To the OP: Are you trying to plant your feet on the ground while on the seat or while standing over the top tube? You should not be able to reach the ground with the former, and it's not even necessary with the latter, but it is nice to be able to. When it comes to traditional frames, my long torso and short legs require a size where I am sitting on the top tube while my feet are flat on the ground. Most importantly, does the bike feel huge while riding it? If so, you might want to try a bike with 650c wheels.
Originally Posted by
stevetone
Probably nothing. However the measurement that was not taken into account is the height of the bottom bracket off the ground. Often with smaller frames the bottom bracket height is raised higher than with larger frames.
That makes no sense to me. The smaller bikes are likely to have shorter cranks, so you should be able to have the bottom bracket lower and still have clearance. Is there a reason they do this that I'm not realizing?