There are a number of choices for suspension on a trailer that is practical and enduring and while there are other options such as swing arms, coil and shock absorber style suspension available, the following are the most popular.
Leaf Springs
Leaf spring suspension has been around in one form or another since Roman times and steel leaves have been used since the 18th century. You might think that using leaf springs on your trailer is a bit old fashioned, believe me, it’s not. The reason why is we still use them is because they are so damn good. They are relatively cheap to manufacture, long-lasting, easy to repair or replace and depending on the spring setup, they can carry huge loads while reducing stresses on the trailer chassis and axles.
Springs are built to an upper load limit and need to be matched to the total trailer and load weight. Too low a load rating and the springs will bottom out and quickly fail. Too heavy and the ride will be stiff and harsh causing stress to both the trailer and load.
Leaf springs are available in almost any combination from very light duty single leaf to behemoth 12 leaf plus monsters.
Find a spring that matches your load rating and find one that has a reasonable camber that suits your axle position. Springs are normally available painted, but galvanized leaves and also proprietary corrosion coatings are also available. Just remember that leaf springs are designed to slide against each other and wear between the leaves is inevitable and unpreventable. Galvanized springs, due to the nature of the heat treatment process may be slightly weaker overall and lose their camber quicker than painted springs.
Poorly galvanized springs are prone to cracking and failure - always purchase from a reputable supplier.
Slipper Leaf Springs
(Eye/Slipper)
This spring has the least moving parts of all springs although there can be a bit of wear where the springtail rubs against its slipper. An anti-rattle version is available as this spring can be very noisy over bumpy roads if the standard version is used. Using the slipper to retain the spring gives good lateral stability to the trailer and is especially good on a trailer with 2 or more axles because of this extra constraint. An advantage of these springs on a single axle is that the distance between the chassis and the spring is quite compact and can be helpful if you are after a lower deck height.
Double Eye Leaf Springs
(Eye/Eye)
This is another common type of setup that rather than 2 loading points on the chassis with the slipper style, the dual eye has 3 distributed points which minimize stress in the chassis and to some point to the axle. The spring requires a correct set up to ensure correct operation. I have seen these springs tuck themselves in between the hangers and jam up due to very bumpy roads and overloading of the trailer. They are ideal for single axles but due not give as good side to side stability as the slipper style on a multi-axle setup and reduces their load sharing capacity.
Another possible disadvantage is they take a bit more room up under the chassis and can limit how low the deck height can be.
Parabolic Springs
The Parabolic spring is the modern version of the leaf spring. It is normally a single leaf with a thicker center tapering out to the ends in a parabolic curve. The advantages of this spring are that there is no interleaf friction, they weigh a little less than standard leaf springs and are not as stiff as leaf springs so give a much smoother ride. Disadvantages are that they tend to take a lot of room up under the trailer so this can limit how low the deck height will be and the single leaf version has a lower load capacity compared to standard leaf springs.
Multi parabolic springs are available and these are set up with spacers between each leaf to prevent contact due to the shape of the leaves. These will take more weight but again add more to the underside of the trailer raising the deck height considerably.
Torsion Suspension
Torsion suspension is basically a swing arm style axle that pivots within a rubber or elastomer enclosure.
As load is applied to the axle the torsion arm turns within the rubber causing the rubber to compress on one side and roll on the other and as the load is released the rubber moves the torsion arm back to its original position.
This type of suspension can give a very smooth ride as the trailer rides over the bumps with independent suspension. Another advantage is that the trailer deck height can be significantly lower due to the lower profile of the torsion unit.
There are a few disadvantages to torsion suspension as follows. Torsion suspension load capacity normally maxes out at 2500 kg towing capacity as a tandem setup, but due to the independent nature of the suspension and the way it is mounted on the trailer, axle load sharing is non-existent which can stress the chassis considerably. For this reason, when mounted on a tandem trailer, the axle rating should be reduced by around 25% to avoid bearing and suspension failure. For example, over a bumpy road, one axle may be constantly working overtime while the other axle will be fully unloaded. The overloading can cause premature failure of the bearings and axle.
Pulling a trailer with the right suspension system for your application can make a considerable difference in ride quality and your overall user experience. Diamond C offers multiple premium suspension systems alongside our LIPPERT TRAILER AXLES to give you peace of mind while hauling and ensure your trailer lasts longer with less overall maintenance needed.
