The diamater of the classic Suntour pulley's are 38-40mm most of there DR's will only take 42mm or smaller. Most modern replacement pulley's run 40-42mm for 10t and 44mm-46 for an 11t sometimes bigger. So when you order you need to make sure that the pulley has a 6mm axel hole and outside diameter of 42 referabley less for it to fit.