Well im changing my chain and sprockets. It was sugested I change to a 520. So i picked up a RK gold 520 chain and a rear sprocket thats 520 conversion with 42 teeth. I got a new front sprocket also that is -1. My question is when you convert to 520 I know you need a diffrent rear sprocket then would use for a 525 chain but do you also need a diffrent front sprocket to run the 520 or would the same front sprocket for 525 work for 520?

 

both sprockets need to be 520

 

I agree with walight. The size has to be the same.

edit: otherwise you will damage the brand new sprocket and also the chain. You may even jump the chain and damage the ride let alone you while running that combo.