What are shock absorbers and how do they work?

What are shock absorbers and how do they work?

What is a car shock absorber? ➤ How shocks work? ➤ What types of shocks should you invest in? ✅

What comes in your mind when you hear the term shock absorbers? For many, it is all about being comfortable in the car. Well, there is truth in that, considering no one want to reach at the destination feeling like they had been carrying a very heavy load.

No one will want to reach wherever they are going feeling bad from numbness after long hours on the road. You want to still feel fine even after riding on an uneven road.

Have you ever wondered what may cause such a situation? Many people who love travelling can talk of a smooth ride when they get wherever they are going without pain in their bodies.

Now imagine riding at the back of track on a rough road? By the time you are alighting, chances are you will be feeling great pain all over your body.

The reason for this pain may come down to the suspension system in your car. One of the main components of these systems is the shock absorbers. It is a very important component that you cannot afford to miss.

It does not only apply to cars but to other automobile like motorbikes. Whatever means of transport you are using, using a shock absorber.

There are shocks exerted on the body even when you walk or run. The shock is transferred from on part of the body, for instance the feet to other parts through the nerve system. This is why a shock absorption system becomes very vital.

The shoes you wear for example are designed with shock absorption material. This ensures your foot lands comfortably on the ground.

When it comes to car, shock absorbers are included as part of the suspensions system. If you look under the wheels of your car, you should see parts that look like springs. In essence, shock absorbers are just springs.

There are different types of shock absorbers in the market today. For instance, there are twin-tube and monotube absorbers. There are also absorbers that feature “remote” fluid reservoirs. If you have no idea of what this means, you are at the right place to learn, continue reading.

What is a car shock absorber?

A moving car can be dangerous even from the inside. As the body moves up and down, you can feel very tired when you reach your destination.

However, a car is fitted with car shock absorbers. This is part of suspension system responsible for slowing and stopping, and up-and-down movement. They have a great impact on the movement of your car’s springs. Perhaps you have heard of dampening before. That is the concept of these components.  

Springs extend a lot every time a car goes through a pothole. Without shocks to keep things calm in the suspension, springs would not stop extending. They would continue to release energy absorbed from the bumps on the road without any control. As much as we need the springs to absorb the energy, it is important to have some control on the rate at which they do this.

Too much expansion dissipates the energy absorbed by the shocks. Well, you can just imagine how much a bouncy ride you would have in the end. Your whole journey will be ruined as a result. You need to have your shocks working at all times to avoid getting into such awkward situation. You will not be able to steer your car effectively on a rough road.

A better view of how shocks work

Scientifically speaking, shocks ensure there are no unwanted motions on the springs. As the spring produce kinetic energy, the shocks convert it into heat. In other words, when you apply breaks on your car, the kinetic energy that is supposed to push your car forward becomes the heat that helps your car slow down and eventually stopping. Another reason hydraulic fluid is important in your car is to channel the heat away.

The aim of shock absorber working proper is to ensure your vehicle’s ride is made steady. The centre of gravity is stabilized at a central location. This helps the tires to hold firmly on the ground. As a result, you have the best control of your vehicle at all times.

There are no denying shock absorbers are among the most important parts of your car. They ensure you don’t even feel the small portholes on the road.

Each type of vehicle is designed to hold a different set of shock. In big vehicles for instance, shock absorbers are designed to hold the extra weight from the load. In smaller car on the other hand, the shocks are light enough to handle your weight.

It is important that you understand how these components work. There are basic design variations that exist and won’t be hard to anyone to understand. Once you have a clue of what they are, you can have a more informed decision when it comes the time for changing the parts.

A design to handle the pressure

To better understand how this part works, it is vital to know how they are designed. If you check between the frame of your vehicle and the suspension, you should see the shock absorber. They are part of the same system that are placed near each wheel.

Shocks have two mounting points:

● The eye. This part is described as the eye because of how they look. They are round bushing in which the bolt passes. You can actually see they are eye-like openings.

● The pin. This is the threaded shaft that receives the nut. The part looks like a pin and hence they are described so.

The real shock absorber working principle is defined from the inside of the shocks. There is a metal rod attached to a piston which moves up and down inside a cylinder. The cylinder also contains the hydraulic fluid that absorbs the heat.

Modern shocks are so much better than the classical ones. There has been great improvement. You can see this based on the type of fluid inside the cylinders. Contemporary ones have nitrogen gas as well which keeps the shocks free from wear, when the oil becomes aerated. This happens when heat builds up, making the oil bubbly, which may really affect the general performance of the shocks.

