I have nothing against 650 wheels, I had them on my Trek. But Guru (the company that built my ti bike) didn't seem to think I needed them. The wheels don't look too big for my bike. Only once did I notice toe overlap, when I was making the very sharp turn, uphill into my driveway. It scared me to death, but now I just approach the turn differently. I have 700 wheels on my carbon bike (48 cm unisex frame, with a lot of short reach things on it) and didn't notice any difference when I switched to that bike from my Trek 5200 with the smaller wheels. I do have 25cm tires on the ti bike, which makes it a bit smoother and I could put 28s on there, if I wanted to. The geometry on my ti bike is much more relaxed than the carbon one, so the bike looks bigger, even though the measurements are smaller, if that makes sense. I actually don't like being quite so upright, but I just need to switch the position of the bars a bit.