Climbing efficiency and why nobody has actually measured it - Tuesday Tune Ep.35
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- čas přidán 14. 03. 2022
- Over the past few years there have been some interesting efforts throughout the bike industry to investigate and understand climbing efficiency. This is understandably important to people, because if you're getting to the top of the hill under your own power, you're going to be spending much more of your time climbing than descending. There's a fair bit to consider, particularly when it comes to measuring efficiency - which turns out to be very difficult to do with bikes.
We dig into some of the attempts to measure climbing efficiency, as well as rolling resistance.
"29ers roll over small children" my main takeaway haha. Cool video good to see you back
You are a breath of fresh air in the cycling industry. Facts and reason instead of "innovation". Thanks for keeping it real!
a good explanation as to why a lot of pinkbike's efficiency tests have had odd results
This was super interesting. I greatly enjoyed this video and hope you make another talking more about how suspension design can influence pedaling efficiency
Great video Steve! I've never seen it put together so well. One small thing I missed in the rolling resistance part is deformation of the ground, aka leaving tire prints. That takes energy too and it is why fat bikes roll better on the beach.
Please continue these "exercises of nerdery"!
thank you very much for sharing your thoughts and knowledge throughout this series!
i am a mechanical engineering student and in every single episode i learned something new! :)
Fantastic explanation Steve. I've thought a lot about the validity of power meter efficiency tests, having done a few myself. I completely agree when it comes to out of the saddle pedalling. Much of the power loss comes from the vertical movement of the BB relative to the rider's torso. This loss is "upstream" of the crank and is obviously not captured by the power meter, which is why efficiency tests with out of the saddle climbing are fairly useless.
However, with smooth seated climbing, the rider's torso doesn't move relative to the BB. The way I see it, with each pedal stroke when the suspension compresses, the mainframe pivots so the rider's COM moves backwards relative to the rear axle. Then as the cranks reach vertical alignment, the suspension rebounds and the COG moves forwards again. This relative movement is of course damped, so power loss occurs, which is *downstream* of the power meter. For a given amount of power at the crank or hub, the bike doesn't go quite as far. It's a bit like pushing a cart uphill by repeatedly prodding it with a damped spring, or riding a hardtail with a large damped mass which is able to move back and forth with each power stroke relative to the frame
When I've done efficiency tests in the past, I measured a small (but bordering on significant) improvement with the lockout on, and Levy was faster when comparing the same bikes with live valve than without. I'm not saying it's a perfect test by any means, but those results suggest there are at least some losses downstream of the power meter.
Agreed gas exchange is the only way to measure overall efficiency. Bikeradar did a video with a sports scientist comparing 26" to 27.5" to 29" for XC, where they used portable gas exchange equipment.
Thanks. I'm not saying there is no such thing as differences in losses downstream of the power meter (including an element of those from suspension), what I am saying however is that what determines how hard a bike is to get to the top of a hill is quite a bit more than that, and that the "power output" measurement (as opposed to a "power input" measurement) unintentionally tends to converge on a given result rather than display the actual differences between bikes - basically, what you're measuring there is how fast a bike gets up a hill with a given amount of power output at the cranks, rather than how hard it is (total calories expended) to for the rider to get the bike to the top of the hill. The two are not the same thing. You can observe this pretty directly - take the chain off your bike, put it on a wind trainer, and sit there and pedal. Your suspension still moves despite there being no drivetrain - this is because your body does in fact move around quite a bit, and the asymmetrically reciprocating mass of your legs alone (ie the further forward leg moving downwards and the other moving upwards) is a big part of the cause. How the bike deals with that obviously varies according to the spring rates, lockout firmness (if there is one), tyre pressures, and biomechanical geometry.
Was just today watching the older videos, great to see a new one.
One thing I've noticed with my power meter is that my perceived effort is very easily fooled by how tired I am and how hot it is. On some days, the rutty 25% grade fire road climb that is part of my regular ride doesn't seem like a big deal. Other days it feel like I'm putting out 100% of my capability just to keep moving. The power meter record shows a lower reading on the "high effort" days than the easy peasy days. This is with the same bike, in the same gear, and sitting with the dropper fully extended in both cases. So even though it feels like I'm working harder on the tough days, I'm actually putting less power into the pedals.
