FWIW the BMC is available in 54 if you are really interested. The guy's/Gals above gave great advice. I know this can be complicated with numbers but one thing to consider. If you go with the 54 and it feels a little cramped you can get a longer stem and open it up. If you go with the 57 and it's way to big, then it's way to big. The good thing is CC has free shipping and lifetime returns.