I bought a 2014 Cannondale supersix some years back for a great price. I am 5'8 with a 31 inch inseam, the bike is a 54 cm. 54 cm in other bikes fit me fine, but the Supersix never felt quite right and caused lower back pain. I had a bike fit, and the mechanic put a 60mm stem on there with like a 15% pitch. But the handling has been effected.

So I am going to sell the bike and buy something new. If I go for a supersix 52 cm will I be alright? Or is it likely that the geometry doesn't work for me too?