Originally Posted by Spoonrobot (Post 23397847)

Do you not understand this image, with the explanation? It's very clear to me, although I'm not an adherent to planing, generally.

https://i.imgur.com/CqzWsLV.png

Originally Posted by grolby (Post 23398887)

“this lengthens your power stroke"

Originally Posted by grolby (Post 23398877)

I didn’t say “FTP.” I said “power,” because that’s what Jan Heine said. I’m quoting Heine directly because I’m trying to take his idea seriously and to respond to the specific parts that I think are wrong. Other people in the thread have said FTP, but I’m not one of them. You’re saying that this claim of a 12% power increase is an anecdote about a single rider, and that’s great! I agree completely! But Jan Heine says that this anecdote proves planing, a phenomenon he defines as allowing riders to produce more power, is real. Meanwhile, another of the interlocutors in this thread has been lambasting me for rejecting this isolated data point. I get that you all aren’t coordinating, but no one here seems to agree on terms or even to be defending Jan’s actual definition of planing, instead selecting a definition that makes sense to the person writing the post. So I’ll lay out the three major categories of planing people seem to be arguing for.

1. Planing is real, strong form. This is Jan Heine’s idea that a bike that planes allows the rider to produce significantly more power, over essentially all durations. This is the idea I think is basically unsupportable given everything we know about physiology and material properties.

2. Planing is real, weak form. This is the idea that frame flex is beneficial and a flexible bike can be faster than a stiffer bike due to factors like a stiff bike causing the tires to skip about. I think this idea is very plausible but the range of circumstances where a bike could have too much drivetrain stiffness is probably pretty narrow. British Cycling has been brought up in this context, and since British Cycling is mostly concerned with track bikes, which have very short chainstays and very skinny tires, that makes sense to me. I don’t really believe that any bikes being used in professional road racing are losing power due to excessive stiffness. With 28 and 30 mm tires now standardized in pro racing, I don’t think a bike in the style of the French constructeurs can plausibly be faster than a carbon fiber superbike on this basis.

3. Not even planing. This is just about the ineffable and romantic qualities of a bike with a really magical ride quality. It’s the feeling of floating over the road while still feeling connected to it, of the mix of comfort and liveliness that the best steel and titanium frames are renowned for. This is definitely a thing and bikes like this feel great irrespective of how fast they are. They’re a joy to ride. It’s just not at all what Jan Heine means by “planing.”

It seems like you’re arguing point number 2, and as I said I don’t really have much of a beef with it. I just a) think the real world circumstances where a bike could be too stiff in the driveline are very rare and b) don’t really think this is the key idea of “planing” as described by Jan Heine.

Originally Posted by Polaris OBark (Post 23398899)

What he writes is "this lengthens the phase of the power stroke", which is subtly different, because he is saying the productive time is increased.

But it does need to be formulated and tested.

Originally Posted by grolby (Post 23398902)

How would the productive time be increased? This is a cyclical motion and the productive time is determined by the rider’s cadence..

Originally Posted by Polaris OBark (Post 23398899)

What he writes is "this lengthens the phase of the power stroke", which is subtly different, because he is saying the productive time is increased.

But it does need to be formulated and tested.

Originally Posted by Kontact (Post 23398901)

I don't think Jan Heine would agree with your summary of number 1, since he actually wrote:


So not that planing allows "riders" to make more power, but that planing - when it exists and "matters", can give that particular kind of rider more power.

What is not being said is that those riders for whom planing 'matters' might be people who have some sort of inability to ride to their potential on regular bikes, and planing bikes merely allow them to ride as strongly as other riders of the same fitness can on any bike.

While everyone gets riled up at Jan's 'extraordinary claims', it seems like people are getting upset about how they are interpreting the claims as a blanket promise of more power if they just dig their steel Miyata out of the garage. Despite the joy so many people take in outrage, this does not actually appear to be the claim.



