You have me wondering. I am in the market for a CAAD10 by the year end. My LBS doesn't have women's versions. So I am going to try a men's. I am riding a 51 Synapse now and have shortened the stem and got a different seatpost allowing me to get closer. Maybe I need a 48? I am 5'4 1/2" and short inseam probably near a 29. Well, Ia m going to test ride hopefully on Thursday so I guess I'll know more then.