The invention relates to a trailer (2) for a bicycle (1), having a braking device acting on wheel(s) (4) of the trailer (2); a sensor device (12) which supplies a measured variable, which is a measure of an acceleration force acting on the trailer (2) via a tow bar (5); a controller (18) for controlling the braking device and that is configured to act on the braking device, depending on the measured variable determined by the sensor device (12), such that an inertial force of the trailer (2) generated in the pulling mode or during braking of the bicycle (1) is compensated for or is at least reduced; and a decoupling device (10; 410; 510) which is configured for the partial mechanical decoupling of a movement of the bicycle trailer (2) with respect to the bicycle (1) in the longitudinal direction of the bicycle trailer (L).