Please note: this is a USED part

- Highly effective engine to clutch-to-rear wheel power management system decreases unwanted engine braking and rear wheel drag when braking hard for a corner
- Prevents damage to the engine and gearbox by reducing the mechanical stress caused by the back-torque of the engine and avoiding any chance of over-revving
- Provides better clutch feel and smoother action
- Uses original friction plates, drive plates, and basket

How the springs work:
The primary and secondary springs are mounted in such a way as to guarantee a preload which generates an initial resilient spring force.

How the primary spring works:
When the lever is actuated, the preloading position of the primary spring is varied and reduced. The spring returns an elastic force of contrast to the action of the lever.

How the secondary spring works:
The torque generated by the rear wheel tends to raise the drum. The secondary spring is compressed with respect to the initial resting position and generates an elastic contrast force.

All STM clutches and parts are machined and assembled in-house at the STM facility located in Chieri, Italy. Constructed from the highest grade raw materials - CNC machined to the tightest tolerances and hard coated to ensure product longevity.

STM clutches have the ability to be adjusted (tuned) to riders' needs through the use of different weight primary and secondary clutch springs.