When we think of the parts that make up a car, often it's the motor, the body and the wheels that we think of first, but between all three there is a system of components that carries out some of the most important tasks in the operation of a car. Your suspension system is primarily responsible for keeping your car controllable and comfortable, without it you would barely be able to drive since even seemingly smooth roads have countless bumps and undulations that would bounce the car around and redirect the steering in unpredictable ways. The most recognisable components are your springs and shock absorbers. Their job is to absorb and dissipate the energy generated by bumps and dips in the road, ensuring that the tyres stay firmly on the road surface, and you don't get shaken and battered around inside the cabin.
The springs support the weight of the car's body and its occupants, and make sure that they aren't bounced around as the shocks do their work. The shocks dampen the sudden movement of the wheels as they move over the surface below. If a wheel hits a sudden ridge (or pothole) in the road, the entire assembly that carries the wheel will move sharply upward (or downward accordingly), and the shocks ensure that this movement isn't transferred to the car and the people inside.
The anti-roll bar or anti-sway bar (often referred to without the anti) is a metal bar that links the left and right sides of your car's suspension. As the name(s) would suggest, Its job is to reduce the rolling effect that's felt during cornering, and stabilize the car when travelling over irregular surfaces.
The rest of the components that make up your suspension will generally vary by the specific suspension style that resides under your car, however linking all of these components, and ensuring that they all operate smoothly, are bushings.
Bushings (or bushes) are essentially cushions made from rubber or similar plastic. They sit between the various parts of the suspension and absorb bumps and shocks, control the range of motion of various parts, and ultimately reduce the noise of the suspension working. They eliminate any metal on metal contact which means that the suspension parts won't wear away at one another over time, and make a terrible creaky racket while they do so. The bushings are the most perishable part of the suspension, and should be replaced as soon as any damage or wear is detected. Luckily, many of them are usually incredibly cheap, and surprisingly easy to replace.
As you might have noticed, all of the aforementioned parts help to absorb the energy from bumps in the road surface. Whilst this ensures your comfort, it is primarily to stop the wheels from bouncing around in an uncontrollable fashion, and to reduce damage to the car as it travels over bumpy surfaces.
Without the various suspension components, your car would shake itself apart due to vibrations and jolts caused by driving over even the smoothest of roads, and you wouldn't be able to steer the wheels, since they'd be thrown all over the place by every little irregularity that they travelled over.
That isn't the only safety concern that your suspension helps with however - since your suspension ensures that your wheels are in the right place at all times, it also helps with braking and cornering.
When you brake, the wheels stop first and the mass of your car wants to keep travelling, hence you will feel the body dip down at the front, before balancing out again - the harder and more suddenly you brake, the more this is felt. It is the job of your suspension to ensure that during this your wheels stay planted on the road and that the energy from the car's body lurching forward is properly absorbed and dissipated.
By the same principle, the suspension also helps with your car's cornering ability. The higher the centre of gravity a vehicle has, and the sharper it is turning, the more the suspension needs to work hard to keep the body from rolling over when the car corners.
I won't bore you with a physics lesson, but the gist of it is that the suspension in your car is primarily concerned with redirecting and absorbing the kinetic energy involved in the operation of your car. Whether that be from the bumps in the road, the changes in your car's direction, or simply stopping and starting - the suspension components are working together to make sure your wheels, your car, and ultimately you stay in the right place on the road.
In short, without its suspension system, your car would be an uncomfortable, unsafe and downright undrivable mess!
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