Picking which type of suspension system to include with your trailer is a very important decision, and varies based on which type of trailer you require for the job and what you are planning to haul. The correct trailer suspension gives you a smoother ride and protects your trailer and cargo by absorbing shock from bumps and dips on the road.
We offer 4 quality types of trailer suspension:
Keep reading to learn more about Diamond C’s trailer suspensions and which one is right for you.
(Prefer to watch instead of read? No problem – check out this informative video below from our very own Jacob Crabb, and watch and follow along as he shows several of our models up close equipped with various suspension options and gives tips about which type to choose for your specific application).
Leaf spring suspension is arguably the most common and cost effective type of trailer suspension.
This suspension design is made up of a series of curved springs (leaves) that are stacked and attached to the underside of the trailer’s axle using hangers and U-bolts. The leaf springs in this suspension system function as shock absorbers – they flex and release when you hit bumps and rougher roads, which provides you with a smoother ride.
Tandem and triple axle trailers feature an equalizer, which sits in-between the axles and links the springs together. These equalizers float to help transfer energy from one axle to another, especially while going over bumps to help soften the impact.
We offer a few different varieties depending on which axles the trailer has:
3.5K Axles: 4-Leaf
5.2K & 6K Axles: 5-Leaf Slipper
7K & 8K Axles 6-Leaf Slipper
Torsion suspension provides many benefits in overall design and function than a traditional spring suspension. The unique design of the Torsion axles includes a rubber torsion arm system that is self-contained within the axle tube, which then directly attaches to the trailer frame. The result is a far smoother ride, with less overall wear and tear on your trailer over the years.
The Torsion system uses a heat-treated solid steel inner bar that is surrounded by 4 flexible rubber cords. The wheel hub spindle is attached directly the the Torsion arm, which in turn is connected to the rubber-encased Torsion bar. As your trailer encounters bumps in the road, the up and down movement of the wheels causes the inner Torsion bar to twist back and forth. This rotating movement is simultaneously dampened and cushioned by the surrounding rubber cords, which provides superior shock absorption and gives you an ultra-smooth ride.
We offer Torsion suspension axles as an available upgrade on most of our CAR HAULERS, EQUIPMENT trailers, single wheel GOOSENECK trailers, and heavy duty series of DUMP trailers.
This suspension system is a popular upgrade among our heavier duty dual wheel GOOSENECK, PINTLE HITCH, and STEP DECK trailer models.
The Hutch Series 9700 heavy duty adjustable suspension system takes the traditional leaf spring suspension design a step further by adding several key features:
All our 16K axle equipped trailers come standard with this heavy duty adjustable suspension, including our flagship gooseneck model FMAX216, heavy duty pintle hitch model PX216, step deck model SDX216, and our dual tandem gooseneck dump model WDT (with 30K GVWR package selected).
For a smoother, quieter ride, extended trailer life, & higher rates per mile, outfit your trailer with our top-of-the-line Air Ride trailer suspension upgrade from Cush.
Air Ride Suspension utilizes airbags on each axle made from a durable polyurethane and rubber material. Dual compressors pump air into each flexible bag, enabling them to absorb bumps and vibrations much more efficiently than on a traditional spring suspension system. While spring suspensions tend to compress and release the energy from bumps into your trailer frame and cargo, Air Ride suspension absorbs the energy under the frame before it even reaches your trailer body.
We are proud to offer this premium suspension system on most of our GOOSENECK, PINTLE, and STEP DECK trailers as an available add-on. Air Ride suspension is a very popular option for HOT SHOT trailer owners who regularly haul uneven loads across long distances.
The Air Ride Package includes dual compressors, one 10V 5amp charger, and dual Group 27 continental BATTERIES.
For a more in-depth guide into this custom Cush Air Ride trailer system, READ OUR COMPLETE GUIDE HERE.
We offer a robust lineup of premium trailers – ranging from CAR HAULERS and DUMP trailers all the way to heavy duty EQUIPMENT, flatbed GOOSENECK, and STEP DECK models. All of our trailers come standard with one of these quality suspension systems, with many opportunities to upgrade on our trailer configurator.
Contact your NEAREST DIAMOND C TRAILER DEALER to view available inventory, or click below to view and price all of our trailer models.
BUILD & PRICE