Bar talk with your off-roading buddies will invariably end up discussing the optimal setup for a four-wheel-drive vehicle. Unfortunately, the loudest and most opinionated person will be the one who has installed snorkels, roof tents and has jacked his vehicle way beyond what is legal or even safe.
The most common type is an independent front and independent rear suspension setup. Coil springs enable the most articulation despite one or more wheels moving at a substantially different angle from the vehicle’s other wheels.
Most off-road enthusiasts won’t admit it, but the goal of modifying an off-roaders suspension is often simply so they can fit bigger tires. If this were the motivation, it would generally end in tears. The purpose of installing a modified suspension to an off-road vehicle is to improve your vehicle’s performance off-road.
What Suspensions Are Used In Off-Road Vehicles?
Off-Road suspension systems should have the following characteristics.
- An incorrect view is that an off-road suspension system provides a brutal and unforgiving ride. Nothing is further from the truth; a well-sorted off-road suspension should provide as a comfortable ride as possible over the type of terrain it was intended.
- The suspension should easily absorb average bumps, washboard, and rocks without leaving you needing the services of a chiropractor. The suspension system needs to rebound fast enough to maintain enough travel to soak up each bump.
- A properly designed, installed, and set up off-road suspension system should be focused on maintaining a good contact patch for the off-road vehicle’s tires.
Consider What You Want The Suspension For
Plan and decide what way you want to use the off-road vehicle. Do you want to tow the family boat across narrow tracks or travel to vacation spots that involve farm roads and rutted lanes? Most standard 4X4 vehicles are more capable than people realise.
Of course, if you want to climb up cliff faces or bounce off rocks in a way that leaves the spectators with hearts in their mouths, then you need a specialized rig.
The whole point is to invest in what you will need instead of paying vast sums of money for a capability you may only use once or twice in the vehicle’s life.
There is almost always a trade-off in another area for every modification that provides an increased capability.
- If you want to lift the car and increase the ride height, you raise the vehicle’s center of gravity and reduce the car’s stability.
- Lifting the vehicle changes the angle of the driveshaft, CV, and axle joints, increasing the long-term wear of these components.
- Big tires are heavier than their smaller diameter cousins; this means more power is needed to turn them; not only does this increase the wear on the powerplant, gearbox, drive shafts and CV joints, etc., it also increases your gas consumption. Your final drive ratio will be affected, which, if not adjusted, will reduce the vehicle’s perceived power and its acceleration capability.
- Your speedometer will register a lower speed, which may mean speeding tickets if you are not aware.
If you clearly understand what the vehicle will be used for and installing an off-road suspension system is necessary, let’s look at the different suspension setups.
Are Leaf Spring Suspensions Good For Off-Road
Although the more current solution of using coil-sprung independent suspensions offers many advantages, traditional leaf springs have a simplicity, which still makes them appealing for off-road use.
Leaf Springs are attached to both the front and rear axles and parallel to the chassis frame. The leaf springs serve to suspend the vehicle and hold the solid axle in place.
They have several advantages and disadvantages as follows.
The Advantages Of Leaf Springs
- Their simplicity makes them easy to install, repair, and upgrade. You can change the suspension characteristics by adding to or replacing some of the blades of the system.
- Leaf springs cost less than coil springs and generally are more reliable. If they do fail, they are easier to repair.
- Leaf Springs weigh more, which in terms of off-road capability is a positive as there is more contact on the ground, and the vehicle will have better traction in very slippery conditions.
- Because a leaf spring spreads the load over a wider area, they can carry a heavier weight.
The Disadvantages Of Leaf Springs
- The fitment of leaf springs means reduced approach and departure angles.
- Vehicles equipped with leaf springs are more prone to axle wrap. As power is applied, torque causes the rear pinion to pivot upward, and the rear axle housing attempts to rotate around the axles as the tires grip the road’s surface. Once the load reaches a certain point, the leaf springs begin to deform, stressing driveline components.
- Leaf springs are prone to shackle inversion, a common problem when off-roading. A shackle inversion will render the entire suspension system inoperable.
Is Independent Suspension Good For Off-Roading?
Whenever you see those YouTube videos with off-road vehicles hanging between huge rocks in crazy, almost comical poses, that is an independent coil suspension doing its job. Coil springs are giant springs that are fitted around the shock absorbers.
Arms attach the suspension to the wheel and the chassis and allow the wheel to move at extreme displacements. The coil provides most of the damping force.
Each wheel has its unit and can respond to the road surface independently of the other three wheels.
Advantages Of Independent Coil Springs
- Coil springs provide more comfort for the occupants of the vehicle. It isolates any impact of one wheel instead of being transferred through the axle to the opposing wheel.
- Off-road coil springs have a more extensive range of movement and enable off-road vehicles to cross very rough surfaces.
- Many models of coil springs can be adjusted to reduce or increase stiffness; this means they can be changed for different surface conditions.
- Coil springs enable more extensive articulation than leaf springs. From an off-road perspective, this means a better approach and departure angle.
Disadvantages Of Independent Coil Springs
- Coil springs have a much more complex suspension setup compared to leaf springs. The alignment of leaf springs is challenging and needs to be conducted by a specialist.
- Coil springs tend to be more expensive than leaf springs.
- Coil springs cannot carry the same weight as leaf springs.
Is Stiff Suspension Good For Offroad?
Earlier in this article, we commented that lifting an off-road vehicle raises the center of gravity. So, although a softer suspension setup provides better traction in off-road conditions, a stiffer suspension will help mitigate the effects of the raised center of gravity.
A softer spring setup allows a more effortless suspension movement, providing even tire-to-ground pressure, resulting in a better ride with more traction when traveling off-road.
It all comes down to the use you will be making of your off-road vehicle. A stiffer suspension will be necessary to offset the higher center of gravity if you intend to travel on forest tracks or small dunes with a roof tent or other top-heavy luggage.
If you are rock climbing or tackling dunes, a softer suspension setting will be more appropriate.
Coil springs with an independent front and rear suspension us generally the best off-road setup. However, there are circumstances, for example, if the vehicle is carrying heavy loads or maintenance facilities are far away, when a leaf spring set up would be more appropriate.
If you want to modify your off-road vehicle’s suspension, we strongly recommend that you obtain some experienced advice from someone who does not have an agenda.