessing this also translates choosing my slacker 120mm FS bike vs the twitchier 100 mm bike. As always, thanks for the brain food!
Oh, there's an interesting idea here, is there any literature comparing geometry @DylanJohnson? Would be interesting to check how true it is that a steeper seat tube angle improves pedalling efficiency, or that a slacker head tube angle is worse for climbing or tight tracks.
@@AlejandroGarciaIglesias an easy way to do something like this is get a Canyon Strive where you can switch the geo and travel in an instance.
I had one and it taught me a lot about geo and kinematics.
I feel like this is one of the more underrated videos on the channel
Great stuff as always. Not completely parallel, but there’s a reason cars have full suspension and softer pneumatic tires. An additional important point: I would think running open, especially over longer durations and rougher terrain, would substantially reduce muscle fatigue from impacts/vibrations. P.S.
Your research makes me want some suspension on my road and gravel racing bikes for long stages.
Great video Dylan. I have always preferred a lockout and I knew that it probably wasn't much different in efficiency but it does give a psychological advantage when you are standing in sprinting. The main advantage I have found is that I can run my suspension softer but still have a good pedaling platform for smooth terrain. I probably won't worry about the lock out as much anymore. It really makes you think about these new suspension technology like Fox live valve and also the SRAM flight attendant and how they are pretty much a big waste of money.
@@the_fast_life ,🤣🤣🤣 you nailed it on the head.
Rear lockout does help keep the cranks a bit higher thereby helping mitigate pedal strikes and steepening the seat tube angle for a slightly better climbing position.
What about sprint efficiency without and with lockout? Maybe higher power output and different pedaling technique would show better difference and why it might or might not be wise to lock suspension in short uphill or for sprint.
I still think that it has an effect on your body. I don't have scientific research or evidence to back it up, but if you test this up using the same power with the same bike (weight), the difference is gonna be negligible, since power in the simplest form is actually times x how far you move from point A to B. But your hr and rpe will be different. I also think higher power will probably gets you more different outcomes.
@@cesraihandary I think producing 250 watts on the pedals might be easier for the body with locked suspension than with open, so one can't do any meaningful test by keeping power at the pedsl equal. You would need to keep your body effort equal and that is pretty much impossible except in one way: try all out best effort and do this for a while on different days so you are fresh when you do the tests. Then after a while from your best time it should become obvious if 1 option gets you to the top for example 10% faster on average, or if they are always so close that there is no difference.
Funny you posted this video now. I too was fiddling with that this weekend. My fancy bike has been sitting around for awhile. I used it after airing up the fork and tires. I had inadvertently left my shock alone as it felt fine in my neighborhood. I went riding Saturday at my local trails ( flat with roots and quick three pedal accelerations). unlocked fork/ shock as per normal and rode. Rear shock only had 75 psi and was bobbing every pedal stroke so turned on the lockout to stop this. Sunday after airing up the shock to 140 psi, bobbing was less and felt better unlocked. I was a bit faster on the gang ride I was in on Sunday . With the correct pressure, the lockout on my shock is solid (like a hardtail). I had Risse racing revalve it last year to this spec. All I can say is, If the rear isn't spinning under power, and is fully solid when locked, It's a win/ win.
Well done young man. Thank you. I enjoy riding open more but thought locked was faster so spent a good amount of time locked. NO MORE!
I'm shocked! This is definitely top-content!
Nice one mate. Cheers for the reference.
Awesome, thank you! I was thinking of using my full suspension to commute to work beings that I recently got rid of my road bike when I moved to Norway. Wanted to make sure I would be mentally okay with riding my bike to work before getting something more appropriate for commuting.
I have an XC race bike, and I have removed my lockout prior to this.
I just find pedaling with the suspension open, whether it's on trail or on pavement is more comfortable.
The more comfortable I am, and the less my hips bounce around, the more smooth power I can deliver, and I actually "feel" faster and more comfortable pedaling seated w/open suspension than locked.
So glad you did this video, I've been debating for months about whether to put the lockout system back in place on my bike but I didn't want to deal with the extra wires and annoying bob in the locked out position. Since I'm not losing any time anyway that seals the deal, less clutter and things for my brain to think about, just ride.
Awesome video, very interesting
Dude, this was so good. Tho I find it super counter intuitive, bc a) it feels soooo much slower when you're bobbing around, and b) surely there are dampening/suspension losses!!! I'm never bothered with 250 W to lock it out or not... it's more when I'm out of the saddle, doing 400+ W up something steep, or sprinting. You think it's the same story? The bob would be really annoying doing these efforts and I would think def slower (or does just mean I don't pedal smoothly). Still, definitely useful info and I won't sweat it as much going forward - thanks!
