How Air Bag Suspension Works

As versatile and convenient as cars are, it's easy to overlook the small built-in comforts they provide, such as smooth riding. If it weren't for suspension systems, our travels would definitely be a bit more bumpy. Air bag suspension is an improvement over the traditional systems; however, the basic design for air suspension merely replaces the parts used in the older design. A traditional suspension system involves steel springs and shock absorbers. The mechanism itself is made up of a coil, or leaf spring, that contains a piston. As the pistons moves up and down, gas or liquid contained in the chamber works to buffer the impact of the piston. This is the shock absorber mechanism at work. The spring and piston move together in each wheel position to absorb the shock whenever the car rolls over a bump. Since the coil springs are designed to resist being compressed, they further enhance the effect of the shock absorber. Air bag suspension takes this enhanced effect a couple steps further by using air bags in the place of the spring-piston setup.

Instead of the metal spring mechanism, strong rubber bags act as air containers. The bags are then connected to an air compressor and an air reservoir. The compressor does the job of inflating and deflating the bags, which is how the car gets raised and lowered. The resulting effects are a smoother ride and versatility in performance. These systems come with a control unit that's located inside the car to give the driver complete control over the system. As this set-up is just a modification of a traditional system, changing how your car performs is just a matter of purchasing a kit. Air bag suspension kits can run anywhere from $400 to $1,000, depending on how sophisticated the set-up is. The more complex systems enable the driver to adjust for different road conditions or for city versus highway driving.

Air bag suspension systems can be installed in passenger cars, semi-trailers and buses. Within the last decade they've become popular within the custom automobile culture of street rods, trucks, cars and motorcycles. These systems are more complex and feature-rich, allowing for immediate adjustments to the level or height of the car. Known as "low riders," the suspension system is much more powerful using small electric or engine-driven air compressors. The control unit enables the driver to boost up any wheel of the car at any time to the point where the entire vehicle can be "rocked" at will. Typically, these cars are using a hydraulic suspension system wherein a bladder is filled with fluid by a compressor. This device is called an hydraulic actuator. The actuator is designed to brace the wheels against the ground so the force of the fluid into the bladder will lift the car.