Amd that is maybe more important than your real effort. I always try to make myself the least tired.
Yes, this tracks with my experience. Glycogen, other minor metabolism changes, and all kind of stuff play into it, but yeah... my fast days, I'm fast without even putting out effort. Red zone pinned days, I am just finishing loops 10 minutes later and being outright wasted at the end.
Loved it! Thank you for sharing!
This was very insightful, never thought of rolling resistance the way you explained, thank you!
So nice to hear this. I use a higher rear tyre pressure because a lot of my commute is tarmac. I run 40psi in a Super Trail casing Schwalbe. I also leave my Trek tuned DPS shock in Trail (middle) mode. Lockout on this shock causes too much bounce on the tyre whereas in Trail mode I can feel the tyre and suspension conforming to most bumps.
On really techy climbs (not on commutes so down to 26psi) I actually run my shock in Open on the comp switch and the extra grip is more than worth the higher perceived effort.
nice explanation on rolling resistance
On the rolling resistance, I think the small bumps and nobbly tyres are the same phenomena as your unbalanced tyre patch on the smooth/flat. You forgot to mention the impulse that the bump or tyre nobble gives back when you have passed it (ie on the way down the bump). But the energy you get back is less than the energy that the deformation took from you due to hysteresis.
good to see new video
Here's how you could measure the climbing efficiency: External work done is directly related to VO2. VO2 = (Heart Rate * Stroke Volume) * (arterial oxygen - venous oxygen). Stroke volume is the amount of blood your heart pumps out and is constant. Arterial oxygen is the amount of oxygen that is going to your muscles and is constant. That leaves heart rate and venous oxygen. Heart rate would be easy enough to get with a portable monitor. Venous oxygen you could get with a small prick of blook and a machine like this one: i-STAT 1 | Abbott Point of Care (globalpointofcare.abbott). So you take the heart rate and blood prick and the beginning and end of the climb to get the VO2 at the beginning and end of the ride. The bigger the difference in VO2, the more work was done since VO2 is linearly related to work.
Thanks for the input! Is there any method you know of that would allow that to be monitored in real-time (rather than just start/end)? I suppose on average the start/end system would actually be quite valid though provided you could get the blood sample rapidly enough at each end.
@@VorsprungSuspension Yeah, no problem! Would be a super interesting experiment. I'm not sure of any that you could do real time other than the breathing mask, but like you mention in the video that's more of a lab setting thing. And yeah I don't think you actually need real time info, just start and end. You could definitely get a quick blood sample, all you need is a little prick like they sometimes do at the doctors office. Not a full IV or anything like that. There are definitely other things that affect VO2 that you would likely need to control for like the person riding the bike, temperature outside, when the last workout was, and some other things I'm probably not thinking of, but it could be done!
As for efficiency measurement, I think you could go a long way by loading the rider and frame with a few accelerometers in strategic places. This allow to measure the amount of non-productive kinetic energy produced. Add in shock and fork telemetry for the viscous losses there and you have the major sources covered, no? You'd still miss out on some of the biomechanics aspects and inelastic part of frame deformation but it would be good enough for comparing bike setups I'd argue.
Almost easy answer for this conundrum:
A rear hub with strain gages and an angular speed sensor (ie: a power meter). It will not pick drivetrain losses nor damper and linkage friction losses. You can then substract it from a pedal power meter reading to assess overall efficiency.
Less easy but still interesting: Strain gages and LVDT on rear shock.
That only measures drivetrain losses though, not weight/suspension losses that affect the relationship between the rider's output and the distance covered. Basically, the measure of efficiency should be calories expended by the rider per unit distance/height covered.
@@VorsprungSuspension calories burnt are an empirical measurement, there's no hard way to measure that, so that leaves the shock telemetry as an option, ain't it?
