Quality Polini crankshaft scooter with 50cc Piaggio engines. increase the thrust washers and the lubrication hole on the top end bearing longevity / mileage of the shaft. The connecting rod length corresponds to that of the original crankshaft. So is good to use for 50cc / 70cc Sport / Racing Cylinder Polini crankshaft. The delivery includes Polini little end bearing. We recommend to change always the crankshaft bearings when replacing the crankshaft.