There made for smooth rims really, I tried them on a brand new rim, the were balls. Wacked them on a light grind, WOW they were very good. Still have them in my garage now. Used Plazzies the other week, light grind, they were okay. Dont know what all the fuss was about, so i put them on a new/ fresh grind. they were a tiny bit better, rode down a hill do work. car pulled out. about 4/5 mm on pad ALL over my tyre, have about 1mm pad left.