This is my thought as well - 250w probably isn't really activating the suspension a ton, I would be interested in seeing a similar test as you mention over 400w, that really gets the bike squishing. I believe it's very possible that there's no meaningful loss or inefficiency, but I think this is more-so where a difference may be if it does exist (vs lower watts).
Great video man. I almost always leave my bike open and I've always thought it worked this way, but you've given me some data now. Thanks. I do like to use a lockout (or firmer mode) in some situations because it feels nicer: some steep climbs let the rear suspension sag more, and it feels like I'm pedaling a go-kart. And when you're going really fast (say start of an XC race) the kinetic energy is so high that the bobbing is more extreme, which constantly changes the geometry of your bike, which is annoying.
Thanks for this vid! Bought a CTY 2.1 as a hybrid bike for mostly trail riding. Upon buying it I found it only has pre-load knobs, and no lockout and was getting a bit of buyer's remorse.
I think I'll still hold onto the bike anyways since I quite enjoy the feel of it and already installed plenty of gear, but I'll also keep my eyes open for any other bikes that catch my fancy.
Theory - on a relatively smooth surface, locking the dampers simply transfers the load stresses fully to the tyres, so the total system suspension and efficiency is unchanged. Instead of ‘vertical’ power being absorbed by oil or air in forks, that same energy is absorbed by rubber and air in tyres. 🤔
But the tire compresses and rebounds sort of uncontrollably and doesn't 'absorb' as much energy as a compression/rebound circuit. There's not (as much) resistance in the 'travel' of the tire , it's more of a basic spring.
I think even with open suspension those watts converted to heat in the damper are pretty negligible unless you're sprinting out of the saddle on a long travel enduro bike for example.
Pinkbike tested this and they found the lockout definitely helps, but it's just a small amount in the best of scenarios.
From personal experience, not long ago I rode with a Fox shock that had its damper blown and found it near to impossible to keep up with the group I usually ride with, sent the shock to service and got the lockout back to a working state, now I can keep up with the usual effort. I don't have power numbers but definitely made a noticeable difference.
Do you have a link to the pink bike test you mentioned? I’d love to see or watch it.
@@cvdavis It doesn't let me post links here, but it's named "Tested: Does a Lockout Actually Make Climbing Faster?"
This video is interesting. I had my lockout lever broken this summer so I was riding around without one for a couple weeks. To my own surprise I had PB times around my local trails. My bike is a Scott Spark RC.
I quite enjoyed this video (and other videos) . Love that you have dipped into mountain bike content!
What matter most when it comes to suspension is kinematics and geometry.
Many people associate longer travel with poorer pedalling performance.
That may largely be due to the fact that historically longer travel bikes (eg Downhill rigs) often have poor pedalling geometry. And may also have poor pedalling kinematics.
My first full suspension mtb was a Canton Strive which allows you to switch the geo and kinematics instantly. It did a lot for my understanding of these.
That allowed me to understand the whole longer slacker concept as well and now I ride a Pole Evolink and a Nicolai G1.
Awesome video I was deciding on hard tail or full sus and I think these days with the newer tech and easy lock out feature I will go for it as a full sus even though it may be a little slower on climbs when going for those few seconds the sheer comfort and efficiency of a full sus makes everything a lot nicer and comfortable and more forgiving.
Great video. I own a Pivot Mach 4 SL... I originally was going to get a lockout installed for the rear, but after riding it through a couple tough training sessions and races I leave it at the mid-setting near 100% of the time. As long as a bike has hyper-efficient suspension kinematics, I won't be thinking about touching the lockout.
Such an interesting video. One thing that you mentioned at the end of the video always occurs to me. Feel. Yes it may not be any faster on paper, but if it feels slower or even uncomfortable, then thats not ideal.
Very interesting! The immediate next question for me that jumps out after learning this, is if there are any disceranable efficiency differences between the "trail mode" and "fully open mode" of most typical 3 position suspension setups !?? Based on the evidence provided here, I would conjecture probably not, and therefore would be more inclined to just always keep it in open mode for the more plush feeling, and have less to think about on the trail. But would love to see this tested the same way as in this video
Another fantastic proper-science driven video (and rather validating as I've not felt full lockouts increased pedaling efficiency).
However, I do find the compression lever, only on the rear, useful to maintain better climbing geometry. Using "trail mode" on most shocks on prolonged steep/technical climbs on my long-travel enduro bike (160mm+) because of their inherently slack (sub-64/65 degrees or so) head angles. As it has quite a lot of sag (and I'm running a coil), I can reap the benefits of a steeper head angle without drawbacks of a loss of traction.