@@puntoycoma47 that's exactly the point - riders are concerned with how hard a bike is to pedal to the top of a hill, and/or how fast they can get it there. Ultimately, "how hard" is the calories required to do it. That's why these alternative forms of measurement using power meters are not valid. Shock data logging won't necessarily give you that data either unfortunately.
Steve is back!!!!
I have started tracking pedaling efficiency in the Hangtime app. The app is already recording accelerometer and gyroscope data for the entire ride to track jumps and turns. Now I have started to analyze the accelerometer data on a climb to track total up/down acceleration. Since the phone is attached to the frame, this approach would account for rolling efficiency change from tier pressure, or suspension setup (although there would be no way to differentiate between the two). Essentially, more total up/down acceleration during the climb is less efficient than than a setup with less up/down acceleration. I don't know how much the variations in the path taken by the rider will affect the results but maybe it will be insignificant compared to differences in suspension setup or tire pressure.
That's a cool approach, I'll have a look into that app. Total absolute vertical displacement of the sprung mass would be a reasonable metric contributing to climbing efficiency for sure.
That was a truly excellent 16 minutes of bike nerdery
Super interesting as usual. Now please develop a Fractive solution for the Charger 2.1
Long time no see！Miss you bro.
thank you for that vid! laught a lot on part with 29ers and children)
Enjoyed this nerd moment, thanks! It doesn't have to come to a conclusion every time as it is more of an exploration. One thing that i have always wondered with respect to contact patch is if the patch's shape changes as pressure is reduced. I suspect that as pressure for a given tire is reduced (and assuming same rider mass pressing down), the shape becomes wider and this can contribute to a slower feel. Kind of like how a fat bike tire's edge knobs can really grab pavement as you turn the bar from side to side. For mtn xc and cross racing, i use this visual to set my pressures and to figure out best pressures for front vs rear. Do you have an opinion on this?
Yeo new upload!
I imagine if you combined a power meter with some telemetry gear could you get a reasonable idea of a bike's "real" efficiency? Basically measuring how much suspension movement there is for a given power output. I suppose you would also need a rider that could supply that power consistently (i.e. pedalling smoothly all the time). There are still a lot of uncontrolled variables but I'm guessing it would show up the difference between e.g. an underpsrung enduro bike and oversprung xc bike pretty clearly.
What we really need are in line chain tension sensors. Like a quick link, but battery powered and bluetooth compatible.
Maybe this is a silly question, but what evidence do we have that pedal-induced suspension movement is always a sign of inefficiency? It seems like a lot of bobbing comes from leg and overall bodyweight oscillation in the vertical plane, no? It's not like that motion would magically be directed through the pedals if the suspension was locked out, right?
@@JakeEpooh that is a good point. The body not a rigid mass, instead is has moving parts and is heavily damped. Huge amounts of energy can be lost in vibrating the body. So if the bike is not moving, is there perhaps more energy loss in the body?
I think that’s why, the best idea still seems like some kind of VO2 measuring.
Thank you for yet another great applied science lecture!
Re 14:20 Does this mean that knobby tires like DHF would roll faster if they're NOT simply inflated to a rock hard high pressure? Maybe just high enough pressure that the knobs on the tire can still be absorbed via deformation under load. I'm going to experiment on a local pump track!
Yes, this is even the case with road bike tyres and the roughness of the road. Rolling resistance reaches a minimum at a specific pressure for any given tyre/rider/road roughness profile; above that and the rolling resistance starts to increase again. www.velonews.com/gear/resistance-futile-tire-pressure-width-affect-rolling-resistance/
This is also the primary reason some tread patterns roll faster/slower than others. Bigger, more spaced out knobs necessarily roll slower than smaller, tighter spaced knobs.
Knobby tires don't have to roll much slower, but the knobs need to be relatively close together, also the stiffness of carcass matters, a thick stiff carcass eats more energy obviously, so do softer, further away knobs, for me the best compromise is a tire with single ply casing and sidewall butyl inserts, light, fast rolling and strong enough, unfortunately only Vittoria makes such a combo atm., everyone else doesn't give buty inserts with single ply casings.
