Kevin Boden Tyre Sales

Shock Absorbers

Try this simple ‘bounce’ test. Press down on one corner of your car and let go. Count the number of bounces before the car comes to rest. If the car bounces even twice, your shock absorbers are faulty and should be checked straight away.
An important part of the suspension is the shock absorbers, these are usually hydraulic or gas filled. They are essential to control the bounce on the vehicle and to ensure the tyres are kept firmly on the road. Damaged and worn shock absorbers can reduce the braking efficiency, cause poor cornering and tyre wear.

Worn shock absorbers not only reduce driver comfort; they can also dramatically affect the handling and safety of your vehicle.

We supply and fit a large range of car shock absorbers, all at competitive prices. Kevin Boden Tyre Sales can supply standard shock absorbers as as well as sports shocks. Our fully trained mechanics will be happy to inspect your shock absorbers - completely free of charge! If necessary they will also offer you replacements from our extensive choice of top brand names - all fitted quickly and professionally !


What do shock absorbers do

Essentially, shock absorbers do two things. Apart from controlling the movement of springs and suspension, shock absorbers also keep your tyres in contact with the ground at all times. At rest or in motion, the bottom surface of your tyres is the only part of your vehicle in contact with the road. Any time that a tyre’s contact with the ground is broken or reduced, your ability to drive, steer and brake is severely compromised.

Despite popular belief, shock absorbers do not support the weight of a vehicle.


Heavy Duty Shock Absorber

Types of Shock Absorber

Although all shock absorbers do the same job, different types of vehicles and suspension designs require different types of shock absorbers which can appear radically different.

No matter the application, all shock absorbers fit into one of three broadly defined types – conventional telescopic shock absorbers, struts or spring seat shocks


Conventional telescopic shock absorbers
This is the simplest type of shock absorber and is generally replaced rather than repaired. This type of shock absorber can be found on both front and rear suspension systems and is relatively inexpensive
Strut type shock absorbers
Although they do the same basic job, struts replace part of the suspension system and must be more ruggedly built to cope with greater loads and forces. Although most commonly seen on the front and rear of small to medium cars, larger cars are now tending towards strut based suspension design. The strut category is further divided into sealed and repairable units. As the name suggests, sealed units are designed to be fully replaced, whilst repairable (McPherson) struts are able to be fitted with replacement strut cartridges
Spring seat shocks
The spring seat type shows characteristics of both telescopic and strut type shock absorbers. Like struts, a spring seat shock is a suspension unit and damping device in a single unit. Unlike struts however, they are not designed to be subject to high side loads. Built using similar components to conventional shock absorbers, spring seat shocks are also sealed requiring full replacement.

Shock absorber are attached at the end of the piston rod and works against hydraulic fluid in the pressure tube. The movement of the suspension up and down force the hydraulic fluid through minute holes inside the piston. However only small amount of fluid is forced inside the piston. The insertion of fluid reduce the speed of the piston which in turn slows down the piston, which in turn slows down spring and suspension movement.

The speed of the suspension and the number and size of the orifices in the piston determines the resistance a shock absorber. Nowadays, shock absorbers are made using this principle. That is faster movement of suspension means more resistance shock absorber provides. Shock absorber designed on this basis simply reduces the bounce, Roll or sway and Brake dive and Acceleration squat.
Shock Absorber Working Principle
There are two cycles in which Shock absorber works:
Compression Cycle
In the compression cycle the piston moves downward and compresses the hydraulic fluid in the chamber which is situated below the piston. In this cycle or downward movement, the fluid flows to upper chamber from down chamber through piston. Some of the fluid also flows into reserve tube
through the compression valve. Flow is controlled by valves in the piston and in the compression valve.
Extension cycle
In the extension cycle the piston moves upwards toward the top of the pressure tube. The upward movement results in the compressing of the fluid in the chamber lying above the piston. The extension cycle generally provides more resistance than compression cycle.


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