Coilover Shock & Spring Selection For Handling

There are two main approaches to improving the handling of an off-road vehicle: using sway bars or selecting the right shocks and springs. This article is for those who want to enhance their vehicle’s handling without relying on sway bars.

Off-Road Handling is Mostly About Spring Rate

Without sway bars, the springs and shock valving need to work in unison to control chassis roll. While rebound and compression damping play a role, the spring rate is the key factor in performance. To better understand this, think of the chassis rolling a specific distance at a set speed. Here’s what happens during a corner:

Spring compresses on the compression side
Spring extends on droop side
Rebound damping resists extension on droop side
Compression damping resists compression on compression side

Rebound damping is directly influenced by spring rate—when the spring rate increases, rebound damping also increases. In the example above, three out of the four factors affecting roll resistance are tied to spring rate. Increasing the spring rate is the simplest way to improve handling, with minimal performance loss, since rebound damping can be easily adjusted to match the new spring rate.

Design Your Springs to Use The Coilover Dual Rate Nuts

The first and most crucial step in improving handling performance is designing your springs to work with coilover dual-rate nuts. As the vehicle rolls, these dual-rate nuts engage the lower spring, increasing the spring rate on the compression side of the suspension. It’s important to carefully select the lower spring to ensure it can compress enough without becoming too stiff before the suspension bottoms out. We recommend starting with 1″ of spacing between the spring slider and the coilover dual-rate nuts at ride height, but keep in mind that tuning is necessary since every vehicle and spring setup is unique. Be cautious, though—setting the dual-rate nuts too close to the slider at ride height or using a lower spring that’s too stiff can lead to a harsher ride.

Reduce Spring Preload

Reducing spring preload increases the spring rate and can enhance handling. Preload refers to the amount of spring tension in the coilovers when fully extended. Having positive preload is essential for proper axle droop over bumps and for maintaining traction during articulation. In our article on selecting springs, we recommended a target preload range of 1/2″ to 6″. For vehicles focused on handling, it’s best to aim for lower preload values. For example, reducing preload from 2″ to 1/2″ resulted in a 19% increase in spring rate. Be sure to measure preload with both the coilovers and limit straps installed, or you might end up with excessive preload.

Choose Coilovers to Eliminate Excessive Droop Travel

Many vehicles have excessive down travel, which can negatively affect handling performance. It’s important to carefully consider how much down travel is truly needed. As droop travel increases, spring rates decrease because the springs are designed to maintain preload at full extension. In the chart below, you’ll see that reducing down travel by just 2″ resulted in a 28% increase in spring rate. The ideal amount of droop travel varies depending on the vehicle, terrain, and driver preferences, but excessive droop can compromise handling. Here are some typical droop measurements for common applications: