Air Suspension 101: Improve Off-Road Capability with Better On-Road Manners

The suspension in your car or truck does more things than it gets credit for. This is one of the least understood systems, yet plays a crucial role in everyday driving. Aside from absorbing bumps and smoothing out uneven roads, different suspension parts ensure vehicles can accelerate, brake or turn corners without too much drama. Parts work together to maximize grip through the tyres, ensuring more control, improved safety and comfort levels and that vehicles stay glued to the road.

Much of the misunderstanding is down to the complexity of varied parts, and the rise of varied suspension systems in different vehicles. Common layouts include springs, shocks and various linkages, each with separate tasks. For trucks and heavier vehicles, air suspension based around inflated rubber air bags instead of metal springs is gaining popularity, especially among the off-roading crowd and anyone dealing with heavier loads.

The Basics of Air Bag Suspension

Air suspension revolves around vulcanized air bags that replace traditional coil or leaf springs. Air pressure in the air bags can be adjusted to lower or lift the vehicle to the desired ride height. And this can be done with a flick of dash-mounted switch or in many suspension setups automatically, with height and pressure sensors relaying vital readouts to electronic management systems.

The setup in base form has existed for years, first appearing in military vehicles, and later adopted by heavier commercial trucks and buses where even weight distribution was the main priority. The advantages though have translated into other vehicles, notably off-roading-geared pickup trucks and luxury vehicles, where they increase capability over tough terrain, or allow cars to simply glide over pothole-ridden roads.

The good news is that the system and individual parts can be retrofitted to almost any vehicle. If you’re looking for improved off-roading performance, then systems based around durable, double-convoluted air bags for trucks can lift and lower all or separate wheels off the ground for increased clearance needed to get SUVs, pickups and trucks over any obstacle.

Air Suspension Components

Air bags are the main the components in any air suspension system, but don’t work on their own. Setups also consist of new or existing shocks, air tanks, compressors, air lines, a series of sensors and management systems. Let’s break down what each part does, and how the system works as a whole:

• Air bags – also called air springs or air bellows are made of thick, reinforced rubber able withstand thousands of pounds of air pressure. They straddle each wheel and attach to the chassis via top plates. There are several types. Double-convoluted bags are more common in pickup trucks, cars and vans and resemble two tires stacked one atop the other. They’re preferred in these vehicles due to their adjustability, high loading rates and shorter stroke. Heavier and bigger vehicles use thinner and taller roller or tapered air springs often deployed at the rear axle to support the additional weight of fully-loaded cargo areas.
• Calibrated shocks – to fully utilize the abilities of air bags consider separate shock absorbers calibrated for the weight and load capacity of the vehicle. This helps with compression and rebound rates when driving over potholes or other road obstacles to other much improved ride comfort and increased stability.
• Tanks and compressors – these are the lungs of air suspension systems. Compressors draw outside air, compress it and transfer the compressed air to tanks where it is ready for use. Tanks store enough air to lift one or all wheels within seconds. Smaller kits have these as a single unit, but when inflating or deflating air bags for trucks, consider separate larger, higher-capacity units for improved performance.
• Air hoses/lines – this is the plumbing that distributes compressed air to where it’s needed. Low cost air lines are made of industrial-grade rubber, but look for braided steel lines for increased durability and the reduced likelihood of punctures.
• Valves/solenoids – these parts mechanically or electronically regulate how much air gets in or out of the air bags.
• Sensors and control units – ride height and pressure sensors constantly monitor vehicle levels at the front and rear axle and air volumes in each airbag. They relay this data to control units that automatically adjust air pressure in the air bags. The parts form part of a network that also includes other vehicle systems, such as the traction control and speed radars to ensure tires get maximum grip at all times. For off-roading, mechanical systems with dash-mounted controls allow drivers to inflate or deflated air pressure in separate wheels, for instance when negotiating undulations or steep inclines.

Why Have Air Suspension in Your Truck?

Air suspension is now standard gear in most high-end car brands. Some SUVs also have this as optional equipment, but rarely will you find factory-fitted air suspension in makes and models in the more affordable price range. Regardless of the vehicle, air suspension offers multiple benefits:

• Versatility across different terrain types – lowering or lifting the chassis within seconds, or firming up or softening the ride has obvious benefits. Choose the higher ride when traversing rocky terrain, crossing streams, or when you need improved visibility. Alternately, lower the vehicle on asphalt for better fuel consumption with lower drag resistance. By varying air pressure, truck drivers can also balance performance with comfort.
• Versatility with different loads – for trucks and SUVs a major benefit is the even weight distribution regardless of the heft or size of the load. Air bags can be lifted at the rear to level out a laden vehicle, or between the left and right side, and reduce wear on other suspension components.
• Reduce vibrations and noise – reduce bounce, thumping, vibrations and noises seeping into the cabin and spoiling ride comfort. Air suspension is miles ahead in terms of adjustability, and changing ride settings according to current road conditions. This also has a direct impact on wear, especially in tires.
• Adaptability and quick installation – packaged kits are now available for most car and truck makes and models. They’re also affordable for what they offer, and are relatively quick to install.