An Actuating device for a bicycle is provided. The actuating device may include a static element which is positionally fixed in relation to a bicycle frame, a movable element which is movable in relation to the static element, an electromechanical drive which provides drive force for a movement of the movable element. The electromechanical drive has a motor and a gearing driven by the motor. The gearing may include a first gearing wheel and a second gearing wheel which is in engagement with the first gearing wheel.