Shock absorber with adjustable damping force

The invention relates to a suspension system for a vehicle, in particular for a motorcycle, comprising a shock absorber which provides an adjustable extension damping force, and a damping force controller. The invention aims to provide an improved suspension system that enables the vehicle, in particular the motorcycle, to jump high when needed in a stabilized attitude and run a steep downhill in a stabilized running attitude while restricting the rear wheel from bouncing. Therefore, the invention provides that the damping force controller is configured to determine a downhill running state and/or a jumping start state as a particular running state of the vehicle, and further to automatically regulate the extension damping force according to the determined running state of the vehicle.