The problem isnt the head angle its the seat angle.
I have a Nicolai G1 which climbs great and its 17+kg with a 62 head angle. But it also has a steep seat angle.
@@tylerbruce5731 Yes, agreed. Should have said both HTA and STA but oversimplified it down to just HA. Should have also add that as I ride a size XL bike with lots of exposed post, the effective STA is even slacker so the compression lever also helps there.
I'd love to see a similar test repeated by somebody who might be a less experienced rider or somebody with a choppier pedal-stroke. I'd imagine you're relatively smooth in terms of power application Dylan.
verry interesting information! Im an XC racer, I rided my HT bike without the lockout knob and cables (weight saving), I needed some adaptation time to all-time open suspension feeling, but very quickly it become natural to ride like that. Now I ride a FS bike, and the most difference I notice is on the longer techy DH sections, where the FS bike let me rest a bit more than a HT bike (hearth rate manage to drop lower due to less body work needed). but I still keep the lockout on the FS :) it come handy on the asphalt sections
Fantastic news! My road/gravel/bikepacking bike is a Specialized Diverge and evidently I needn't worry about any efficiency loss due to the Future Shock,. Meanwhile, my MTB is an old Scott Strike G zero from 2002 which doesn't have any lockout option on either front or rear but I don't have to worry about that either? - Great!
interesting, especially the standing data. was not expecting that standing on a shifting platform would be just as efficient as standing on a stable platform
I think you need to try a new fork with 44mm offset. That has to be the key. In all seriousness regarding inclines, pure system weight (rider and bike) is the biggest factor to consider, additionally, tire rolling resistance (carcass, tread design, compound, pressure and speed of rotation) and of course “aerodynamic drag” on faster moving incline sections. This was an interesting vid that got me thinking about the suspension , we have all been there in the mountains riding up rocky sections on a hardtail vs a decent pedal platform FS, and felt the bike suspension allow the tire to come up and over the obstacle vs a Hardtail that has to push your rider weight(seated) up and over the obstacle- Hardtail - its doing more “work” but typically can be 2-4 lbs lighter bike in the race XC scene. Its very interesting.
Agree, he will be much faster for sure! Every mm counts)))
Oh man, you're doing testing now! Very interesting results. Might I suggest you do another test and expand on a video you made regarding clipless and flat pedals!
Nice! Thank you ….. great vid. Sharing widely!
Need a part 2! This is just mind blowing even as an engineer
very interesting! excellent video as always. When I use the lockout, I often forget to switch it back when I hit the bumpy stuff again. Foregoing the lockout will give me one less thing to think about. I can usually only think about one thing at a time anyway, so this is awesome for me.
Very interesting video. I will try this out on my trail bike as well.
As owner also of a RKT9RDO with the 34-120 fork, I leave the shock and fork in the middle position on paved roads and all the way open on dirt roads and tracks. I think the added comfort makes you quicker at the long run.
But than again, Niner has an excellent pedal platform, could be different for other kinimatics on other bikes.
This is great. I HATED fiddling with my Rockshox remote lockout, which got harder and harder to engage and wouldn’t consistently click back into open.
Same with my Fox step cast forks. When grit gets down in the lockout mechanism it jams up (usually at the worst time). Got tired of F-ing with it so I might as well get rid of the useless lever and cables all together.
@@mmj7700 yep. I ended up just removing the whole lockout system. Allowed me the space to install a better dropper post lever. Good riddance.
As always, awesome content and delivery. Thanks Dylan!
Did a mountain bike race recently on a rooty course on my hardtail. Definitely was significantly slower on downhills. The roots bounce you more and act as a brake every time they send you up instead of down. Very frustrating to watch people disappear away each downhill.
Great timing for the release of RockShox Flight Assistant. 😂
Great video! Measuring power at the pedals eliminates the effect of suspension movement and any losses there. Power expended is all that matters! What’s amazing is how you hit the same power on each run. I would have expected variation there. I think I’ll remove my lockout and save some weight!
Very cool video. Makes me feel better that I'm still riding my Softride road bike.
Cool data, thanks! I did a lot of tests between my XC FS mountain bike and my "gravel bike" and to make the story short, I ended up selling the second. The terrain where I live is extremely steep. I'm gonna do some testing with my bike and see how it goes.
