The Polini Evolution fan wheel is made for low resistance, but at the same time still ensures good cooling, of the vital parts behind the kickstarter shield. The fan wheel is with plastic ribs, to ensure a low total weight. The lower the weight of the crank, the easier it is to take turns. Remember to be very careful when mounting this fan wheel as it is important the plastic piece is centered. There are also no teeth on the edge of this gear and it is therefore not possible to use the electric starter.