Happy to report back from my local pump track that reducing the pressure on a knobby tire like DHF massively improved rolling efficiency around berms.
There's this double that I've been trying to clear that's right after a berm and I kept thinking more pressure the faster rolling. Nope. Reducing from 40psi to 22psi let me launch out of that berm and oversend the double. It did introduce a noticeable amount of tire deformation when cornering, but I got used to it after a few more runs.
My key take away: 11:28 😀
The bike that you drew looks like a Session.
Hahahaha! YES!!! I love the rolling over small children comment! 😆 I use that analogy all the time!
When will the industry finally release the femoral power meter
Well they only fit UltraBoost femurs, so not until next year...
Until you got a strong pelvis with to right tilt to transmit the force and keep tha bar in your hand.
We'd need some sort of giant hamster wheel no ? A storey high wheel, with rugged surface to emulate trail bumps, and the bike rolling over it (with the front fork stuck in the ground and the weight of a human on the saddle). A motor would run the cranks and you'd measure the rotation of the hamster wheel Vs the energy input.
Or even ditch the hamster wheel, just put the bike on some kind of frame test apparatus with jacks creating different amplitudes of rear wheel travel. You know how much energy you put in the motor and you measure how much you get at the wheel, the difference would be energy loss, no ?
@@guillaumeb6698 by the time you get to rotating the cranks, a significant amount of the losses have already occurred. That's exactly the issue and what makes measurement so incredibly difficult.
@@VorsprungSuspension There may be a subtelty I'm missing but :
If you fix the bike by the frontfork, and put the rear wheel on a treadmill or home trainer rollers, and to emulate rider weight and trail bumps there's a hydraulic jack pushing the bike down at the saddle at different amplitudes and frequency as definded by the test protocol.
Considering you know the motor rpm and power input (these are defined by the tester), if you have another sensor at the rear axle that measures how much the wheel rotates (=how much distance it does) and maybe even how much power is left (as you say that's what a power meter measures at the crank), don't you get the difference ? The loss of efficiency ?
My brain is kind of dumb when there's no visual so I may be missing something :p
could instrumenting the suspension add a little more to the picture? if spring rate, leverage curve and displacement versus time is known you could figure out how much energy is being wasted activating the suspension
If you could separate that data out from the amount of movement that the ground has "rightly" induced while climbing, that could be beneficial, but on its own would not be enough, for the same reason as the tyre pressure considerations - allowing more tyre deflection OR suspension deflection over any given obstacle can reduce the size of the impulse acting to resist the rider's motion, so knowing the suspension motion alone would not really be quite enough.
You should check out the Vo2 master if you want to measure the riders true efficiency!
wait a minute, wait wait, gotta get the popcorn and a beer..... ok, that's better, go ahead.
Over-simplification: when the wheel axle goes up over a bump, it's like a climb in the wheel's perspective. If the tire deforms instead, to the point that the wheel axle's vertical movement is minimal, you basically saved yourself from wasting energy climbing a "micro-hill". All these micro-hills add up. Think of it in terms of plowing through sand: there's a never-ending incline in front of the tire that you are technically trying to climb, set up like a steep treadmill. When the wheel has to lift up a 200 lb gorilla to get up and over a bump, the wasted energy is only that much greater.
Nice video, that was really interesting. Couldn't you simplify the pedaling efficiency thing by ignoring the human component to a degree? Take a few necessary measurements like weight change on the pedals, seat, and bars and then compare that to chain tension, suspension compression and bike acceleration? Obviously it all blows apart as soon as a few bumps come along...
Some how I think I understood this video. Am I right that a power meter can be used to prove if a tyre or tyre pressure is more efficient for a given climb assuming everything else is equal. However as the power meter does not measure forces lost to move the suspension it is not possible to prove if one frame or suspension setup is more efficient that another?