Wow, the psychological effect is huge then (like it is with clipless pedals - see Dylan's earlier video). I came out of winter 19/20 and the first lockdown completely detrained and rode a full sus with a missing lockout lever and got badly dropped by my brother-in-law on every climb. It was my excuse, he was on a hardtail. Next time just a few weeks later I came back with a working lockout and flipped it around, dropping him on every climb. I did no cycling in between (nor running or other material exercise). I do believe your results (given the other papers too) so it must just have been psychological. I believed I was loosing all my power so I mentally quit, I didn't even know it, or want to. Since then I've trained to a 4.6wkg FTP thanks largely to your videos so now I reckon I'd drop him on a Red Bull Rampage bike but that's another story :D
I think this is probably the case of mentally quitting. It feels like your "climbing in mud" so you just quit.
Not true, as you weren't mad nor mentally weak. the shock compression takes place when crank is pushed and the rebound of the shock returns the energy it obsorbed, the rebound happens when you stop putting down power, mostly that's when the crank is pointing down between 5oc to 8oc position, at such crank posittion, the returned energy is not used to turn the crank, instead it's just boucing you up and that's wasted energy. a softer shock wastes more energy because of that. Ofc, morden bike design is so good that the shock barely compresses during the first section of the rear wheel travel, that's can mislead to feel it's not much of a difference, but that's just less wasted, doesn't mean you can avoid it. People really need to start learn physics before doing wrong tests and posting videos about the stuff they don't understand...
Try to get a PR on our local trail for a 1.3 mile climb, I averaged 247w for 6:21 with my suspension fully open for the first lap and then I locked out my suspension for the second lap, felt super fast and easy to pedal with more power, and I averaged 258w for 6:27. 6s slower than open mode even with higher power output, super surprise!
This very issue actually crossed my mind the other day when I was going fast down a trail while fiddling with the suspension lockout knob. It was a pain-in-the-butt distraction, but I wasn't sure if I'd waste power if I didn't fiddle with it. Now I can just leave it and ride in peace.
Wow, this is super interesting. I am curious how cadence affects the results. Maybe higher activation of the suspension leads to less efficient results. Thanks for the information
Good analysis. I'd probably say rolling resistance is the bigger factor. You did touch on it.
When I decided to put a rigid fork on my full suspension rockrider, I tried first by just locking it : I gained 1kmh on average (so more once removing the 2kg weight difference). And the front suspension stanchions were actually blocking the travel (I though this will make no difference until big jumps). Explanation IMO : if you have something rigid to put your weight on during force climbing, you use it more. When I replaced the stock spring rear suspension by a lockable one, guess what I was able to put bigger braquets and maintain force climbing longer. Explanation : my body was less pumping up and down to counterbalance the bike movement, so if you have something rigid to put your weight on during force climbing, you use it more, again. Plus the extra bonus on the saddle in flat roads : less pumping means the optimal cadence is higher, you can optimize the effort. Since then, having a road cassette with less gaps became an evidence because you don't have to pay more energy at each gearing changes when accelerating. So yes i loved the feeling of a pumping suspension in terms of torque management, but at some point the maximum reasonable torque you can put is limited, and the same applies to tires (my sweat spot is 2.25 rear and 2.0 front actually).
Great video and nice to see the data to support my feeling half way through this XC season I stopped lock the shock and fork because I wasn't noticing the benefit being locked out.
Measuring at the pedals/crank isn't catching the loss, because the loss happens in your legs, before the power gets to the pedals. If you're pushing against squish, the stroke is different than pushing against a firm resistance to get the same power felt at the pedals.
The power meter is calculating the torque x rpm , but pedal inputs also move the whole system up and down compressing the suspension. The power meter doesn't know that. These are the 'missing' watts that cause the higher HR.
A mind-opener as this is, and consistent with my observations as I think back at my rides and climbs, I think there is one fault in the thinking here. Modern suspension never really locks out - when you "lock it out" you are just telling the damper to consume the suspension energy more effectively, so instead of "losing" energy moving the suspension up and down, you are using it to pump the oil in the damper through smaller orifices and thus keep the frame from bobbing up and down so much. Hence, the only fair comparison is between a proper hardtail bike and a full-sus.
This video can't come at a better time! My friend just asked me to swap my hybrid training bike to his full sus trail bike for a week. Can't wait for that road tire topic video.
Question though, as I haven't personally found a credible source for an answer, could I actually train with a mountain bike for road racing? Are there benefits or am I losing gains?
Plenty of pro cyclists race both road and mountain, particularly in the women's peloton (But see MVDP, Pidcock for men's). I'm sure there's slightly different muscle activation from the different geometry, but certainly a lot of positive overlap from a fitness perspective, and the bike handling skills for MTB certainly don't hurt.
Dylan himself races both mountain and gravel (which is quite similar to road racing).
@@jamese4729 appreciate the response and insight! Will definitely put this into consideration. I've also noticed myself of a slight improvement. It may just be me getting fitter but seeing that it came from riding my full sus, i think it's definitely part of the equation
@@wintergreene795 great to hear! May the improvements continue!
Riding an ebike, the only advantage I found to setting the shock to the mid position is that it slightly reduces the chances of pedal strikes, because it helps keep the bike higher in its travel. Depending on the trail, doing climbs at high physical effort and because of the extra speed I find it safer.
Super well done. Thanks for doing this. I ride a ‘20 Spark 900 with TwinLock. I would be interested in seeing Nino’s numbers alongside yours and then maybe an old slow guy like me. My point would be to test if there is much of a difference as you move up the power/watt output capacity. Give Nino a ring and see if he will help. Haha. Thanks again. Good stuff.
Great video and very interesting. Probably explains why I have not noticed a whole lot of difference when locking out on my Supercalibre, particularly when in the saddle. When out of the saddle it feels better because of the firmness, but interesting to know it is probably no faster.
As someone who knows a little bit about physics this makes perfect sense. I always wondered why suspension would be slower. It definitely feels worse tho ;)
I would agree on the data, however I believe "in my experience" when in an all out sprint, locked out is more efficient compared to my suspension left open. At the end of the day, overall most current XC bikes have very efficient peddling performance when suspension is open.
Anecdote coming in hard and fast.
I ride a 160/150 trail bike with a suspension setup that favours descending over pedal efficiency.
Climbing smooth trails or gravel I just leave my rear shock alone. It’s a fairly modern platform and I never really notice any bob or feeling like I’m losing power.
On technical climbs I will sometimes put the “climb switch” in the mid position(not locked, but not full open) on the shock. I feel like the compression makes it so the suspension doesn’t just dive on obstacles and makes for a way more enjoyable ride.
I think the reason why wider tires with lower pressure are more popular these days is because tire manufacturers use much better compound, which has lower rolling resistance. And many people use tubeless, which gives even more advantage. So it is reasonable that 20-30 years ago riders used to pump tires to the max to minimize rolling resistance caused by the rubber and the inner tube.
I often also lock out my rear on my XC race bike on the DH because honestly depending the trail I like the feeling a hardtail.
I'm so confident that my XC bike suspension is so efficient that I plan to race it with the shock up.
I bet you that is NOT the case on my 170mm Enduro with cool suspension. I'll test it in the near future. But I always ride it fully open, I never stiffen it up for climbing
I honestly, just cannot believed this based on my experience with *perceived* exertion. Honestly, I can't even pedal my FS bike standing because it bobs so much, I seem to get no-where. The added zippiness when I lock out the real shock on anything but chunky climbs just makes it feel so much faster and efficient. I'm riding a Ibis Ripley AF. I got a HT this year and its just so much faster and more capable (if capability is measured in cleaning technical climbs), it just is. These results are just totally contrary to my experience.
When you have a bike with a suspension meant to go downhill it's immediately evident how much of a difference the lockout makes. Especially with something like strive that further pushes the suspension in besides the lockout. Sprinting it's immediately evident how much more a hardtail accelerates compared to full sus bikes. And the energy does go in to the suspension. Instead of the forward motion it becomes up and down motion through the suspension. So regardless it's obviously beneficial on flat surfaces to make your suspension stiffer. This changes on trail type environments where you are also losing speed by being stiffer.
Very interesting video as always Dylan. Surely the big suspension companies must know all this, is it not in their interests to show the world that suspension does not slow you down?
Scott Genius 150/130/LO I can feel control and faster when suspension matches the trail conditions.
And frankly most people dont have their suspension set up properly. A proper set up suspension would involved things like reshimming the damper to match rider-bike weight, riding style etc.
People barely set air pressure correctly.
I could totally believe a negligible or no difference at the power you tested. Recently I tested maximum sprint power open vs locked out in my tallboy 3 29er and it was less open. That was before I realized my quarq spider was coming undone. I will have to try that again now that everything is fixed. I could see the mechanics of sprinting being different enough create something measurable.
I can’t believe that you omitted comfort being a factor. I am so much faster on my full squish all mountain on climbs and obviously descending despite my hard tail being lighter and some nicer components. I can ride longer at a higher intensity without the jarring. I do however lock out my suspension on longer smooth climbs when looking for a PR.
Especially as you get older. Lol