A chassis controller controls a shock absorber of a bicycle for spring-assisted damping of a relative movement between a first and a second connecting unit. A damper device and a spring device absorb shocks between the connecting units. A sensor device acquires measurement data relating to a relative movement of the connecting units. A control device controls the shock absorber. The sensor device has a scaling device connected to one of the connecting units and the sensor device extends over a measuring section in a direction of movement of the relative movement. The scaling device has a structure with magnetic properties that repeat periodically over the measuring section. The sensor device has a detector head which interacts with the scaling device, is connected to the other of the connecting units and determines a position of the shock absorber.