Why use sway bars, stabilizer bars or anti-roll bars?

There are many reasons, however the prime reason a bar is fitted is to maintain maximum tyre contact with the road. Suspension systems are designed to vary the angle of the wheel and contact patch as a vehicle travels along the road. The optimum contact patch is achieved with the wheel in the vertical position. Braking, body roll, body yaw, squat and dive all cause the shift in contact patch.