Unfortunately not. Tires are ‘suspension’ just like the fork and shock. The visual concept might be a fatbike and a full suspension bike with roadbike tires. Both will ‘bob’ under pedaling, even without forward movement.
How many attempts did you take to draw that bike so neatly? 😀
One dinner plate and a ruler!
in theory, would a 0 offset fork on a 90* HTA have the best front wheel roll over?
Definitely not, the existing head angle of mountain bikes is actually hugely beneficial for rollover force reduction.
top rate bike nerdery. Love it.
Now I need to buy SRM XPOWER pedals to measure my power in climbing efficiency.
Why not use the full rigid bike power meter result as the standard and then compare to different fs outcomes. Then u can see a % loss?
It wouldn't work. The same problem remains -- the goal is to keep total rider effort equal across runs to test the suspension's effect on speed. So if you're testing a fs bike, you have a problem because you don't know that you have in fact kept the effort equal to the rigid bike (or any other bike), because the fs bike's power meter isn't measuring total rider effort.
Could put the bike on an inclined treadmill since the calorimeter isn't portable.
Wouldn't you just end up with the same problem he described in the video? You're still not measuring the output of the human and comparing against how much work the bike performed.
@@phil_dirt I think he means so that you can use indirect calorimetry to measure the rider's caloric expenditure, which would be measuring the human's output. A treadmill would reasonably simulate a paved road, so you would get some insight there, but whether it's relevant to technical climbing on unpaved surfaces is hard to know. A bumpy treadmill perhaps?
29" climbing up hill with some softballs sized rock sticking out of ground, do i lock rear shock? also what is a good tire pressure, I did not see any psi mentioned. I know everyone is different, but what's the "rule of thumb" if there is one? thanks, good video.
Depends on tire width, rim width, rider weight, tire casing, tube/tubeless setup, terrain, etc. I’m 180lb and ran 25/28psi while tubeless, then 21/23psi tubeless with Rimpact inserts (2.6” wide tires on 35mm rim). Those low pressures are admittedly sucky on jumps, since the tire squirms too much on steep lips, so I’ll run mid/upper 20’s on jumps.
I believe he mentioned pressure in one of his videos, as low as you can go without destroying rims and rolling the tires off the rim.
Ride up one section of it (say 50-100m) twice, once with the lockout on, and once with it off. See which one you felt was easier - that's most likely the most accurate way to work it out.
@Pinkbike maybe rate stuff per your percieved effort and climb after heart rate instead?
Doesn't the diagram you made for the climbing portion with tire pressure apply analogously to descending? I still want to reduce the horizontal force that rocks have on my axles no?
When descending you're likely going faster so the losses from the uneven tyre forces (~ 12 minutes in) balance and then exceed the gains from tyre flex (~8 minutes in) reducing the tangential force component. Probably if you're going fast enough for that to happen you'd want firmer tyres anyway to avoid roll/squirm and burping.
It's still relevant yes. Same applies to the suspension. With descending though, the speeds are obviously a lot higher, so the material damping effects become more significant than they are at low speeds. However yes, optimal rolling speed on rough terrain probably won't occur at super high pressure for the same reason. What @PhillipChenJay said is correct in principle, though there are way too many variables involved for me to tell you precisely where the threshold is that the losses from material damping exceed the losses from reducing the bump force magnitude.
@@VorsprungSuspension That makes sense. Thank you for the info!
epic geekout
@vorsprung suspension please make a smashpot installation video. There's one good one on CZcams but it's German. Please 🙏
Hi, Steve. Can I reprint your videos to Chinese Website ？ For better understanding, I would like to translate your videos and add subtitles. I will not use your videos for commercial purposes, just for better spread the knowledge of mountain bikes suspension. I will indicate the author and your CZcams homepage below the video.
I really like your videos, you put suspension in an easy way to understand how they work and how to better tune it. For many reasons，Chinese people are unable or hard to watch videos on CZcams. I hope I can get your permission.
If the power meter measures power output, couldn't you ride bikes at a constant speed uphill over a set distance and then measure the output on the power meter as a metric of efficiency? With lower watts being more efficient to go the same speed over the same distance?
