Shock Absorber Type 642 S CompetitionFrom the factory, the Aprilia Tuono 660 Factory is a well made motorcycle, but the stock suspension transmits sharp impacts too directly to the rider. This is partly due to an overdamped rear shock. The Wilbers setup remedies this and optimizes negative spring travel for a more compliant ride. The forks linear 9. 5 N mm springs are too stiff for road use, unnecessarily reducing comfort. For the street we supply progressive fork springs (8. 510 N mm)