I wanted to switch my 24" Huffy Good Vibrations from coaster brake to freewheel. Once you're used to a freewheel, with or without derailleur, a coaster can be annoying. Front caliper brake was easy. Rear caliper looked like it would fit so I bought a single speed freewheel and replaced the multi-cog freewheel on a 24" MTB wheel. When I got things together and snugged up, the caliper arms where not long enough. My box of calipers had nothing with a longer reach. I squinted at things for a while, scratched my head, tried to come up with some way to fabricate something to extend the brake, and regretted buying the freewheel. Then inspiration! Because of the angle of this frame relative to the wheel, the calipers would reach farther on the wheel if mounted below the brake bridge (in front of the set stays) instead of the usual location on top. Checked with Sheldon Brown who said this mounting is OK, so here we go. I'll report back after I set up the brake lever and cable and take her for a test ride.