Originally Posted by
Bacciagalupe
As far as I can tell, no such studies exist.
Stiffness does appear to improve control in certain situations, notably on the descents, and probably during sprints. Otherwise, I'm not really aware of any reason why frame stiffness would genuinely improve power transfer.
Imagine my surprise when I saw Cervelo's engineering page stating that stiffness has an actual % gain in power transfer.