Get the best suspension for your heavy-duty needs. Know the pros and cons of air springs and leaf springs to determine which one is best for you.
Get the Best For Your Needs
The most common reason many truck drivers spring for pneumatic (air) suspension is overall ride quality. Ride comfort helps make those long hauls more pleasant but also improves your overall safety. Air suspension systems are designed and engineered for cushioning the ride, ensuring it is smooth and consistent. As you know, a smooth and cushioned ride is beneficial for your vehicle and cargo.
Alternatively, leaf springs have the reputation for spreading the load weight more evenly over the vehicle’s chassis. They are durable and dependable, which is often why drivers with shorter trips and heavier hauls still choose them. Because of their design and location on the axle, they also eliminate the need for trailing arms and track bars, resulting in less weight and cost savings.
These are just a few reasons why some people choose one suspension system over another. But before you make a decision to buy, let’s discuss in more detail as to why you may opt for one over another.
Pneumatic (Air) Suspension System Hx
Air springs (air bags or air bellows) made their debut in America back in 1901, thanks to William W. Humphreys. Even though they have been around for ages, innovators and experts continue to improve on their design and functionality. Early versions were quite simple. Air springs replaced coil springs. The bag was then inflated to the optimal pressure or height with a common compressor via a valve on the bag.
Much excitement over air springs in the custom automobile culture – street rods, race cars, trucks, and motorcycles. They sometimes incorporate more radical air suspension setups utilizing high-pressured industrial gas bottles (nitrogen or carbon dioxide).
However, the trucking industry has been revolutionizing air springs for decades, customizing suspension cushion specifically for heavy loads and various ride terrain. As innovators became more tech-savvy, the use of more components and controls were added to complete the air suspension system. Some of these components may include:
- Mounted compressor (an electric pump pushing air into the bag)
- Air lines (move the air from the compressor)
- Air drier (removes moisture from the air, often with a desiccant)
Air Spring Identification
Air Spring Design | Which One Should You Use
Today, most air springs have three basic shapes. They are the bellows, the tapered-sleeve, and the rolling-sleeve.
Air Spring Basic Shapes
- Bellow style air spring are configured with either one, or multiple convoluted chambers. Bellows air springs are typically larger than sleeve style air springs and can lift with greater force at lower air pressures. Popular bellow air spring configurations include the following: single, dual and triple chamber designs.
- Tapered sleeve air spring is sleek, slender in shape, which makes it the ideal bag when the area offers little space. This design allows for additional adjustability on ride height.
- Rolling sleeve air spring is a specific-application airbag. Depending on the application, this design optimizes ride height and spring control.
Air Spring Type Benefits
- Double-convoluted air springs generally have more load capacity, a shorter stroke, and a more progressive spring rate. It’s ideal for use on most front suspensions. Since the spring sits considerably inboard of the suspension’s load point, it is efficient for multiplying load-capacity requirements and numerous travel requirements.
- Tapered sleeve and rolling sleeve air springs generally have a longer stroke and a more linear spring rate. This makes them ideal for most rear-end applications. This is typically due to the travel necessities and fewer load-capacity requirements.
Why You Want Air Springs
- Driver comfort and safety
- Less damage to application, cargo, and roads
- Less load shifting and damage
- Load versatile, wide spring rate and load capacity
Driver Comfort and Safety
Truck drivers clock in long hours over countless highway miles, rough terrain, and unforgiving asphalt. Fatigue and discomfort have led to many accidents over the road. By reducing these harsh elements, you can experience a safer, more comfortable ride. Reducing noise, isolating vibration, and eliminating harshness of the ride whenever possible, driver fatigue is lessened. Safety is improved.
With air suspension, drivers can choose a softer ride for cruising along a well-maintained interstate or opt for a harder ride with added handling benefits when the road terrain is more demanding.
Less vibration is great for driver comfort, but it also means that it’s easier on the road, bridges and even nearby buildings. Fewer vibrations are transmitted which means less damage.
It’s also better on your vehicle’s components too. The reduction in vibration can lead to longer trailer life. This means those wearable parts like shock absorbers, height control valve, airline hoses and fittings, etc., may have a longer lifespan. This can save you time from fleet downtime and money accumulated from repairs.
Quick Tip: Air-Ride Suspension Maintenance Guidelines, states that air springs should be inspected every 50,000 miles.
