Originally Posted by
himespau
can't you just make up that difference with a higher gear (essentially get the same gear inches with a smaller cog in the back assuming you're not already on 52x11?
I could be wrong, but my thought is that 650c vs 700c wheels are going to be very similar in terms of acceleration and aerodynamics. Nfmisso suggested that you should be able to get a bike up to speed more quickly on 650s because you have less weight (at less distance) to spin up, but I think this is offset by having to spin it more quickly. Other people say that smaller wheels are more aero because they have less frontal area, but they have to be pushed harder to cut through the air at their higher rpm rate. My hunch is that both wheel sizes will behave so similarly in these two respects that they aren't good reasons to choose one or the other.
Triathletes flirted with 650c for a while for the aero benefits, but no one showed any real gains, and it fizzled out.