Reinforced clutch spring for engines larger than 50cc.
The reinforced clutch spring fits all Vespa clutches with a central spring, such as V50, V50 Special, PV 125, PK, PK S, and PK XL1.
If everything else is in order (such as gearbox oil), a reinforced clutch spring can be used without any issues up to 102cc or more.
The reinforced clutch spring increases the pressure on the friction plates, resulting in significantly improved power transmission and reduces slipping even with much higher engine power.
However, the reinforced clutch spring also increases the force required to disengage the clutch.
Whether the grip feeling is comfortable or too firm depends on individual cases.