Benefits for Truck and Trailer and Components
- Reduces cab, truck body, and trailer damage
- Reduces electrical repairs
- Reduces wear on tires, axles, and transmissions
- Reduces damage to hinges, lights, rivets, and trailer hardware
Less load shifting and damage while in route
There is only so much that packaging and load restraints can do if your suspension isn’t up to snuff. Less vibration throughout the suspension means that there is less likely to damage the cargo you are carrying. For loads that have shifted, or when cargo weight cannot be loaded evenly, air springs can help the vehicle adapt to terrain and turns.
When hauling fragile loads, like glass, many drivers choose air springs because there is less risk of cargo damage. Additionally, with unladen trucks or when you are carrying a light load, some air suspension systems can optimize ride height (lowering your ride height), thus improving aerodynamics and keeping a consistent ride.
Leaf Spring Identification and Measurements
Leaf Spring Design | Which One Should You Use
Leaf springs consist of long, metal strips. Typically, there are three-five but can consist of more depending on the capacity requirements. They are stacked on top of each other, creating an inverted arch with the longest strip on top. These strips are held together by a center bolt and bound together with clips in quarter-length intervals. It is common for the top springs to curl upward to form circles (eyes).
Why You Want Leaf Springs
- Longevity and durability
- Load handling
- Cost savings
Made to Last
Leaf spring suspension is more durable than air suspension. It’s common to see the factory leaf spring in a vehicle that’s half a century old. Leaf springs are durable and don’t require much maintenance. At Wheelco, we encourage proper maintenance to be conducted according to manufacturer’s specifications.
Common reasons for leaf spring failure
Leaf springs failure does happen. They can crack, corrode or break. Common reasons why include:
- Improperly torqued U-bolts and break a leaf spring. It is common that they are not tight enough.
- Corrosion is common if you drive salted roads or drive in areas where corrosives are involved.
- Overloading your truck and break leaf springs. You may see radial shearing or broken/distorted spring eyes when this occurs.
#WheelcoQuickClips: How to Measure Your Leaf Spring
Need to replace your leaf spring? Here’s a How-To Video showing you how to measure your leaf spring.
Load Handling Benefits
Heavy duty leaf springs significantly reduce sagging, wheel-hopping, swaging and squatting. Leaf springs make your ride more stiffness to your ride, therefore you’ll have better load handling. You are sure to notice when your load is full or if you are driving empty.
Lower Costs and Fewer Components Required
Air suspension tends to be more expensive than leaf suspension. This is due to the many wearable parts and materials used to build the components. Additionally, the labor costs to install and fix are often more. Hose installations, fitment of air suspension—there are several mishaps that can occur if you are planning to install air systems yourself. We recommend this be done by a professional/knowledgeable mechanic. It’s also important to consider that warranties are often void if the parts weren’t installed properly.
If you are looking to upgrade or replace your suspension, we are ready to help you. Likewise, if you would like additional help determining the best suspension system for your heavy-duty vehicle, we can advise you to which would be the best system. Our experts are knowledgeable in suspension and can give you expert advice as to which suspension system would best be tailored to your specific needs.
Check Out Stemco’s Air Spring Features!
STEMCO SUPER CUSHION® ROLLING LOBE AIR SPRINGS3 Year Warranty
We back our air springs with a 3 year warranty. Whereas competitors only offer 1-2 year warranties.Superior Rubber Chemistry
Chemical additives infused into rubber walls provide ozone resistance, resulting in less flex-cracking and longer life.Fuel-Efficient
Innovative materials and design weighs less than competitive products, which means more miles per gallon.Bracket Dimples
Non-elongated design provides a more secure mounting for the air spring, increasing longevity and reducing vibration and misalignment.Internal Wall Cord
High-strength, extra-tight cord provides exceptional wall and internal splice strength.Comfort & Longevity
Reduced driver fatigue and increased safety. Improved vibration isolation reduces wear on truck & trailer.
What are the Top Brands in Suspension?
Wheelco recommends using brands like Stemco, Goodyear, and Firestone for air springs. If you are buying leaf springs, we trust Triangle and Dayton.
Suspension Service Centers
With many full-service centers, our service technicians regularly work on suspension systems. If you need installation, maintenance work and/or repair jobs, we can help. Simply give us a call or stop by one of our stores.