I was recently looking to upgrade to a reduction pulley.

Originally, I was looking at the ALTA 15% reduction Pulley. I was told that no belt change would need to be made.
I am now looking at an M7 16% reduction pulley. I was told that with a 17% pulley, a new belt is necessary; with the 16%, is a new belt necessary or are there other modifications to accomodate the 16% pulley?

Thanks a bunch.

 

I used the stock belt with my M7 16% pulley. It is running just fine.