Originally Posted by
patrick112
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?
I'm 5'6" with a 81 cm PBH (different from inseam), which is right near 32 inches. BTW, my trousers are 29" or 30" as the tailor measures them. I usually have a 69 cm saddle height. Except for odd frames, I need a 54 cm c-c, and 52 or 53 can work.
First thing I'd suggest is to double check your PBH measurement. If yours is correct, you have really short legs, and you if you make a change, consider a 52 cm c-c which can accommodate your torso. You might need some help from a good fitter to adapt this thinking to modern frames.
To me the basic numbers are worth double-checking. The correct view of inseam has nothing to do with trousers.