I just spray a whole lot of wd-40 from the can into the back gearset and turn the pedals. I'm sort of new to bikes, and it's not a really good method, didn't know how to do it before, but after this post, I think I'll try other methods. Paint thinner eh? I use about 1/4 of a wd-40 can per clean, and very difficult to keep off the rims.... I don't know where I can get carb cleaner from.