Matt Kimberley profile picture Matt Kimberley 5 months ago 10

Are We All Using The Term ‘Shock Absorbers’ Wrong?

Shock absorber is term often used to describe the dampers in car suspension, but that’s technically all wrong…

Remind me later
Are We All Using The Term ‘Shock Absorbers’ Wrong? - Tuning

It happens all the time. Words that are technically incorrect get adopted by so many people that they become accepted, maybe even normal. The first cars were called horseless carriages until 1895, when Britain adopted the more fashionable ‘motor car.’

Sometimes, though, a commonly used term relates to a point of technical accuracy and it’s annoying to get stuff like that wrong. It always helps our understanding of a subject, and our ability to communicate it, if we try to use the proper terms. And hell, we’d be the first to admit we’ve fallen into this particular trap plenty of times. We’ve already covered how intercoolers aren’t actually intercoolers at all.

Shock absorber, or just shock, is often used to describe a damper in a typical car’s suspension setup. It’s one of two key components in the bounce process; the other being a spring normally made out of a steel alloy. You can read more about how dampers work in our main feature.

Are We All Using The Term ‘Shock Absorbers’ Wrong? - Tuning

When you think about it, though, the damper isn’t the component absorbing the shock. That would be the coil spring. The coil is the part that reacts to impacts; the part that absorbs shocks. The damper’s job is to slow that motion and make sure the car can place an even load on each tyre at all times – or at least as even a load as circumstances will allow.

A more technically correct alternative name for dampers could be bounce absorbers or spring controllers, but neither is as neat and tidy as dampers so we’ll stick to that. In the words of Greg Kirby, Eibach’s General Manager:

“A spring accommodates imperfection and supports the vehicle. A damper’s main role is to control the motion. If you didn’t have dampers the car would pogo along the road and, in extreme, you would have wheel hop.”

On the face of it you’d assume that manufacturers painstakingly select the right combination of springs and dampers to get the best feel for the particular car. If the CT office’s combined road testing experience is anything to go by, that’s about as accurate as a pub darts champ after eight pints and a whisky chaser.

Sometimes a car feels too eager to blow through travel. To fix it you’d need stiffer springs, but also more damping. When a car jars over harsher bumps but otherwise rides nicely it’s because the compression damping is too restrictive; there’s too much of it. If a series of small, sharp bumps gradually eliminates your spring travel then the rebound damping is too heavy. One or more of these problems are common in all kinds of cars.

Bilstein makes very well regarded dampers
Bilstein makes very well regarded dampers

One solution to a mismatched ride is coilovers. These combined springs and dampers are readily available for almost all makes and models of car, and these days they’re built by everyone from bargain-basement ‘brands’ operating off the back of cheap labour to high-end brands that regularly prove and develop their gear through punishing motorsport. Always choose the expensive stuff if you can.

Coilovers are built as matching items, where the spring rate and the damping are tuned to each other – as well as for the size and weight of the cars they are meant to fit. The best ones come with degrees of adjustment to allow you to fine-tune the way they behave in your preferred style of driving. What’s more, you always know that if they’re set up properly, they’ll always give you the best balance of ride and handling. Just don’t call the dampers ‘shocks’…