In 1908 a new type of taste - umami - was discovered. This didn't change cooking overnight, and it took a long time to identify the taste receptors and everything else, so the concept wasn't scientifically recognized until 1985. Everyone seems pissed that Heine isn't just trying to identify planing, but also serve as a single source science powerhouse to conclusively prove its existence

Get over yourself, cyclists. If you feel this concept is so interesting/problematic/important, do the study yourself. Crowdfund the cost of testing, contact universities that already do bicycle studies (UW Madison has one). Heine does not have an obligation to prove anything to you.

Originally Posted by Polaris OBark (Post 23398903)

Instead of x degrees being productive, if 2x degrees of the cyclical motion are productive, the productive time is doubled (I am using an arbitrary multiplier here, not suggesting the effect is really that pronounced).

Originally Posted by grolby (Post 23398908)

This is a bit silly. You’re participating in this discussion with as much vociferousness as anyone else. It’s true that Heine isn’t obligated to prove anything, but he’s not here and we aren’t obligated to believe him, either. Jan Heine put an idea out into the world, and it’s an interesting and provocative enough idea that it inspired our OP to ask if others thought it was real. Well, those of us who don’t think it’s real said so. No one forced you to come in and argue back. But people like talking about things and if everyone just agreed that Jan was correct, there wouldn’t be much of a thread here, would there?

Originally Posted by grolby (Post 23398887)

I quoted this passage earlier. I understand it, in the sense that it consists of grammatically-correct English phrases. The problem is that “this lengthens your power stroke, allowing you to put more power into the bike,” doesn’t make sense. It isn’t an explanation of anything and neither “accepts extra power,” nor “longer power stroke” follow logically from a lack of hysteresis in a flexing bike frame. There’s no particular reason to believe that pedaling a stiff bike is like pushing against a brick wall - after all a crankset moves under power and a brick wall does not. It’s been pointed out already that it should be pretty easy to demonstrate power losses caused by excessive drivetrain stiffness. Where’s the data?

Originally Posted by john m flores (Post 23398941)

Yup. This idea that a rider with, say, 300 watts of power should not send all 300 watts into the drivetrain, but instead should send 200 watts to the drivetrain and the remaining 100 watts into bending the frame because the unbending of the frame that happens moments later is going to somehow propel the bike forward with up to 12% more power. Huh?

If planing is so efficient, why do we even have drivetrains - let's just bend and unbend frames!

​​​​​​The only way this remotely makes any sense is if there's a 12% loss while on the pedal's downstroke that is not lost during the unbending. And as you said, that drivetrain loss should be measurable

What hasn't been explained is how the power from the unbending frame results in forward motion. No, the stick and prosthetic examples don't count; they are simple, 2-dimensional models where the bending and unbending lie within the same plane. The bending of a bicycle fame is a very different animal..

And btw, I don't think those aren't finite element analysis models, they are simple force diagrams.

Ultimately, the burden of proof of planing lies with those supporting the theory, not those skeptical of it. The traditional method of presenting that proof is having others repeat the experiment and results. That burden has not been met. It's been six years.

Originally Posted by Trakhak (Post 23398994)

Is there any reason the planing hypothesis couldn't be tested by any of us with a wheel-off smart trainer?

Mount a succession of your bikes on the trainer, ride at a particular power level(s) at several cadence levels, and record the speed changes.

Since there's no rear wheel, tire hysteresis is eliminated as a factor. The rear of the frame is held in place as firmly as if by a wheel.

Also, if one argument is that, in effect, frame flex first shortens and then lengthens the chain stays, driving the bike forward (I admit that I don't understand that claim fully), you could even paint the front tire where it contacts the floor or whatever, so that paint marks on a sheet of paper on the floor show that the tire moves forward as the chain stays return to the resting position (and, of course, that the tire then moves back: the flex giveth, and the flex taketh away?).

Testing planing frames should unambiguously result in higher speeds for a given power level and cadence. Unless I'm missing something.

Edit: it would probably be best to use the same gear combination on all the bikes.

Originally Posted by Kontact (Post 23399016)

Why would a device that traps the rear triangle into one plane simulate the dynamics of a wheel on the road that is free to twist?

