An air spring is an inflatable rubber device which takes the place of a steel spring in vehicle suspension systems. Often referred to as air bags, the air spring is an inflatable rubber balloon-like device. One of its first uses was on semi tractor trailer rigs and other heavy equipment. When the air spring is inflated to its maximum potential, the ride is very harsh and the vehicle is carried high on the suspension. When air is removed from the air spring, the ride becomes much smoother and the vehicle rides much lower on the suspension. An on-board air compressor and storage tank supply the air spring with air while dash-mounted as well as suspension-mounted switches activate the system, adding or removing air to adjust the ride quality.
The benefit of an air spring is found in the ability to adjust the vehicle's ride quality. If operating a vehicle with added weight, it is possible to add air to the spring and increase the vehicle's ride height. It is also possible to add or remove air from one spring and switch it to another to even up a vehicle's ride height. This is especially helpful on uneven terrain or soft and unstable terrain.
While the purpose of the air spring started out as a means of transferring weight from one semi axle to another in order to adhere to load restrictions on certain highways, the latest trend finds the system on show vehicles. Following in the footsteps of custom car designer's hydraulic systems, the air spring is the latest fad in custom car and low-rider technology. By adding air to the springs, the vehicle operates at normal ride height. By flipping a switch and deflating the air springs, the vehicle is able to be lowered until it's chassis is practically sitting on the ground.
Custom air compressors and holding tanks provide enough air at the flip of a switch to allow the springs to inflate and deflate in a moment's notice. This makes it possible for the vehicle to be bounced by rapidly adding and removing air from the springs. This is a much more mechanically reliable method of what has been termed "hopping" the vehicles as compared to older hydraulic technology.
When added to a pick-up truck's suspension, the springs allow for a much greater payload while still maintaining driveability. Whether pulling a heavy trailer or hauling a heavy load, the pick-up truck is much easier to control and operate with the addition of an air spring suspension.