IT wrote:
I am kind of with you. What do we do with this information, if true? He is saying that a flexible bike might flex back at the right time if the the person is in the right gear.
First of all, being in the right gear is key to feel. After that, riders vary so much by size and weight that are we getting into what's a good frame for someone below 150lbs, between 150-175lbs, 175-200lbs and then over 200lbs. Or maybe a better measurement might be watts for a short period of time.
I find it hard to work with the idea that Jan posits.
BQ's test covered a fairly limited scope in many ways, one of which is the
ways in which stiffness was varied across the test bikes. The stiffer bike had a stiffer downtube and top tube than the flexier bikes. I think it would be very interesting to see what would happen if a similar test was conducted that also included bikes that only used the stiffer downtube, or only the stiffer top tube, or other comparable variations. That
the balance of stiffness between different elements could be important is something that's been alluded to quite a bit in BQ, although they haven't explored it rigorously.
In this context, I think this is interesting because Heine himself has favorably reviewed how many modern frames pedal. He's definitely a fan of the 1940s-French-gravel-bike look, but he doesn't seem to think that modern racing bikes generally pedal badly. Are they stiff, and does that disagree with his "planing" narrative? Maybe. I don't know. Maybe it does to some degree, maybe it's complicated. But I think that this discussion often gets damaged by a lot of folks' assumption that Heine thinks that you need a thinwall steel rando bike to have a good-pedaling bike, which isn't really the case.
Eyeballing my Emonda, the ovalized junction between downtube and BB shell will obviously prevent much lateral flex, but it seems like a big more-circular junction would do a much better job of minimizing torsion. Similarly, the narrow seat tube doesn't look like it wants to intervene very aggressively in the matter. If I had a jig that allowed me to measure how different frames flex in different ways and in different areas, I'd love to see how the different pieces of the Emonda interacted with each other, and compare it with my seemingly-not-so-great-pedaling Campeur... or with any of my other bikes that feel different. Alas, I do not.
But, what I suppose I'm trying to get at... and am probably at best vaguely meandering toward... is what I tried to allude to in my first post of the thread. Which is that maybe this isn't so bleak, because even if Heine is mostly right, it might be the case that a lot of frames work for a lot of riders. And that performance-oriented frames are usually going to be at least
pretty good.
I suspect Heine's biggest "planing"/pedaling/whatever beef isn't with racing bikes, but with touring bikes. Perhaps I only suspect that because of the Campeur's seemingly weirdo pedaling. But it does seem to me to be the case. The guy is a big fan of front loading. Partly because the flop effect of front loads can be partially compensated by adjusting steering geometry, whereas rear loads are inevitably tails that wag the dog. But also, perhaps, because a stiffness/flex/whatever profile that's optimal for rear load stability might not be good for pedaling. Maybe. I don't know, but it wouldn't surprise me either.
rruff wrote:
He breathes easier on the *stiff* frame. Obviously, because he is putting out 12% less power! As I mentioned earlier, he is in the wrong gear on the stiffer bike. I don't understand what they were trying to control, but it sounds like some subjective feeling in the legs (with gearing fixed!) rather than a maximum effort.
I checked. The drivetrains of the test bikes were derailleur systems, and it doesn't look like they were holding gearing constant. Interestingly, the article specifically claims easier spinning as a benefit of "planing."