They also contain a piston that moves up and down, enabling the vehicle to move smoothly. When you wheel hits a bump, the piston compresses inside the cylinder. This compression causes slowing down of the motion as an effect from the resistance of the hydraulic fluid. The fluid works its way out through the specially designed passages in the cylinder wall. There is very limited amount of fluid that escapes though because the openings are very small.

He springs would continue bouncing if there were no way of controlling it. This would in turn affect the way your car absorbs the bumps.

Shocks work by producing resistance, of which most comes from the extension cycle. This is where the suspension gets longer and the compression cycles in which it becomes shorter. The compression cycle is responsible for unsprung weight regulation in the wheels, axles and suspension. On the other hand, the extension cycle handles the sprung weight from the car’s body.

One of the major developments regarding these suspensions is that modern ones are designed to vary and increase resistance. When the springs and shock absorbers are compressed faster, there is better control and reaction from the general design of the shocks. This effect works on preventing bottoming out over deep potholes. Otherwise, there would be too much unwanted body motions.  

Are you still wondering what is shock absorber? Well, let us look at other aspects that can make it easy p understand the true meaning of shockers.

Another perspective of car shocks

All shocks contain hydraulic fluid. This is the fluid that enables the piston to move smoothly inside the cylinder and enable proper functioning of the system.

However the layout of gas charged and hydraulic shock absorbers is quite different. On one side, the gas charged ones offer a firmer, sportier ride. They contain a high pressure gas (nitrogen), which is injected inside the shock. Even the way they are designed appears very different from the latter.

The pressure from the gas compressed the air and oil inside the shocks faster. As a result, you get a more responsive feel when riding on any terrain. Many people prefer this type of shocks in their cars especially those who ride for long.

● Hydraulic shocks work a bit slower. The air and the oil are not under so much pressure. This makes them to operate a bit slower because the compression is not very first. Hydraulic shocks are still very efficient in terms of giving you a softer and smoother ride.

Deciding which shocks are best for your car depends on the car you have. If your car is classic, it was probably designed to hydraulic shocks.

● Other difference between these two types comes in regards to prices. As you can imagine, a high performing gas shock absorber will be higher in price than a hydraulic one. But if you want to get the best performance for your car, you will not mind investing in the best shocks on the market.

With so many products on the market, it is important to understand the needs of your car. Any type can serve you great depending on where you are.

A more Technical look

As seen above, shock absorbers from different brands may seem different. However, there are two main types:

The mono-tube

These layouts are easy to understand, simply from how they are described. The main difference is in the number of tubes found within each shock absorber. The outer housing is the sole cylinder tube for everything. It holds the hydraulic oil, gas, valve, and other component. The nitrogen gas is contained in the main cylinder, which is a different case with the twin-tube design. A floating piston is used to separate the gas completely from the oil.

In essence, one of the main advantages of such shocks is low aeration. Then there is low operating temperature as a result of more fluid space. This encourages use of more fluid to absorb the heat. The result is a more stable damping force generated without fade.

These shocks provide a great chance to be mounted at extreme angles. Unlike the twin ones, this is gives you an opportunity to be creating in installing the shocks. This type of shocks is ideal for aggressive driving. The gas needs to be constantly at higher pressure.

But this is also a disadvantage, considering high pressure can be hard on the seals. A physical damage on the outer shell will affect the whole system, making it impossible for use. This is because there is no squish room between the casing and the piston cylinder walls.  

The twin-tube

This one comes as OEM equipment because they are more compliant, comfortable and with low production cost. On the other hand, mono-tube is more about performance driving but they are more sophisticated, making them a bit more costly. In this type, the piston is in a small tube with a larger outer one. This is where the name twin comes from because it has two tubes. Because it has two tubes

The inner tube is referred to as the pressure tube while the outer is known as the reserve tube. A valve located between the tubes separates them into two chambers. This is a very important part that protects the shock absorbers from damage. In essence, anything that happens on the outer tube will not affect the inner one.

There are however more chances of fluid aeration since nitrogen gas and the fluid are not separated. This might happen under heavier use conditions like driving off-road or in a race. To prevent this from happening, there is a valve that allows fluid and gas to pass. The gas therefore is kept at a low pressure, producing a better ride all the way. This feature ensures the seals run for a longer time.

The piston valve is much smaller here. This is because of the limited space generally created. Another disadvantage is that it is loaded with a limited oil capacity. Let us look at each type separately.

