oh, it's also funny about that guy only wanting carbon for tt.. since in a tt, at a least a typical flat one, weight of any kind is nearly irrelevant after the start, and the rotational vs frame weight even more so. The only thing that matters for TT is aerodynamics. I guess it's easier to form aero shapes out of carbon though? Slightly tangential, but the thread is about evolution and evolution of all these choices is related. It's worth stepping back and seeing if problems are being solved that didn't need to exist.