Are you talking about Cannondale's listed size or did you actually measure it using a virtual TT length? My Cannondale CAAD 12 is labeled a 52 but if you measure it the frame size is really a 54. I have a 32.5" inseam and can ride anything from 54-56 frame perfectly. FWIW I spoke to my Cannondale dealer about the sizing and he said smiled and said, "Yeah, it's actually a big 52." I thought that was pretty laughable.