I'm 5'10" and I thought a 59cm Bianchi Pista would ruin me, but it actually fits me pretty well. It's because, I think, the stem rises up slightly and my torso is longer than my legs, proportionaly. If you know that you have a long torso and/or long arms, you might get away with a larger size. Make sure it passes the standover test. My bike gets a D.