I am buying a Cannondale Supersix Evo Red 22. I am 5'8 and 32'' leg. Not sure whether to get the 54 or 50 frame size. Any suggestions would help.
Go to your LBS and get them to measure you up/fit it. There's far more to it than just leg length, in fact generally speaking body length and reach have more of an impact on fit than leg length (you get a lot of variability in a seat post but not very much in a stem).