What is car suspension and what does it do?

Ever wondered how your car manages to drive smoothly over those dreaded speed bumps and unexpected potholes? The unsung hero behind this smooth sailing is your car’s suspension system. Imagine if you could feel every slight bump and crevice on the road as each tiny imperfection sends shockwaves through the car – then imagine going over a pothole under conditions like that! Not so fun, right? That’s why car suspension is key to keeping your journey comfortable, stable, and safe.

In this blog, we break down and explore car suspension. We’ll cover everything that goes on beneath your car, which ensures your vehicle stays glued to the road and not airborne. Learn how springs, shock absorbers, and a bit of engineering all come together to turn a rough road into a smooth ride.

What is car suspension?

Car suspension refers to the system of springs, shock absorbers, and linkages that each work to provide you with both comfortable driving and better road handling. This system allows for relative motion between the vehicle and the wheels which plays a crucial role in how a car operates, how smooth the ride feels, and how well the car maintains contact with the road surface.

The importance of suspension

The primary purpose of a car's suspension system is to provide a smooth ride and ensure that the tyres remain in contact with the road. A well-designed suspension system absorbs shocks from road imperfections, maintains vehicle stability during acceleration, braking, and cornering, and helps distribute the vehicle's weight evenly across all four tyres.

Key components of car suspension systems 

The suspension system consists of more parts than what is provided below, but these are its main components:

Springs

Springs are the core of the car suspension system, responsible for absorbing and dissipating energy from road impacts. There are different types of springs used in car suspension, including:

• Coil springs: the most common type. Coil springs are typically made from heavy-duty steel wound into a coil shape. They compress and expand to absorb shock and maintain vehicle height.
• Leaf springs: often used in trucks and older vehicles, leaf springs are made of multiple layers of metal (leaves) bound together. They are robust and capable of handling heavy loads.
• Torsion bars: these are metal bars that twist to absorb shock. Torsion bars are adjustable, allowing for changes in ride height and stiffness.

Shock absorbers (dampers)

Shock absorbers, or dampers, work alongside springs to control the impact and rebound movement of the suspension. They dissipate kinetic energy in the form of heat, ensuring that your tyres remain in contact with the road and that your vehicle doesn’t bounce excessively after hitting a bump. There are several types of shock absorbers:

• Hydraulic shock absorber: these use hydraulic fluid to absorb shock and are the most common type.
• Gas-filled shock absorber: these use both hydraulic fluid and gas (usually nitrogen) to provide a smoother and more consistent performance.

Struts

Struts provide structural support to the car’s suspension system. They support the vehicle’s weight, house the spring/shock absorbers and help keep the tyres in an aligned position.

Control Arm

The control arm controls the vertical travel of the wheel, letting it move up and down over bumps and holes. This helps maintain tyre contact with the road, making it another very important component of the suspension system.

Sway Bar

The sway bar (aka the stabiliser bar) is a long curved bar that is attached across the vehicle’s body. A vehicle typically has two bars: one bar connecting the front wheels together and another connecting the back wheels. 

When turning your vehicle, the car tilts closer to the ground in the same direction that you turn - this can be dangerous because it can lead to a roll-over or a general loss of control. As part of the suspension system, the sway bar prevents this. Functioning as a torsional spring, when one side of the car tilts, the sway bar twists and pulls the opposite side of the car back down so the vehicle remains level. This keeps all four wheels on the ground and helps the driver retain control over the car.

Ball Joint

Much like joints on the human body, the ball joints in your suspension system are points on your car’s body that connect important components together in a way to facilitate movement. Specifically, they connect the control arms to the steering knuckles which helps allow your wheels to move up and down to maximise your tyre’s contact with the road, giving you more control over your vehicle.

Linkages and bushings

Linkages are the arms and rods that connect the wheels to the vehicle's frame, allowing for controlled movement, and providing stability and handling precision. Suspension bushes are rubber or polyurethane mounts that cushion the rigid components of the suspension system, including the system’s linkages. This padding/bushing reduces noise, and vibration and minimises potential damage to your suspension system’s components. Together, both linkages and bushing work to ensure that the wheels move in a safe and controlled manner.

Functions of car suspension

Ride comfort

One of the primary functions of the suspension system is to provide a smooth and comfortable ride. By absorbing energy felt from road imperfections, the suspension system minimises the impact felt inside the vehicle, making for a more safe and pleasant driving experience.

Handling and stability 

Suspension plays a crucial role in a vehicle's handling and stability. By ensuring the tyres remain in contact with the road surface, the suspension system is able to provide you better control during acceleration, braking, and cornering. This is particularly important in emergency situations where quick movements are necessary, thereby making your vehicle more safe.

Weight distribution

A good suspension system distributes the vehicle's weight evenly across all four tyres. This even distribution is essential for maintaining balance and preventing undue stress on any single tyre, preventing premature wear and potential blowouts. This helps you avoid potential tyre repairs down the line. 

Types of suspension systems

Independent suspension

In an independent suspension system, each wheel is able to move vertically in reaction to an encountered bump or dip independently of the other wheels. This type of suspension allows for better handling and ride comfort than dependent suspension, as it can more effectively absorb road irregularities. The disadvantage independent suspension presents is that it requires a complex design which takes up more space across the car. This makes it more expensive to individually maintain. Examples include:

• MacPherson Strut: a popular choice for front suspension due to its simplicity and effectiveness.
• Double Wishbone suspension: offers superior handling by allowing more precise control over wheel movement.

Dependent suspension 

In a dependent suspension system, the wheels are connected to each other, usually via a solid axle. While this type of suspension is robust and is good at handling heavy loads, it does not provide as smooth a ride as independent systems. Though with its more simplistic design, this system is more cost effective to manufacture and maintain. Dependent suspension systems are commonly found in the rear suspension of trucks and SUVs.

Can you change car suspension?

Modifying your car's suspension system is entirely possible, whether you’re looking to enhance performance, increase its height for off-roading, or are simply replacing worn-out components. However, it's essential to understand the implications and options available to ensure you make the right choice for your needs and driving habits.

Here are some reasons and options for changing your car suspension:

• Performance enhancement: upgrading to sport or performance suspension can improve your car's handling, making it more responsive and enjoyable to drive.
• Ride comfort: installing a suspension system designed for comfort can make your daily commute smoother, especially on rough roads.
• Off-road capability: lifting your suspension can provide greater ground clearance, essential for tackling off-road adventures and rough terrain.
• Aesthetic appeal: lowering or adjusting your suspension can give your car a more aggressive and stylish stance, enhancing its visual appeal.
• Replacing worn-out parts: over time, suspension components wear out. Replacing these with new parts can restore your vehicle's original ride quality and safety.
• Custom needs: tailoring your suspension to meet specific needs, such as towing heavy loads or racing, can optimise your vehicle’s performance for those activities.

How long does car suspension last?

The lifespan of a car's suspension system can vary widely depending on factors such as driving conditions, vehicle type, suspension system type and maintenance habits. If you frequently drive on rough roads, carry heavy loads or engage in off-roading, you might need to replace parts more often. Regular inspections and maintenance are crucial to ensure your suspension remains in good condition and provides a smooth, safe ride.

Get your car suspension serviced at Natrad Autocare

Get your car suspension serviced at Natrad Autocare to ensure a consistent and smooth drive all year round. Our technicians specialise in diagnosing and repairing suspension issues, using top-quality parts and the latest technology to ensure your suspension system is well-maintained. 

Whether you need a routine check-up, repairs, or an upgrade, trust Natrad Autocare to provide exceptional auto services and repairs matched with expert advice.