What is Suspension In a Car?
Suspension is the system of tires, tire air, springs, shock absorbers, and linkages that connects a vehicle to its wheels and allow relative movement between the two. Suspension systems must support both road holding/handling and ride quality, which is at odds with each other.
Tuning of suspensions is all about finding the right compromise. It is important that the suspension keeps the road wheel in contact with the road surface as much as possible, as any road or ground forces acting on the vehicle will do so through the contact patches of the tires.
The suspension also protects the vehicle itself and any cargo or luggage from damage and wear and tear. The design of the front and rear suspension of a car can be different.
Put simply, it’s a part of a car that negates most of the forces the car receives from driving on the road and keeps the cabin quiet. It can be small rocks on the road or big potholes, the suspension can handle them.
This is a normal understanding we have that a suspension’s job is only to provide a cushion when a bump or crack occurs in the road. It does a lot more than that. Honestly, it makes a car easier to drive. What are the other things suspension does?
What Does a Car Suspension Do?
In short, your car’s suspension system is a protective lattice of shock-absorbing components such as springs and dampers. Your car’s suspension helps ensure you drive safely and smoothly by absorbing the energy of various road bumps and other kinetic shocks. In addition, it helps your tires stay in contact with the road by increasing tire friction.
To fully understand what your suspension does, you need to understand what would happen if your car didn’t have it.
When driving on the road, your car’s tires naturally roll over various imperfections and bumps. These bumps interact with your car’s wheels, applying force each time. The laws of physics dictate that any force exerted on an object has magnitude and direction.
Hitting a bump in the road, it forces your wheel to move up and down at a perpendicular angle (vertical relative to the road surface). Of course, small bumps don’t transfer much vertical kinetic energy to your car. But major road bumps or surface imperfections can transfer quite a bit of energy.
It’s common sense; When your car’s wheels hit a bump, your car gains energy and jerks up or down.
If you didn’t have suspension, all that energy would be transferred into your car’s frame. This type of energy transfer can make driving uncomfortable at best. Additionally, your car could lose grip on the road, which would cause the wheels to bounce and then slam back onto the road surface.
Your car’s suspension:
- Absorbs the energy transferred through your car’s wheels
- Helps your car cabin to ride atop the suspension relatively smoothly, even when riding on imperfect roads
The two core components mentioned above both play a crucial role in this process. The shock absorbers or dampers absorb the impulses, with the kinetic energy traveling along with the dampers instead of transferring it (at least to the same extent) to the interior of your car.
Meanwhile, the springs attached to your suspension flex and stretch to control the dissipation of this kinetic energy. They also prevent your car’s suspension from bouncing up and down too much.
Together, these two components make your car feel relatively smooth and consistent when driving.
Why is your car suspension so important?
Any modern car is equipped with a suspension due to its advantages. For example:
- Suspension systems maximize the friction between your car’s tires and the road. By maximizing friction, you can steer your vehicle more stably and experience more comfortable handling. The more contact your tires have with the road, the safer and more confident you can drive.
- Your car’s suspension system also provides additional comfort. By limiting the kinetic energy transferred to your cabin from road imperfections such as bumps, you will experience much less bobbing and your passengers will also enjoy a smoother ride.
- In addition, suspension systems can help increase the life and durability of your car. Your vehicle’s components are subjected to much less stress over time by limiting how much energy is transferred from bumps and potholes in the road. Therefore, the other components of your car will last longer.
How does a car suspension work?
A suspension works on the principle of force dissipation which involves converting force into heat thus removing the impact that force would have made. It uses springs, dampers, and struts to achieve this. A spring will hold the energy while a damper will convert it into heat.
The job of a car suspension is to maximize the friction between the tires and the road surface, to provide steering stability with good handling, and ensure the comfort of the passengers.
If a road were perfectly flat, with no irregularities, suspensions wouldn’t be necessary. But roads are far from flat. Even freshly paved highways have subtle imperfections that can interact with the wheels of a car.
It’s these imperfections that apply forces to the wheels. According to Newton’s laws of motion, all forces have both magnitude and direction. A bump in the road causes the wheel to move up and down perpendicular to the road surface.
The magnitude, of course, depends on whether the wheel is striking a giant bump or a tiny speck. Either way, the car wheel experiences a vertical acceleration as it passes over an imperfection.
Without an intervening structure, all of the wheel’s vertical energy is transferred to the frame, which moves in the same direction. In such a situation, the wheels can lose contact with the road completely. Then, under the downward force of gravity, the wheels can slam back into the road surface.
What you need is a system that will absorb the energy of the vertically accelerated wheel, allowing the frame and body to ride undisturbed while the wheels follow bumps in the road.
The study of the forces at work on a moving car is called vehicle dynamics, and you need to understand some of these concepts in order to appreciate why a suspension is necessary in the first place.
What are the parts of car Suspension?
The suspension system on your vehicle consists of the following parts:
- These are the only part of the suspension system that touches the ground.
- Coil springs. These are the part that absorbs the impact when a vehicle hits a bump in the road.
- Shock absorbers. Sometimes called the shocks or dampers, this part supports the coil spring to further reduce the impact of a bump or pothole.
- Rods/linkages. These parts work together to link different parts of the suspension system together.
- Joints/bearings/bushings. These parts allow certain components of the suspension system to make sliding actions.
Some vehicles do not have shock absorbers. Instead, these vehicles come with struts. A strut is similar to a shock absorber, as it provides support for the suspension as well as the coil springs.