The problem is that you want to measure power INPUT not power output.
@@VorsprungSuspension Ah I see. Makes sense.
I feel like I'm watching Myth Busters. And PinkBike, your efficiency tests are busted!😆
I’m sorry I’m not an engineer so this thought is probably easily shut down. Would a kinetic energy recovery system like on a Formula One car give an indication of peddling efficiency? I.e. instead of measuring power output measure power collected? I couldn’t tell you where to place the system but in my head it seems like a way to ignore several factors and simplify. And that is the first reason to shoot me down anything that is simplified is probably wrong.
I'm having a difficult time understanding how the suspension is affecting the reading of a crank based power meter? The example of standing and bouncing on the pedals is a red herring. Power is estimated by calculating force and crank rotation. In situations where you are doing stack stands, bouncing in place etc, it's not going to read. That has little to do with actual power measurements on a climb?
There are two ways in which a crank-based power meter will NOT be accurate: pedal velocity is not constant during a single rotation due to the suspension design, or the suspension is actually imparting force into crank. To the first point, if this were actually happening, I'd see way higher cadence deviation looking at per-second data. I don't... To the second point, I have to go with what I "feel", or more precisely what I have never felt: forward propulsion being provided by the suspension.
My opinion: if you really want to measure climbing efficiency, measure power at the pedal, preferably with a pedal like the Favero's which have correction algorithms for variations in pedal velocity, and measure power at the hub with a powertab hub. Compare the delta between the two. It's the same way geeky roadies like me have been measuring drivetrain efficiency on road bikes... Obviously the variable is the rider--but note that you don't necessarily need to ride at a constant power output. The variations in power can be teased out.
The reason is that a certain amount of work done (ie energy expended) by the rider moves the suspension up and down without contributing to moving you forwards - this is "pedal bob" and it's dissipated as heat through the damper and tyres. When you pedal, the sinusoidal power output creates uneven rates of acceleration of the same period as your reciprocating body mass (whole body or just legs). This creates a sinusoidal load pattern through the drivetrain, and at the rear wheel. Furthermore, on technical terrain, you have to deal with the way the bike is able to move up and over obstacles, which necessitates some body mass shifts and suspension movement, all of which expend energy. What you're suggesting does measure drivetrain efficiency, but on a mountain bike that's only a fraction of the overall losses.
@@VorsprungSuspension but how does that affect the power measurement at the crank? Pedal bob is potentially taking away power applied to the wheel, but the measurement at the crank is a direct measurement of power before it's transferred to the chain or to the suspension.
As far as uneven rates of acceleration, while I get this in theory, loads of data with a wired SRM measuring speed at .1kph increments has demonstrated that a sinusoidal power output does not translate into massively uneven acceleration--and for the purposes of measuring efficiency I think the resolution is more than adequate (note, I'd use an actual speed sensor for this sort of testing vs. GPS, which is what most nerdy folks like me do for field testing).
Regarding energy expended overall, taking into account standing/manipulating the bike, we're in agreement there. There's not way currently to measure o2 consumption in the field. I'm imaging a very complex looking single track treadmill right about now... Honestly, the best measure here currently available is simply a known section of trail and a stopwatch... Not perfect, but all that exists... What we DO know is that on a road bike, o2 consumption goes up about 10% on a 4% climb, standing over seated. That's a lot. And it would suggest that if you're able to climb with less full-body effort, that's probably a good thing--and a reason why so many XC racers are now using FS and bigger tires.
@@johno5104 "but how does that affect the power measurement at the crank?" It doesn't, that's exactly the point. Measuring power at the crank measures the OUTPUT power (before drivetrain losses, but after everything else) not the INPUT from the rider. To have any practical meaning, efficiency needs to look at total energy expenditure from the fuel source (in this case, caloric expenditure of the rider) vs how far that gets them. Same reason that the ultimate measurement of automotive efficiency is the figure for MPG or L/100km - you know exactly how much energy the fuel actually contains, and how far that gets you, and it doesn't matter whether the losses are coming from the transmission, the engine, rolling resistance or aerodynamic drag. Same deal for bikes - we can measure drivetrain efficiency, but in isolation it doesn't matter. We can measure pedal bob, but in isolation it doesn't matter. We can measure weight, but in isolation it doesn't matter. If you want to assess efficiency, you have to know energy expended first of all.
Sooo…we all need fat tire bikes 🤙🤙
yay for physics.
You actually gained another follower from pointing out hilariousness of ebike haters "earning their turns" on chairlifts and shuttle trucks.
I would love to run this experiment.
Someone rides the same track a bunch of times. Talking like 100s. A years worth o riding. With a good accurate gps.
Note the variability. Then ride that bike and another bike back to back 100s of times and see if the other bikes data points skew above or below the control bike and if yes, is it within the range of variability. I.e. are all these timed tests just bullsh... I suspect they are.
If you don't like talking about climbing efficiency then how about a video on how to set up DJ bike "suspension" 😜
Do you think there would be a benefit of slightly oval or out of round wheels? Like a oval chainring.
I don't think so - what would they be aiming to synchronise with?
քʀօʍօֆʍ ?
If only you could measure how hard you are working?
Well heart rate does this admirably if you know what you are doing.
It's certainly a step in the right direction, but a lot less precise than indirect calorimetry from what I've been able to find; there are many studies on heart rate monitors for training for example and the error bars on them are pretty huge (I read up on these a couple of years ago when researching HRMs and sports watches). If measured accurately though it might well be consistent enough with any given rider to show the differences, but given that we are usually talking about single-percentage-point changes (often literally 1-2%) in efficiency between bikes I would be surprised if consumer-grade measurements are able to be precise enough. Not saying it's impossible or a bad idea, just that it has some pitfalls too.
Perhaps there’s a way to use heart rate throughout each climb (test) and a measure of blood lactate at the top of each climb (test) - again you would need to know what you are doing like Darryl mentions with heart rate, and need a blood lactate analyser but they’re at least portable and not crazy expensive. Not sure if a continuous glucose monitor could be used as well or as an alternative - less drop in blood sugar = more efficient? I don’t know but someone brighter than me might.
@@timclayton6674 interesting suggestion. Any other sports med specialists who might happen to be reading have any input on that?
@@VorsprungSuspension I think they are doing something similar. performance diagnostics is quite complex and I am not sure if the data you get out of it is of some kind depending on your daily shape which then would be hard to derive to one specific bike.
(Video is in german, but the gear they are using could be interesting)
czcams.com/video/pC1esmXSYCQ/video.html&ab_channel=xc-run.de
Here's the thing, though. How much the suspension is moving up and down has no real bearing on how much energy the rider is expending. For instance, you bounce up and down on your bike, the rear end goes up and down. You then press the lockout. You bounce up and down. You're still expending the same energy (and less peak energy) to bounce your body up and down. You just don't have the suspension also moving. One could argue that the energy captured by the damper and transferred into heat is motion that your body would have had to expend energy to stop.
"Efficient" suspension can somewhat be measured with a power meter, but people are too erratic in their inputs, creating too much noise in the data.
Note: I'm only six minutes into the video so far...
Edit: 11:45 totally agree, lockouts aren't beneficial except MAYBE in out of the saddle sprints and possibly also pavement. My take is that the suspension dictates your rhythm, and in an out of saddle sprint, the rhythm is different than yours and the movement becomes obtrusive
"How much the suspension is moving up and down has no real bearing on how much energy the rider is expending. For instance, you bounce up and down on your bike, the rear end goes up and down. You then press the lockout. You bounce up and down. You're still expending the same energy (and less peak energy) to bounce your body up and down."
The implication that you're making there is physically impossible. If you're causing motion, particularly in a damped system, you are expending energy. Whether you personally consider it significant or not, it requires energy to do. Suspension motion is not the only factor here by any stretch, but it is not up for debate whether or not suspension movement as a direct result of pedaling motion is wasting energy.