Abstract: System to control the trim of motorcycles with three or four wheels, the motorcycle having two couples of front and rear wheels, or one front wheel and a couple of rear wheels, or a couple of front wheels and one rear wheel.

Abstract: A four wheeled motorcycle vehicle, comprising: a frame (1), two pairs of two spaced apart swing arms (2FR, 2RR) pivotally mounted thereon at both ends on swing pivot axes (21F, 21R), wherein each swing arm (2FR, 2RR) bears a front (3FR) or rear (3RR) wheel at its other end on a wheel axis (31FR, 31RR); balancer beams (6F, 6R) rotatably mounted on rotation axes (61F) on the frame (1) near their centre, and a pair of at least two linking rods (7FR, 7RR), each linking rod (7FR, 7RR) being pivotally connected to one end of a balancer beam (SF, 6R) at one end and being pivotally connected to one of said swing arms (2FR, 2RR) at its other end. In the upright position of said vehicle one end of each of said linking rods (7FR, 7RR) is positioned below the swing plane extending through both swing pivot axes (21F, 21R) and both wheel axes (31FR, 31RR) of each pair of swing arms (2FR, 2RR), and the other end of each of said linking rods (7FR, 7RR) is positioned above said swing plane.

Abstract: It is described a system to control the trim of motorcycles with three or four wheels, including for each couple of wheels a system of levers (1) linking the hubs of the wheels v(7, 8) belonging to the couple, a shock absorber and one or more dampers (5) directly installed between said wheels v(7,8), or between said system of levers v(1) and a fixed point v(51) on the vehicle frame or chassis.