MORE: What is Strut on a Car?
The steering system is also important as it works with the entire suspension system to make the car turn. The entire suspension system sits on top of the vehicle’s frame, which carries the weight of the vehicle.
Types of Car Suspensions
There are 8 Types of Car Suspensions as mentioned below:
- Multi-Link Suspension
- Rigid Axle Suspension
- Macpherson Suspension
- Double Wishbone Suspension
- Independent Suspension
- Rigid suspension
- Trailing Arm Suspension
- Air Suspension
1. Multi-Link Suspension
Multi-Link is a suspension developed by Double Wishbone and Multi-Link into a suspension that has a fairly complicated construction design because it has separate parts that are held together by joints.
This suspension also has component ends that pivot on two sides of the arm. Construction is made by manipulating the direction of the force that will be received by the wheel.
Multi-Link is a type of suspension that has a quality grip and with this suspension, controlling the car becomes easier. The Multi-Link suspension also has many variations.
If this suspension is damaged, then the replacement process takes a long time and the spare parts are still rare, so the price is relatively more expensive than other suspensions.
2. Rigid Axle Suspension
Rigid Axle suspension is usually placed at the rear of the car. The main feature of this suspension is its wheels on the rear left and right. The two wheels are connected into one axle which is commonly referred to as the axle.
The rigid axle suspension has 2 models at once, namely the Axle Rigid model which is equipped with leaf springs, and the Axle Rigid model which is equipped with a coil spring or often referred to as a spring.
This suspension has fairly good quality and can be applied in various types of cars. It is fairly simple because it can work with just one solid piece and is equipped with 2 springs.
The axle rigid is also considered a strong suspension, so it can support large loads stably, making it suitable for various types of large cars.
Suspension can help dampen the vibrations or shocks that occur when you are on a road that is uneven or tends to be bumpy. With a good-quality suspension car, you can stay seated without any disruption.
The suspension is not only useful to help reduce vibrations when the car is driving but can make handling safer and let the car can run stably on the road.
With its very significant use, of course, the suspension is a must-have component in a car and it must get extra care.
Now, there are many types of cars around the world and this makes a variety of suspension types available. Even the use of suspensions in each car brand is always different, due to a large number of quality suspensions.
Differentiating the type of suspension in each car brand is certainly a way to balance the type of car. At least several types of suspension are widely popular and used in cars produced nowadays.
3. Macpherson Suspension
Macpherson is a suspension whose name is taken from its inventor, Earle Macpherson. Lots of cars around the world use Macpherson suspension.
Many automotive manufacturers like this suspension, because it has an affordable price and also has fairly simple components.
The Macpherson suspension has an upright shape and is supported by shock absorbers which are used as the center point of the corner caster in the car. This suspension is also very easy to obtain because it’s distributed widely.
The disadvantage of Macpherson’s suspension is that it is less able to receive loads and the tilt angle always changes when the car is turned or turns, this makes the tires less able to grip the road asphalt properly.
4. Double Wishbone Suspension
Double Wishbone is a type of suspension that has 2 arms that support the suspension system, namely the upper and lower arms. With this suspension, the car can run stably.
5. Independent suspension
Independent suspension is a specially designed suspension because the right and left wheels at the rear are not connected directly but instead by axle joints
If the rear wheel steps on a hole, of course, the car will not rock and this is because only the left suspension moves. Independent suspension is indeed widely used in luxury cars.
The independent suspension has a more complex construction and the axle movements are mutually independent. This suspension is also equipped with two flexible joints. This type of suspension is still fairly expensive, so its use is mostly in luxurious cars.
6. Rigid Suspension – Leaf Spring
Rigid – Leafspring is one type of suspension that is widely applied in cars circulating in Indonesia and is mostly used in commercial-type cars or old-type cars. This suspension is usually used at the rear of the car because this suspension is stiff.
This suspension has a fairly simple and simple construction. This type of suspension usually consists of an Axle Housing that is intentionally tied using a U-Bolt already attached to the frame. Cars that use this suspension usually have a fairly high level of resistance.
7. Trailing Arm Suspension
Trailing Arm is a type of suspension whose instructions are almost the same as 3 Links – Rigid, even though the working system is very different. The way it works is also different from the 3 Links – Rigid or other types of suspension.
The Trailing Arm suspension has connected from the right side to the left. This type of suspension is usually placed at the back of the car.
8. Air Suspension
Air Suspension is one of the developed suspensions that has excellent performance, so this type of suspension is widely used in luxury cars.
Even in luxury cars, the car’s suspension can be adjusted using a computer and this allows the adjustment to be done properly.
The drawback of this suspension is that it has a very complicated construction when compared to other types of suspension. Not only that, but this suspension also has a very expensive price.
Car Suspension Warning Signs
Your car communicates when it needs attention. Some common signs that your suspension system needs a little TLC are:
- Continued bouncing after hitting bumps or a dipping when braking.
- A drifting or pulling to one side when turning corners.
- One side of the parked car sitting lower than the other side.
- Difficult steering.
- Unusually bumpy rides.
Bouncing and “nose-diving” likely indicates worn shocks. Pulling to one side could be as simple as a soft tire or the need for a wheel alignment or it could signify that some of the suspension components are wearing out.
If your car looks uneven when on level ground with one side dipping, it could mean something in the suspension system has been damaged. Steering difficulties and rougher than normal rides are indicators of system issues.
Most car owner manuals suggest the average life of struts and other suspension system parts is around 70,000 miles depending on the driver and the roads.