Originally Posted by RChung (Post 23397802)

Very nice. What were the magnitudes of the effects that were measured?

(I occasionally read Jan's blog posts, but rarely BQ. Are those articles available online?)

Originally Posted by grolby (Post 23397830)

This is all non-responsive. No, Jan hasn’t provided data that supports planing. Yes, he has provided data, but the data doesn’t show what says it shows. Jan’s musings about how a “longer power stroke” allows you to put more power into the bike because you’re not pushing against a brick wall, aren’t a mechanism. He doesn’t explain why this works, and he can’t because the whole idea doesn’t conform to physical laws. Meanwhile, all you’ve got to say in response is that I’m a big dumdum who just doesn’t understand Jan’s brilliant analysis - classic appeal to authority. I’m done with this.

Originally Posted by genejockey (Post 23397851)

Somebody should try stating it as a testable hypothesis and outline methods for testing it. Enough with the handwaving horse poop.

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 Spoonrobot (Post 23397854)

It seems that this has already been done, at least once and did not replicate Jan's finding(s): https://keep.lib.asu.edu/items/134771

I'll see if I can get the full paper.

Originally Posted by grolby (Post 23397830)

This is all non-responsive. No, Jan hasn’t provided data that supports planing. Yes, he has provided data, but the data doesn’t show what says it shows. Jan’s musings about how a “longer power stroke” allows you to put more power into the bike because you’re not pushing against a brick wall, aren’t a mechanism. He doesn’t explain why this works, and he can’t because the whole idea doesn’t conform to physical laws. Meanwhile, all you’ve got to say in response is that I’m a big dumdum who just doesn’t understand Jan’s brilliant analysis - classic appeal to authority. I’m done with this.



Just off-the-charts motte-and-bailey argumentation from Team Planing in this thread. Start with the claim that planing is real and works the way Jan Heine says it does: a kind of flex that allows a rider to produce more power on a bike that has this property than on one that doesn’t, all other factors being equal. When challenged on that idea, retreat to a more defensible but less provocative or even straight up banal argument while pretending that’s what you were arguing all along: “Oh, it’s not 12%.” “It means storing energy in frame flex can be beneficial rather than harmful.” “It means that more comfortable bikes are faster bikes.” I’ve already received a lecture upthread about how French frame builders have been designing frames with flex and souplesse for generations, elsewhere it’s been made clear that Jan Heine is literally selling tube sets intended to “plane” for riders of a particular size and weight, and here you are saying this is a new, relatively unknown phenomenon. In the post quoted below, you suggest that planing is too unpredictable for a big manufacturer to risk incorporating into their designs, yet Jan is willing to take that chance, while elsewhere you have said “consider that major manufacturers don’t know everything about frame design,” (I apologize if that was another poster and I am misattributing, but it’s in this thread somewhere).

This is why the drum I have been beating in this thread isn’t that flexy steel frames are slow, but that “planing” isn’t a well-defined concept, its coiner and most ardent defender can’t explain how it’s supposed to work in a coherent way, and no one can bring themselves to muster a defense for the provocative claim at the heart of the idea - that planing bikes make a rider effectively much stronger than non-planing bikes - without falling back on much more banal and well understood ideas about ride quality, suspension effects and the efficient release of energy stored in frame flex, etc. I love the ride of a high-quality, flexible steel frame and I’m happy to wax philosophical about it for hours, but if that’s what “planing” is, it’s just a rephrasing of all the things people knew and liked about nice bike frames already, not anything new.

Originally Posted by Trakhak (Post 23397856)

That does clarify the claim being made. So the force being returned by the frame represents an additional load that your foot has to push against (torque applied to pull the chain forward + torque applied to oppose the flex returned to the drivetrain). Sounds like more work, not less.

Originally Posted by Kontact (Post 23397862)

You are pretty clearly not reading and just reacting. Look for 12% and try again. You are wasting my time.

