Resently found alot of dirt in the drive belt sliding sheave. Took apart and cleaned up. It now moves freely and bike will pull hills again. But it does not pull as well as it use to. Looking over my service manual I'm thinking that the Primary fix sheave may also need to be pulled apart and cleaned, however as best as I can tell it's not suppose to move in as the sliding sheave does and requires a special tool to reasemble. Does anyone know if in face the primary fix sheave does move in and out and could that be part of the problem since the other one had so much dirty and sand in it?