On the BOSS system, the movable sheave (the sheave that moves to allow the belt to move lower into the clutch) slides on the driven shaft, rather than on a separate steel post that’s built into traditional driven clutches. The result: a 0.25-lb. weight reduction and quicker acceleration.

The area of the driven shaft on which the clutch slides/moves is polished for improved performance and increased bearing life. The shaft itself is larger diameter than traditional shafts.