Originally Posted by RChung (Post 23397878)

Originally Posted by RChung (Post 23397878)

Originally Posted by Trakhak (Post 23397856)

That does clarify the claim being made. So the force being returned by the frame represents an additional load that your foot has to push against (torque applied to pull the chain forward + torque applied to oppose the flex returned to the drivetrain). Sounds like more work, not less.

Edit: to make my point abundantly clear, "the flex returned to the drivetrain" is weasel wording. The flex, a.k.a. force, that is returned to the drivetrain doesn't magically leap through the bottom bracket and chainring and into the chain.

If what's happening is anything at all like the description says, the returned force is pushing the pedal against the foot, presenting another load that your foot has to work against, in addition to the load represented by pulling of the chain to drive the wheel.

Originally Posted by Trakhak (Post 23397916)

RChung ,

The point I raised above---that the only way driving force can be applied to the drivetrain is through the foot, and that forces being returned as the frame flexes, such as they are, must represent an additional load that the foot must work against--- seems to me to be the core of the problem with claims about planing. If my reasoning seems faulty, please point out my mistake(s).

Originally Posted by Kontact (Post 23397911)

The overall claim was 12% FTP. That is an anecdote about one rider.

Originally Posted by Kontact (Post 23397940)

The chain stay is twisting/compressing, and that relaxes by pushing the bike forward from the rear wheel. It doesn't unwind into the crank but into the other end of the drivetrain.

Originally Posted by grolby (Post 23397830)

TJan’s musings about how a “longer power stroke” allows you to put more power into the bike because you’re not pushing against a brick wall, aren’t a mechanism. He doesn’t explain why this works, and he can’t because the whole idea doesn’t conform to physical laws. .

Originally Posted by Polaris OBark (Post 23398036)

Not so fast ...

About 10 years ago we bought a trampoline for our kids. There were two options, which essentially were "lively" or "safe." We bought the safe one. I tried it a few times, and it always felt kind of dead. The lively ones are designed to be much more elastic. So for the same amount of effort, you can bounce much higher on the lively/elastic trampoline compared to the damped/safe one, which is rather inelastic, and absorbs the energy of the user trying to jump around. It is actually quite exhausting, and in my opinion, ruins the fun. But it does have the merit of reducing collisions and other injuries.

There is nothing remotely unphysical about this kind of explanation. Why would "planing" be any different?

Originally Posted by Kontact (Post 23396668)

.

A Merlin Extralight, that flexes in such a perfectly ergonomic and efficient way it reminds me of when I was a pole vaulter - the bike stores energy and delivers it to the road with perfect efficiency. It smooths the "corners" in my pedaling without losing anything. And it roughs the bumps at the same time.

Originally Posted by Polaris OBark (Post 23397954)

He actually gives two anecdotal examples. One rider shows the 12% difference. The other shows no significant difference. From this, he suggests that not all riders are equally sensitive to planing enhancements.

When I read that (just after I posted this thread), I told my wife it reminded me of audiophool claims about speaker wire. (She just finished with the book.)

Originally Posted by badger1 (Post 23398056)

I dunno; I think all this talk of 'planing' is really kewl; gives new justification for the typical silly bike reviewer talk of 'steeds' that just seem to 'leap forward' once one touches the peddles pedals.

FWIW, given the latest twist on this 'theory' just upthread, I propose a new name for 'planing'; I propose 'inchworming' as a much more accurate simile. Think about it: the frame flexes, and that 'stored energy' is then somehow, by some mysterious process, fed back not to the chainset -- you know, that thing with peddles pedals that actually is turned by the cyclist's legs and drives the bike forward by transmitting that energy to the rear wheel via the chain drive -- but directly to the rear of the frame. Happy to provide a visual demonstration of this process (caveat -- I may, of course, being a non-technical person, have misunderstood this magical mechanism):

https://www.youtube.com/watch?v=H3_H557-vBI

Originally Posted by RChung (Post 23398028)

Do the chain stays relax and push the bike forward after twisting/compressing with the right leg, or the left?