A transverse bar linking both sides of a suspension system; generally, a torsion bar with rubber bushings mounted on the chassis that allow it to turn freely. The bar's ends are connected to or shaped as lever arms, with attachments to the suspension linkages at each side via ball-joint links, rubber-bushed pivot links, or, on race cars, spherical rod ends called Heim joints. When both wheels take a bump equally, the wheels move the same amount without twisting the anti-roll bar. Individual wheel movement or body roll will force the bar to twist as the lever arms are variously moved, thereby adding the bar's own spring rate to that of the car's springs. Although an anti-roll bar's main function is to reduce body roll in cornering, it also influences overall handling. Installing or enlarging a front anti-roll bar tends to increase understeer; fitting or enlarging a rear bar increases oversteer tendencies. Also called stabilizer bar or, erroneously, sway bar and anti-sway bar.