Air Suspension is an important functionality of vehicles. The three most popular air suspension systems are rubber bellows air springs, sleeve-style air springs and coil spring airbags. These air suspension systems can fulfill the unique automotive demands of different customers.

1. 3 Common Types of Air Suspension
Systems
The factory-installed coil springs on your 4WD vehicle or muscle car have limited
capacities. When this capacity is reached, the rear end of the vehicle begins to “sag,” which
can cause the vehicle to bottom out and diminish driving performance.
Air suspension systems – including coil spring air bags, sleeve air springs and rubber
bellows – are designed to better distribute the weight of these loads, as well as provide a
greater level of performance controls for the driver. Yet, each type of air suspension system
provides benefits, and it’s important to choose the type best suited for your application.
For example, rubber bellows have greater lifting capacities, which is why they have been
used commercially in trucking for decades. Sleeve air springs and coil spring air bags, on
the other hand, provide greater control of driving dynamics, while also offering a solution
for load distribution. Typically, vehicles are built with a factory coil spring. Air springs are
bolted directly to the vehicle’s frame and replace the coil spring altogether, while coil
spring air bags are fitted inside the existing coil spring to provide reinforcement. Here’s a
look at each type:
Rubber Bellows Air Springs
Bellows are a common type of air spring, and this type of air bag offers several benefits.
First, the bellow is typically constructed out of reinforced rubber and has a single or
multiple chambers. The shape resembles a coffee can. Due to their larger diameter
compared to sleeve and coil spring air bags, bellows can accommodate heavier loads. Plus,
the design allows the air springs to lift heavier loads at lighter PSI pressure, which makes it
load distribution easier. That’s why bellows are typically installed on towing vehicles, 4WD
trucks and off-road SUVs.
Sleeve-Style Air Springs
Sleeve air springs are also cylindrical, but they have a smaller diameter compared to
rubber bellows. Typically, these air springs are built with reinforced rubber or a heavy-
duty synthetic rubber compound like polyurethane. The biggest difference is that sleeve air
springs are designed for lighter loads and they’re often used for adjusting ride height. For
example, in hotrod design, sleeve air springs are used to increase traction and adjust the
height of the vehicle.

2. Coil Spring Air Bags
Unlike sleeve or bellow air spring, coil air bags are fitted inside the existing factory-
installed coil spring. Thusly, the goal of the coil spring is to provide additional support to
the spring, which helps to provide better stability and more evenly distribute the weight of
the load. Instead of acting like a spring, though, these air bags cushion the spring. For
example, if you were towing a load, the coil spring would naturally push together and the
coils would get closer together. A coil spring air bag, though, expands outward limiting how
close the coils can get together.
From trailer towing, to track performance, air springs can provide a greater degree of
stability on the road and help level towing loads. Air suspension can provide a number of
benefits for drivers, but it’s important to choose the air spring best suited for your
application.
Information Provided By
Polyair Springs Pty Ltd