Careening down an old pitted road might seem like an unbearably bumpy ride, but without a suspension system on the vehicle, that same drive would be absolute bone-jarring misery. We have Newton's laws of motion to thank for this effect -- sans a suspension system, every tiny imperfection in the roadway causes tires to bounce up off the ground only to crash back down seconds later. The more imperfect the road surface, the more extreme the vertical motion becomes.
In addition, all that jumping around decreases the amount of friction between the tires and the ground. If all four tires aren't in constant contact with the roadway, then sudden accelerating, braking and cornering can spell disastrous consequences. Hard braking and accelerating toss the weight of the vehicle forward and backward, while cornering produces a centrifugal force that pushes the car outward at its center of gravity. Maintaining balance among all four tires helps mitigate problems like loss of traction and rollovers.
Enter the suspension system. This particular vehicle component didn't have to wait for the advent of engine-powered cars to gain popularity; horse-drawn carriages and coaches featured early models of modern suspension systems centuries before people hit the road in their Model Ts. Even ancient civilizations sometimes applied primitive suspension systems to stabilize their chariots and other war machines.
But roads -- from the newly paved to the old and pitted -- are nothing compared to the punishment of off-road conditions. If a modest pothole makes a vehicle shudder, imagine the impact of miles of off-roading across mountainous ridges and cavernous grooves in unending succession, each doing its best to jostle your truck like a fishing bobber on a windy day.
For more on exactly how car suspension systems benefit the driving experience, and the different components that make a smooth ride possible, explore the article How Car Suspensions Work. To find out just how punishing that latest jaunt through the woods might have been on your truck's suspension system, continue to the next page.
Rough Terrain and Truck Suspensions
Don't think rough roads are getting the last laugh. Vehicle tires and suspension systems take their toll on roadways, too, and the heavier the vehicle, the worse the damage tends to be. Tire configurations, inflation levels, pavement characteristics and suspension setups all figure into how much trouble a truck leaves in its wake.
While it can be exhilarating to traverse rough terrain, your truck's suspension system is typically a little less thrilled by the experience. Like any vehicle part, use leads to wear and tear and severe use leads to severe wear and tear. That's not to say a truck's suspension system won't last a good long time, but if a sizable portion of its travels are spent conquering off-road conditions, it's definitely less likely to last as long as a truck that maneuvers sedately over freshly paved suburban streets and super-smooth highway stretches.
Exactly how much extra damage traversing rough terrain has on the suspension system depends on a number of factors. Different suspension systems are built to optimize certain conditions above others, so one that's geared for off-roading in particular will probably help boost longevity. The terrain itself also makes a difference. The more extreme the conditions, the more the suspension system has to buck up and perform. Driving through sand or mud is likely to have a much different impact than driving over hard-packed contoured soil or rock-scattered rough and tumble landscapes.
If your truck does seem to be vibrating, knocking or jumping around more than normal -- or you're having some trouble controlling it during sharp braking, accelerating and turning -- it could be a sign that things are starting to go sour. Tire damage is one clue you can look for, as well as oil leaking from the shock absorbers. These issues are better fixed sooner rather than later, because as we noted earlier, suspension systems aren't just for creature comfort, they also fulfill key roles in terms of drivability.
For the answers to more cool questions about cars, explore the links on the next page.
Related HowStuffWorks Articles
- How ATV Safety Works
- Is off-roading bad for the environment?
- How Backpacking Works
- How Ultralight Backpacking Works
- How the American Alpine Club Works
- How the American Hiking Society Works
- How to Pack a Backpack
- How to Read a Topographic Map
- How to Use a Flare Gun
- What exercises will prepare me for hiking?
- How does wool keep you warm even when it's wet?
- Which is better for navigation -- compass or GPS?
- "Car check list before a long trip." Samarins.com. (11/23/2009)
- Cole, DJ and Cebon, D. "Truck Tires, Suspension Design and Road Damage." Cambridge University Engineering Department. (11/23/2009)
- Harris, William. "How Car Suspensions Work." HowStuffWorks.com. (11/23/2009)
- Head, Calin. "Truck Suspension Basics." Sport Truck. (11/23/2009)
- "History of Springs." PlanetSpring.com. (11/23/2009)
- Mollis, Joel. "Everything You Need To Know About Off Road Truck Suspensions -- Suspension Science." Off-Road. (11/23/2009)
- "Preventive Maintenance on Suspension Improves Tire Life." Ryder Fleet Products. (11/23/2009)
- Ryder, Bob, "Suspension Theory 101." Truckin'. (11/23/2009)
- "Shock Absorbers: Bilstein, Rancho Truck and Off-Road Shock Absorbers." 4 Wheel Online. (11/23/2009)
- "Suspension." Absolute Astronomy. (11/23/2009)
- "Suspension Problems Can Mean More Than a Rough Ride." 3D Auto. (11/23/2009)
- "The Suspension Bible." CarBibles.com. (11/23/2009)