Abstract: The brakes of a bicycle are actuated in response to rotation of the pedal crank in a reverse direction. The brake actuating mechanism includes an actuating member which is connected to the pedal crank by a freewheel and a slip coupling. The freewheel is disengaged during forward rotation of the pedal crank, and it is engaged during reverse rotation of the pedal crank to move the actuating member and operate the brakes. During heavy braking, the slip coupling reduces the force exerted by the actuating mechanism on the brake operating cables. Movement of the actuating member also unblocks a freewheel which normally blocks reverse rotation of a driven wheel of the bicycle. This unblocking action prevents the pedals from locking after heavy braking.