What exactly is the suspension system of the car or is it a bouncer?

Dictionary after dictionary simply describes suspension as “the mechanism by which a vehicle is supported on its axles.” The definition should at least recognize that it is a “flexible” system – not concrete pillars.

At the same time, everything(!) that is flexible is included – from the tire sidewall to the suspension of the driver’s seat.

Its job is to keep the wheels firmly on the ground for control, reduce noise and vibration, and compensate for unevenness in the road surface to increase comfort.

For this reason, the Roget Thesaurus lists the term “suspension” at least alongside words such as “elasticity,” “springy,” “bouncy,” “rubbery,” “stretchy,” “elastic,” “buoyant,” and “well-sprung.”

If you think it’s just springs and shocks causing this, pump up your tires to 60 pounds of pressure and sit on the ground while you drive over corrugated iron. Ggggggg – see what I mean?

Any part of your car between the road surface and the back pocket of your pants that is flexible (bends or squashes) and elastic (tries to return to its original shape after being bent or squashed) is part of your car’s suspension system.

These include springs, dampers, bushings, bump stops, body mounts, stabilizers, tire walls and more.

One of the biggest differences between a pedigree sedan and contenders for such a title is how well the balance is and how much is between you and the road.

Fine designs not only match tire size, thickness and pressure, balance the spring and sponge on the seat accordingly, and determine the optimal spring and shock absorber values, but also build layer upon layer of rubber buffers/bushings (with the right flexibility and elasticity) into the body and “suspension” mounts, the steering mechanism and almost anywhere where noise, vibration or shock could be transmitted.

If the entire system or parts of it are too hard or too soft (absolutely or relative to other components), adverse results will occur.

If the force is too great, slight vibrations and shocks are transmitted, which constantly shake and bang both the vehicle and its occupants.

If the suspension is too soft, the car’s handling can suffer. When a large bump hits the road, the flexible parts of the system are flattened – beyond their intended range of motion – causing an even more painful and potentially damaging bang.

For example, tires that are over-inflated lose grip, wear unevenly, and also act like a jackhammer on everything else.

Shocks that are too stiff not only result in a bumpy ride, but also significantly increase the shocks transmitted to their bushings and suspension, which can lead to potential body cracks. And because they tend to flex less, hot spots can form that melt their seals and cause hydraulic fluid to leak out.

Conversely, under-inflated tires can significantly attenuate small bumps and vibrations, but they wear unevenly, get too hot, are more prone to punctures, and can lead to a dangerous loss of driving precision.

Similarly, soft springs and/or shock absorbers provide a better dampened ride over smaller bumps, but the body of the vehicle tends to roll and sway more and the spring tends to oscillate, causing the tire to “hop” rather than stay on the road. This results in poor handling and braking. On really big bumps, the shock absorbers exceed their elastic limits, causing one solid object to slam into another.

The intensity of the impacts to which the car may be subjected depends on the type of road and the driving style, and even under the best regulated conditions these conditions can vary.

Suspensions are a compromise solution that covers a wide range of circumstances. A stark example is the difference between an “empty” car and one that is fully loaded or even overloaded.

It is impossible for a suspension system to optimize both.

Modern engine technology overcomes some of these problems by using “progressive” suspension – mechanisms that give slightly under light impacts but offer increasing resistance the more they are compressed.

Springs now have a “progressive” resistance to bending, the more sophisticated multi-valve shock absorbers have the same quality, and even things as simple as “bump stops” – that lumpy last line of rubberized defense that comes into play when all other parts of the system are at their limits – are usually conical, so that the thin tip compresses easily, but the harder you compress it, the thicker and harder it gets.

If your application does not fall into this compromise range, you will generally need a harder or softer suspension than average.

In an extreme case, a ceremonial limousine carrying the rear end of a VIP person at low speed in quiet surroundings might have a particularly soft suspension that could be completely inadequate at high speed or on uneven surfaces.

A rally car in the care of a capable driver required to drive down a goat path at 200 km/h would need suspension so hard that it would feel like the hammer of hell until he was… driving down a goat path at 200 km/h.

It is equally clear that the ‘normal’ average on Kenyan roads is not the same as in Switzerland or Japan and that very different assessments are required.

The bottom line is that suspension is, in many ways, one of the most important systems on your car. It affects many parts of your car, and if you manage it properly, the roads will feel better.

Flexible and variable suspension systems are a remarkable collection of interconnected inventions. And if you need to change one part of the system, the balance with all the other parts must be considered.

The consequences for you are often an either-or decision (not both), tailored to your own priorities.