Minarelli scooter Evo Slider clutch spring d=3.8 Polini

The hardness of the contrast spring plays an important role in transmitting the engine's power to the rear wheel. It exerts counterpressure on the rear pulleys and therefore has a considerable influence on the operation of the variator. The contrast spring is usually harder if the belt tends to slip, if the variator does not operate at the optimal RPM level, or if the engine, despite light weights, continues to run below the optimal RPM. What negatively affects engine performance is a twisted contrast spring. With the Evo-Slider plate, the manufacturer Polini provides a solution to this problem. It is a small plate that is mounted between the contrast spring and the clutch, which reduces torsion to a minimum. In addition, the Polini Evo-Slider absorbs pulley vibrations at high RPM. The result is a smoother engine and better power transmission to the rear wheel. The thicker the diameter, the harder the contrast spring. EVO-Slider Spring (Minarelli) - d.3.9