ER1 Doppler tension spring for 103 SPX with POLINI casing

DOPPLER is one of the few equipment manufacturers to offer this type of product. As in the heyday of moped racing, the central drive spring is an essential option for the variator and the clutch pulley. It allows the variator's progressiveness to be adapted to the engine speed. It allows the spring's stiffness to be adjusted and prevents slipping. The drive spring is mounted on a nylon ball joint.

Please note that on 103 VOGUE S2/S2A/S2Y/VS2/S2Y, the rear mounting needs to be reversed.