Lean steering spatial mechanism for a riding device

A truck for a riding device comprising:

• a closed kinematic chain comprising four rigid bodies and one compliant body, the four rigid bodies comprising a baseplate, an upper pivot arm, a lower pivot arm, and a hanger connected with two laterally spaced wheels;
• a first revolute joint connecting the baseplate with the upper pivot arm;
• a second revolute joint connecting the upper pivot arm with the lower pivot arm;
• a third revolute joint connecting the lower pivot arm with the hanger;
• the compliant body comprising an upper end and a lower end wherein the upper end of the compliant body is connected with the baseplate and the lower end of the compliant body is connected with the hanger, and the compliant body is connected to the four rigid bodies to form the closed kinematic chain, the compliant body transfers torque between the rigid bodies, provides spring force for full load bearing suspension, and provides spring force to return of the kinematic chain to a central, neutral position;
• three degrees of rotational freedom, where a first degree of freedom is rotation about a longitudinal roll axis, a second degree of freedom is rotation about a transverse axis, and a third degree of freedom is rotation about a hanger pivot axis and
• wherein the compliant body couples and constrains the three degrees of freedom of the four rigid bodies.