The POLINI clutch features a number of options for the set up. Spring preload determines the Rpm at which the clutch engages which allows for optimising acceleration characteristics. By changing the weights on the clutch pads the characteristic of the clutch may be changed from slow dragging to sudden gripping. ATTENTION! Since 98, Minarelli engines (Aprilia, Yamaha) come with new clutches. Please check whether your clutch has two or three shoes. As an alternative, you can measure the inner diameter of the clutch bell, which should be 105mm (2-shoe-clutch) or 107mm (3-shoe-clutch).