Abstract: Front wheel suspension system for motorcycles comprising relatively spring-mounted elements being associated to the front wheel on the one side and to the ball-head of the motorcycle on the other side. Said spring-mounted elements are constituted on the one side by one single support arm, which arm is connected to the ball-head of the motorcycle and extends along only one side of the front wheel and is provided with guide means, and on the other side by a shift piece, which shift piece is rotatably connected to the shaft of the front wheel and is also provided with guide means, the guide means of said support arm and of said shift piece cooperating with each other. A shock damper means is connected on the one side to the front wheel through the shift piece and on the other side to the support arm.

Abstract: A hydraulic shock damper comprises a hydraulic cylinder and a piston having apertures and dividing the cylinder in upper and lower chambers. Through a flow channel the upper chamber of the cylinder is connected to a dashpot accomodating a partition element. The space being enclosed between the partition element and the closed end of the dashpot is filled with a pressurized fluid. Spaced around the said cylinder a second cylinder is provided, an open connection between the lower chamber of the first mentioned cylinder and the space between both cylinders being provided. Two branch lines are connected to the flow channel and emerge into a single line which in turn emerges into said space. In each branch line an externally controllable closure means and a non-return valve are arranged. Both non-return valves open in opposing fluid flow directions.