Primary transmission gear up kit Polini 15/49

Polini primary transmission with 15/49 teeth. Inorder to turn performance into top speed, you don`t just need more power - you need longer gearining. Due to manufacturers preferring shorter gearining out of the crate, longer gearing should be fitted in order to prevent over-revving and to tease a few extra mph out of the engine. Simply swap out old for new!