Originally Posted by
Fat Boy
We've kinda covered this one. Ultimately, most of us agree on this point. There is the issue of the magnitude of energy involved on the frame side, though. It's tiny and on any frame I've ever heard of or seen, not a legitimate player in terms of wasted energy. It might be a player in bike handling or overall feel, but in terms of getting power from the cranks to the rear wheel, it's essentially nothing.
Yes, this does seem to be a contentious issue for some reason.
The deflection of a very stiff frame achievable by a fit rider is about 1mm to either side, so a full stroke makes it 2mm.
Normal carbon fiber frames deflect 2mm per side, "comfort" frames do about 3mm per side.
So by abusing the pharmaceutical industry "relative benefit" concept that makes them billions, stiff carbon fiber frame is 100% more efficient than a normal carbon fiber frame and 300% more efficient than a budget carbon fiber frame
...in seriousness, I'll try to look for a suitable elastic modulus versus energy formula and get some actual power numbers attached to this.
Cheers,
V.