The road and the shocks

 Another type of shocks to get when going off-road is the shocks with remote reservoirs. The extra reservoir gives you extra capacity for more oil and nitrogen gas.  

These shocks with a capacity to take extra oil and nitrogen are another variation making their way into the market. There is an extra fluid reservoir that serves as extra capacity. It is either attached or detached from the main shock tube.

Heavier vehicles used for off-road purposes and fitted with huge amounts of wheel travel find these shocks quite useful. The vehicles face high impacts that would easily get standard shocks overheating. The extra hydraulic fluid absorbs the extra heat, giving the shocks great functionality.

The fluid is enough to keep things cool while more gas in means better compression and rebound valves. What you get is consistency under even the most severe conditions. This gives you better handling to avoid dangerous situations.

One good example is the “piggyback” style shocks. They are built with reservoir canister mounted directly above the body of the shock absorber. A true remote reservoir comes with a separate reservoir mounted in a different place in the car’s frame. They all perform at the same level though, irrespective of the distance of the reservoir.

These suspensions are better used on the rear wheels since they take on the most pressure. There are many different manufacturers or both piggyback and true remote reservoir shocks. All you need is to identify one that has what you are looking for.

What types of shocks should you invest in?

When it comes to choosing the right type go absorbers, it depends on how much you use your vehicle. For those who go racing for long distances for instance, it would be a good idea to get high-performance mono-tube shocks. There are chances of brake rotors, pads and calipers going above 1800 degrees F. Before you finish the race, your shock absorbers will take too much heat they won’t function anymore.

The benefits of using mono-tube shocks can never be over-emphasized. The high temperature resulting from racing has a direct impact on your shocks, something you may want to avoid at all costs. Mono-tube shocks have the ability to dissipate heat more effectively. The cool condition keeps performance high. There is no fluid aeration, which prevents some squishy surprises.

When riding on a smooth-paved, flat surface, you may want to consider the shorter stoke.  This is typical for mono-tube shocks and will getting riding fast and long without any worry.

The best time to replace your shocks

It is obvious however good your shocks are they won’t last forever. It will come a time when you will need repair or replace the ones you have. One good reason to get replacement shocks is when there is fluid leaking and worn brushings.

Sometimes however, shocks and struts starts to deteriorate without showing external signs. A shock absorber can easily flex after a few miles. This is why you will need replacement just after 50,000 miles.

The best way to know when a problem has arisen is by to;

● Judge the integrity of your strut or shock performance. You might have noticed your vehicle riding harshly, or nosedives when braking. This is an indication you have issues with your system. Apart from the, the car may be rolling excessively during corners or bottoms out on bumps.

●  Another good parameter is uneven tire wear. This happens because one side is taking on more pressure than the other. In such a case, you need to get new shocks or struts.

● Sometimes the signs of worn shocks can be easy to notice. But you can miss on them as well where the effects don’t come until after a long time.

Consider for instance when your vehicle experiences a dip when you are braking. You should replace the shocks both front and rear. Notice as well, if strong winds make your vehicle to veer from one side of the lane to the other.

Does your vehicle bottom out easily like there is no squish? You need to get new shocks.

Cupping is another obvious sign. This is a type of tire wear that happens when the shock absorbers are not keeping the tires flat on the road. Consider replacing the front and rear tires in pairs.  

What are struts?

You might have notice we have mentioned struts all through this guide. This is because the two word are inseparable. These are two terms used interchangeably, though wrongly on most occasions, by different groups of people.

Shock absorbers can be either mounted on the vehicle as a separate component or be part or a strut assembly.  Struts perform a very important task in the assembly of a vehicle’s suspension. They offer a mounting point for the hub/control system while combining the shock with a coil spring. They also support the wheel tire.

Struts in the modern cars are put on the front wheels. Shocks go to the rears. Classic vehicles have struts in both front and rear wheels. Other cars may only have shocks and not struts.

Different cars have different requirements in this regard. But you cannot replace struts with shocks. Consider what your car needs and use that when doing replacements.


Understanding how your car shocks work is the best way to achieve proper car maintenance. You will be able to tell when your car needs new shocks and how to pick the right ones.

It does not matter the type you get. Whether you go with performance oriented or OEM-quality ones, you will get a great ride, and that is what matters.

We have tried to go dipper with on the definition of shock absorbers so that you get all the knowledge you need. Now you are ready to bolt up a new and restore your ride to the best status.


RELATED ARTICLES View all articles