To me, the frame stiffness versus speed debate is almost religion. Some believe it and some don't. I tend to be in the camp that stiffer is faster. Each pedal stroke being an entity comprised of a 'power zone' when the foot has leverage on each side of the crank. When a BB and bike flexes, the circularity of the pedal stroke is lost due to frame deformation. This displacement and eccentricity of the pedal stroke is like going on a wild goose chase. A direct circle is faster with 0 deformation.
Some believe stiffness is all about marketing. I don't but others clearly believe it is all marketing. I sure don't. For example, back in the day of the Vitus, the industry could have concluded that the whippiest frame is the fastest. Why not embrace this paradigm? I mean, why would stiffer be faster if whippy is fastest. And yet, the industry has continually morphed toward stiffer. Decouple lateral stiffness with vertical stiffness to make the bike ridable but make it a vault in torsion.
I would say, most that ride the modern stiffest bikes believe them to be faster. I do. I believe the modern bikes to be the most efficient.
All the top companies...all of them which employ hundreds of engineers and many PhD's...all believe stiffer is faster. They strive toward absolutely the stiffest bike laterally they can create. I don't think this is conjecture, or myth, or marketing, I believe this is what all the top bike makers believe.
The lead designer that created the new Cervelo R3, a bike I just bought...this particular frame and the R5, this bike is purported to be the 'stiffest bike Cervelo has ever produced'. Quite a statement. The lead designer is also a successful bike racer and Cervelo has its founding and history steeped in design and engineering. This bike has log for a downtube and a BB the size of a softball. How long has Cervelo been making race bikes? And what do they believe about stiffness mattering based upon all their testing and bikes that have won races on the world stage? Stiffer is faster.
I believe it as well. I also believe it is a complex analysis and hard to prove but the entire industry believes it.
Last edited by Campag4life; 11-24-18 at 06:07 AM.