I have steel rims under my cantilever brakes (I'm very sure they're steel...polished and very shiny). Does this combination REALLY take away stopping power, or is this just guessing? Would it help to scrub the rims with a scotch pad (scratching them like crazy) or is that a rumor? This bike is a mid-late 90s Univega Grand Tourismo. Should I change the rims out entirely? I already changed out the pads. Maybe I should get new cantilever brakes entirely (about $20 Nashbar)?