I think many pros are riding a 2cm smaller bike, how do I know? I don't. First, the weight savings. Most bike specs are for their 56cm frames often. If they can ride a 54, why not and it will be lighter by a touch. Second, it gives them the ability to raise the seat way up high, then slam the stem to put them in a more aero/TT position.

This is all theory and BS on my part, but as you noticed, why do their frames look smaller and the seats are high and stems slammed?

All I can say, if the pros seem to be doing it then we must do it too!!

Flame on.