As far as car suspension goes, leaf springs are pretty much dead and buried. But when it comes to the suspension of vans, trucks, trailers and other heavy duty, commercial vehicles, leaf springs continue to be one of the primary choices for supporting suspension.


In this article, we will look at a brief history of leaf springs and the advantages and disadvantages of the modern day leaf spring, before summarising the reasons why you would choose leaf springs for your van, truck, pickup, bus or trailer.


A brief History


As an entity, you’ll be able to trace leaf springs right back to the Roman times, where they were first created for damping chariots for when they were used on rough surfaces. For many years, the springs stayed the same, up until after the 1900’s when the first version of the shock absorber was created and then produced in mass with the Ford Model A in 1927.


Modern day leaf springs haven’t evolved a great deal. They have been developed to be more robust and hard-wearing, although the overall duty of the leaf spring and the way it functions remains the same. But what are the leaf spring advantages and disadvantages?


Leaf Spring Advantages


There are quite a few significant advantages of the leaf spring. We have listed a few of the key advantages below:


  1. The way the suspension is constructed is really simple and strong, acting as a linkage that holds the axle in position without the need for separate linkage.
  2. Extra weight and costs are reduced because of the rear axle location. This eliminates the need for trailing arms and a panhard rod (AKA track bar).
  3. Leaf springs support the weight of the chassis, making them ideal for commercial vehicles.
  4. They also control axle damping.
  5. The chassis roll can be controlled more efficiently due to the high rear moment centre and wide spring base. If the springs are mounted wider apart, the roll tendencies will be less.

Let’s move onto the disadvantages now!


Leaf Spring Disadvantages


Although there are many key advantages of the modern day leaf spring (especially when installed in commercial vehicles), there are also a couple of disadvantages which you should be aware of. We have listed these below:


  1. They aren’t always the easiest to install – but there is a clear process to follow that makes life much easier.
  2. The ride comfort isn’t as great because of the inter-leaf friction between each leaf.
  3. Over time, the springs tend to lose shape and can sag. When the sag is uneven, it can alter the cross weight of the vehicle which can affect the handling slightly. This can also change the axle-to-mount angle.
  4. Wind-up and vibration can be caused by acceleration and braking torque. The wind-up can also cause nose-diving and rear-end squat.

Before making any purchase it’s important to consider the advantages and disadvantages, especially when it comes to vehicle performance.


Why choose leaf springs?


Large layers of metal are what make up the basic anatomy of a leaf spring, meaning they can deal with huge vertical loads. They offer a huge amount of support between the wheels, axles and the vehicles chassis, making them perfect for commercial vans, pickups, trailers and trucks, where the need to support greater weights is essential.