Torsion bars use a similar concept to coil springs, but in a different application. One end of the torsion bar is anchored to the frame of your car while the other end is secured to a “wishbone” or control arm. The control arm takes the force of the vertical motion of the wheel when you hit a bump and transfers the force to the torsion bar by acting as a lever. This levering action twists the torsion bar (like a coil) to absorb the energy. Like a coil, the torsion bar has "memory" and wants to return to its original shape - it is this resistance that helps it absorb the energy from the vertical movement of the wheel.