How does sway bar work

Or, remove the rear sway bar or replace the existing one with a less stiff thinner bar. And, in that resistance, the bar tries to keep the wheels as level as possible. So, as the vehicle turns a corner and weight moves from one side to the other in the case of a right-hand turn the vehicle rolls over to the right. As the wheel begins to move up towards the body, the sway bar twists which forces the weight to transfer back across to the other side of the vehicle.

The result of this action is that the vehicle begins to level out, thus minimising the roll action when cornering. And this is important to remember because generally car makers are looking for a compromise between comfort and performance. Go too stiff or thick with a sway bar and when one wheel hits a bump the sway bar will try and resist the wheel movement up or down resulting in the vehicle feeling too firm and uncomfortable. And, depending on how the rest of the suspension has been tuned, could even see the vehicle buck off the bump.

Aside from safety, sway bars help prevent lopsided wheel alignment and work to maintain an overall better grip on the road. The easiest way to determine if you need a new sway bar would be by taking your vehicle to a certified mechanic. In the meantime, you should be on the lookout for rattling or clunking noises coming from your suspension especially when going over bumps , poor handling, or a loose steering wheel.

Because of their size, motor coaches can lean quite a bit without a sway bar. A lot of it comes down to personal preference. Share on Facebook. These relatively simple devices, alternatively known as sway bars, stabilizer bars, roll bars or anti-roll bars, bolt to the chassis in a central location across the front and rear axle lines and connect to each side of the front and rear suspension via endlinks.

The way anti-sway bars achieve this function is by twisting, rather than compressing like a coil spring, so its torsional stiffness is what determines its lever force and thus the extent to which it limits body roll. The stiffer the anti-sway bar is, the more the compressing force on the outside of the car is transferred across the chassis, helping keep the inside suspension loaded and increasing its contact patch. This reduces body roll and helps keep some load on the inside tires during cornering, but too stiff a setup can actually reduce the freedom with which each corner of the suspension acts independently, meaning you can start to lift the inside tire in the slower and more severe corners if you run too aggressive a sway bar setup.

WRC driver Chris Atkinson does a great job of explaining this tradeoff in the video below. Diameter is in the denominator, so it gets larger as the amount of twist gets smaller. Further analysis of this formula reveals that torsional rigidity is a function of diameter to the fourth power, which means that even very small increases in anti-sway bar diameter make a large difference in torsional rigidity.