Originally Posted by Trakhak (Post 23399029)

The frame is no less free to twist secured in a trainer than otherwise, unless you're suggesting that tire hysteresis and spoke flexing or whatever are crucial to the effect.

Anyway, I'm hoping for a response from someone who has the academic background to evaluate the validity, or lack thereof, of such a test.

Originally Posted by Carbonfiberboy (Post 23398895)

We also know that fast riders use a pedal stroke with a definite force peak somewhere near the middle of the downstroke. So that's a pressure peak on the pedal, much like when the runners foot or substitute therefor has it's maximum downforce against the running surface. So it's not unbelievable that extending the pedal downforce a little might be a positive thing, force * duration. Whether that happens or not we can regard as an open question until someone uses a set of power pedals to confirm that happens. Should show in the graph of tangential force. [...]
Edit: about the mention of power pedals above. Of course if the bike is faster, that means that more power was applied - TANSTAFL. The theory would be that a similar force was applied to the pedal but over a longer duration, which of course also means that the rider's leg applied the force over a longer duration, so just maybe the whole thing really is BS. Well, except that the force magnitude was not increased, just its duration, which should be less tiring.

Originally Posted by Trakhak (Post 23399029)

The frame is no less free to twist secured in a trainer than otherwise, unless you're suggesting that tire hysteresis and spoke flexing or whatever are crucial to the effect.

Anyway, I'm hoping for a response from someone who has the academic background to evaluate the validity, or lack thereof, of such a test.

Originally Posted by Eric F (Post 23398590)

A tennis racquet benefits from the stiff frame supporting the trampoline effect of the strings. String tension is adjustable

Originally Posted by RChung (Post 23399041)

The Kautz data from instrumented pedals are here. A publication based on those data is here.

In summary, they looked at "elite national" level riders and "very good state or regional" level riders and studied their pedal stroke with an instrumented pedal. The elites produced more power, sure, but both groups had "similar" shapes in the sense that the peak torque phase was in about the same place and the duration was about the same. However, the elite group's strokes were *less* round than the very good group. That is, the main difference is that the elite group stomped down harder and didn't lift up their foot during recovery phase. But you can examine the data yourself if you wish. (This is an early example of publishing the data so that you can do verification or replication yourselves). An interesting wrinkle is that the study included some data when "stompers" were asked to lift their foot on the back half of the pedal stroke to make it "rounder." There is some contribution then, but it was almost exactly matched by a reduction in peak torque on the front half, and HR increased. So this suggests that trying to make the pedal stroke rounder didn't really change power production but it raised HR.

Originally Posted by john m flores (Post 23398941)

Yup. This idea that a rider with, say, 300 watts of power should not send all 300 watts into the drivetrain, but instead should send 200 watts to the drivetrain and the remaining 100 watts into bending the frame because the unbending of the frame that happens moments later is going to somehow propel the bike forward with up to 12% more power. Huh?

If planing is so efficient, why do we even have drivetrains - let's just bend and unbend frames!

​​​​​​The only way this remotely makes any sense is if there's a 12% loss while on the pedal's downstroke that is not lost during the unbending. And as you said, that drivetrain loss should be measurable

What hasn't been explained is how the power from the unbending frame results in forward motion. No, the stick and prosthetic examples don't count; they are simple, 2-dimensional models where the bending and unbending lie within the same plane. The bending of a bicycle fame is a very different animal..

And btw, I don't think those aren't finite element analysis models, they are simple force diagrams.

Ultimately, the burden of proof of planing lies with those supporting the theory, not those skeptical of it. The traditional method of presenting that proof is having others repeat the experiment and results. That burden has not been met. It's been six years.

Originally Posted by Koyote (Post 23399033)

I've only skimmed this...But it seems like there's an argument over whether a bike frame, by flexing and unflexing in the stays while pedaling, is capable of storing and releasing energy -- in a degree which is perceivable to the rider.

If I've got this correct, it's absolutely nuts. As in, not even worthy of consideration.