brakes sticking
 

i know everyone says it's not a great idea to run brakes on nonmachined rims, but i never noticed any saying anything outside of cosmetic/squeaking problems. so, i tried it. but my brakes are sticking very badly. i was riding down a hill and it jammed so bad that i flew off the bike and had to put a good amount of effort into unsticking it. does anyone know if the problem stems from the rims not being machined, my brakes or my brake pads? and how to fix it? i'm running tektro 521AG brakes on velocity chukkers. i've tried cleaning both the rim and the brakes with rubbing alcohol and taking some sandpaper lightly to the rims, though the problem is still there.

So the pad is literally sticking to the rim? It's not an issue with the brakes themselves, or a cable issue?

I'd guess the paint is melting and turning into some sort of glue for your brake pads. What does the rim/pads look like after this sort of thing happens?

I would guess the pad has a lip worn on it and it is sticking toward the spokes. or the pad is riding up the rim (toward the spokes) because the sidewall is not machined. Pics would help. I find it hard to believe the pad itself is sticking to the rim. I would look at something else going on.

Pictures would be very useful here.