Originally Posted by
carpediemracing
WaterRockets have you used your PT to experiment?
I haven't yet. UT_Dude and I are going to use his SRM with my PT on two bikes (my 62cm Ritchey ---
pictured above in Ravenmore's pic, and UT_Dude's 54? 56? Scott). There will be a substantial stiffness difference between the frames, which we'll quantify. If there's a difference in efficiency, then the PT should show a greater difference vs. the SRM on my bike.
My hypothesis remains that we will be unable to measure a difference in efficiency.
Originally Posted by
fuhrermatt
I think the stiffer the frame the better... imagine running in sand... same basic concept.
You should read some more of this thread.
Originally Posted by
schnee
If the energy returned has to be somehow accommodated for by your muscles in any way, that's sunk cost and slows you down by siphoning off energy. If it flexes against your natural motions, that taxes you. If you have to flex your upper body more to keep a noodly bike in line better in a sprint, then that's energy lost. Same way that an overly stiff frame beats you up - your body and muscles deal with all that extra jarring, and that's energy and endurance not spent going forward.
That's one (overly) simple way I can see it being slower.
This is also discredited in this thread.
Originally Posted by
Packeteer
So can anyone who understands this better explain how maybe a bike could be flexy but in an efficient way?
Yeah, make it out of titanium, which is probably the most efficient spring material. Steel is right up there. Carbon fiber is actually a dampener, and will absorb energy through flex. So a CF frame may flex less, but that flex is absorbing some energy, where metal frames return it with great efficiency.
This is also covered in this thread.