Anti-Roll Bar
Anti-roll bar, also called a stabilizer or sway bar, is a torsion spring that links the left and right suspension on an axle.
When it generates force
If both wheels move together by the same amount, a conventional bar rotates with little twist. If one side moves relative to the other, the bar twists and adds wheel-rate difference across the axle. It therefore resists body roll and changes lateral load distribution between the front and rear axles.
An anti-roll bar does not prevent load transfer or guarantee more grip. A stiffer bar can reduce body angle but also changes how tire loads are shared, while bushings, link geometry, and motion ratios affect the effective stiffness at the wheels.
For passive suspension geometry and force paths, see Suspension Kinematics and Vehicle Dynamics. Active alternatives are described in Active Suspension.