How car suspensions work

At first glance, it seems that the car suspension works quite simply. If the bumps end up being less bumpy, then all is well, right? In fact, the suspension system requires a lot of work, and the components…

At first glance, it seems that the car suspension works quite simply. If the bumps end up being less bumpy, then all is well, right?

In fact, the suspension system has a huge number of functions, and its components must withstand enormous loads compared to other major vehicle systems. The suspension system is located between the frame and the wheels and serves several important purposes. Ideally, a well-tuned suspension will absorb bumps and other bumps in the road so that people in the car can travel in comfort. While this is very important from the passenger's point of view, the driver will notice some other features of the suspension system. This system is also responsible for keeping the wheels on the ground as much as possible.

Wheels are extremely important to the performance and safety of a car. The wheels are the only part of the car that touches the road. This means that they have to transmit power to the ground and drive the car at the same time, as well as be responsible for stopping the vehicle. Without a system to absorb bumps and potholes in the roads, the car will shake and wobble on uneven ground, making it nearly unusable due to lack of traction. While the suspension system is a great solution for bumpy roads, it makes the job much more difficult when you consider that the wheels are now responsible for all their standard duties and now have to move up and down to absorb bumps from bumps. the handle of the car does not seem to be on springs and it is thrown at every turn.

That is why the suspension system is very complex. There are many parts involved here, and one broken or bent part can ruin an entire setup.

How does the suspension system work?

For the most part, modern cars have independent front and rear suspension, allowing each wheel to move independently of the others. However, some vehicles use a simpler solid axle due to the lower cost and simpler design. The only solid axles still used in new vehicles are drive axles. The drive axles have drive wheels at each end, while the dead axles have free spinning tires at each end. The problem with rear tires that don't move independently of each other is that they always maintain the same angle relative to each other, not relative to the road surface. This means less grip and less predictable handling. Up until the latest iteration, the Ford Mustang used a live axle and was heavily criticized for sacrificing performance for nostalgic handling.

Beam axles also contribute unnecessary unsprung weight. Unsprung weight is the weight that is not supported by the suspension. The mass supported by the suspension is called the sprung mass. The low unsprung weight compared to the sprung weight makes the vehicle lighter and more dynamic. The opposite provides a harsh ride and a feeling of less control over the car. If the differential that sends power to the wheels through the axles is attached to the vehicle's frame or body rather than the axle itself, then the unsprung mass is significantly less. This is one important reason, among the many other benefits of being able to drive one wheel without significantly affecting the other wheels, why independent suspension is almost universally used by automakers for the front and rear wheels of their vehicles.

Independent front suspension allows each front wheel to move up and down with a spring and damper bolted to the frame at one end and a linkage or wishbone at the other end. The control lever is attached to the front of the car closer to the center at one end of the lever, and the steering knuckle is attached to the other. The wishbone does the same, except it attaches to the frame at two points, resulting in a part that resembles a wishbone. The location of each component in an independent front suspension system is very important, as the front wheels must turn and maintain constant alignment in order for the vehicle to operate safely.

The independent rear suspension uses the same technology as the front without considering steering dynamics, as the rear wheels are not normally steered. RWD and XNUMXWD vehicles have a differential mounted on the frame in the middle of the control arms or wishbones, while front wheel drive vehicles have a very simple rear suspension requiring only springs and dampers.

The dampers and springs provide all the damping and compression as the suspension moves. The springs provide the force that keeps the sprung weight away from the wheels and resists compression. Shock absorbers are oil-filled cylinders that cause the suspension to compress and decompress at a constant rate to prevent the springs from bouncing up and down. Modern shock absorbers (or dampers) are speed sensitive, meaning they handle lighter hits more smoothly and offer more resistance to larger hits. Think of springs as guard dogs, ready to furiously protect your car from bumps. The shock absorbers will be the ones holding the guard dogs' leashes, making sure they don't go too far and do more harm than good.

Many cars, especially smaller ones, use MacPherson struts located in the center of the coil spring and acting as shock absorbers. It saves space and is lighter.

How does the suspension system improve passenger comfort?

When the ride or comfort of the car is good, it means that the suspension has good isolation from the road. The suspension can move up and down as needed without shaking the car. The driver gets just enough road experience to be aware of any disturbing road conditions and feel the rumble strip if he pulls into the side of a freeway.

Old luxury cars, more specifically American luxury cars, have such soft suspension that the driver feels as if he is driving a boat. This is not optimal, as a sense of the road (at least a little) is necessary to maintain situational awareness while driving. Factory tuned sports cars and compact cars are often criticized for poor isolation from the road. The manufacturers of these vehicles assume that their demographic prefers fast lap times on the track over comfort on the road. In addition, vehicles traveling at race track speeds get a lot more downforce from the air, which can lead to unpredictable road-friendly suspension behavior, especially in corners.

Some possible body or ride issues to look out for include:

• Body roll: When the car body leans outward when cornering. All cars do this to some degree when cornering, but if the car's body rolls too much, the weight shift can cause the car to spin, exit the corner prematurely, or lose traction on one or more wheels. .

• Lower limit: When the tires hit the car body when the suspension is compressed. This happens when the car doesn't have enough suspension to absorb the force of the impact it's on. Fenders can prevent this by creating a cushion between the suspension and the frame that prevents the tire from rising high enough to hit the car body, but if they are inadequate or missing, this problem can occur. A rollover can easily damage the bodywork, wheels or suspension system.

How does the suspension system help the car stay on the road?

A car's roadholding ability is measured by how well a car can maintain good traction and even weight distribution when subjected to various forces. To feel stable when stopping, a car needs a suspension that doesn't allow the front end to dive down whenever the brakes are applied. Smooth acceleration requires suspension to prevent the car from squatting in the rear when the throttle is opened. Weight shifting gives half the wheels most of the traction, wasting power and causing inconsistent handling characteristics.

As mentioned above, too much body roll in corners is bad for handling. Body roll is also bad because when turning, the traction is shifted to one side of the car more than the other. This causes the inner tires to lose traction and possibly come off the road surface. Suspension that provides good traction will prevent this for the most part.

Some traction issues that can be associated with a less than ideal suspension system layout include:

• Impact Steering: When hitting a bump, the car turns left or right, but the driver does not turn the steering wheel. Poor suspension alignment can cause the wheels to lean at such an angle that this problem occurs.

• Oversteer: When the rear of the car loses traction and breaks down on a curve. If the body rolls too much in corners, weight shifting can cause the rear wheels to lose traction. This problem can also be caused by the rear wheels being at an angle that doesn't allow the tire to stick to the road enough when cornering.

• understeer: When the front wheels lose traction on a corner, causing the car to drift towards the outside of the corner. Similar to oversteer, excessive body roll or wheels with the wrong lean angle can cause the front wheels to have poor traction when cornering. Understeer is especially dangerous because front wheel drive vehicles steer and transmit power to the front wheels. the less grip on the front wheels, the less the car's handling.

• Both oversteer and understeer are exacerbated by slippery road conditions.

Suspension service

Since the main task of the suspension system is to absorb shock in order to protect the car and its passengers, the parts are made to be strong enough. There are several other components in modern cars that are just as complex as the suspension components.

However, with so much movement and force generated in the suspension, the parts will inevitably wear out or be damaged. Severe potholes can cause the vehicle to fall so hard that the struts holding the springs in place bend or break.

Creaking sounds usually accompany the failure of bushings and other connections. If one corner of the car becomes too bouncy when going over bumps, have the shock absorbers or struts checked immediately. Suspension problems should be dealt with immediately, so if the car's handling or damping changes, it should be checked as soon as possible.