Originally Posted by
NotZeroSix
TBH, it depends on the geometry. You just cant rely on the measurement from BB to Seat collar because a 52cm here isnt the same as the 52cm over there. Top Tube length is an important factor as well. Just try out the bikes. Because even within a millimeter of an adjustment can drastically change how the bike feels.
This.
Went from a 54cm Trek 2100 to a 52cm CAAD10.....huge difference. 54cm had me stretch out to the point where I was holding onto the top curve of the bars as opposed to the hoods for 90% of my riding on the Trek. Geometry on the CAAD10 is racy, with a longer top tube than a comparable Trek. 52cm was perfect on the CAAD.