>>20069265'7" is a cursed, in-between size. King of the manlets but midget of the kings. I'm about the same size with the curse of having long arms/legs with a short torso. You have to approach every bike individually because some smalls are too small, some mediums are too large, in every case, you'll need to adjust the stem lengths. It sucks being on the extreme ends of a size. Now for your 20.5in bike, it depends if it's a MTB or road bike whether it's oversized for you or not. If it's road bike geometry, then 20.5in downtube is close to optimal but if it's MTB geometry, then it's way oversized.
