Originally Posted by
Dunbar
Standover is a silly way to fit bikes to people IMO. As long as you're OK with the longer reach (longer top tube) there is no disadvantage to going with the larger frame. You can put a shorter stem on the larger frame to shorten the reach somewhat. It will have a taller head tube which will result in a more upright position compared to one size down.
sizing a bike by stand-over height worked quite well for average built people when frames were classic triangles with standard angles and level top bars. the length of the top tube was directly proportional to the standover height. minor differences in torso and arm size could be compensated with different goosenecks or stems.
now days, frame geometry is all over the place, especially with hybrids and mountain bikes, so its not even close to a useful measurement.