Abstract: A torsion bar rear suspension has many advantages over standard motorcycle suspensions. They include lowering the center of gravity, lowering total weight, and many others. The torsion bar rear suspension is located underneath the motorcycle's swing arm (9). A linkage system consisting of a linkage strut (8) and torque arm (7) transmits the torque from the swing arm to the torsion spring. The torsion spring is a combination of a torsion bar (5) and a thin walled torsion tube (6). The torsion spring exerts a force depending on the position of the swing arm (9). A damper (12) is mounted on the swing arm (9). The damper is compressed as the swing arm rotates about the swing arm pivot (15). The damper (12) exerts a force according to the speed the damper is compressed.