Vehicle suspension movements are transmitted to an anti-roll mechanism which is pivotally mounted on the vehicle for movement about the pitch axis thereof to accommodate normal ride motion of the vehicle in which wheels on opposite sides of the vehicle move equally. Vehicle roll is controlled by an anti-roll mechanism includes a torsion bar which is loaded by the suspension movement. Roll stiffness is controlled by adjusting the lever arm through which suspension movement is transmitted to the torsion bar by a lever arrangement commonly referred to as a Watt's link to assure that the change in the length of the lever arm is directly proportional to the change in the control in the cockpit. Accordingly, linear control is assured, and the torsion bar and lever arms do not appreciable deflect during cornering.