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… And Why You Should Probably Upgrade Your Suspension as Well

The Vehicle is Over 1,000 Pounds Heavier Than Stock

Ensuring your vehicle is properly sprung for the amount of weight you carry is the most essential part of any aftermarket suspension setup for overlanders. High-performance off-road springs offering the last degree of available articulation might be great for a lightweight rock crawler, but for a build like my GX 460 overland build where I’m carrying a lot of gear, they are not ideal. Things like heavy-duty front and rear bumpers, a winch, drawer system, roof rack, outdoor adventure gear, recovery gear, and the ubiquitous 12V fridge filled with icy-cold craft beer are just a few of the things that come with me everywhere.

Icon Vehicle Dynamics Air Bump Suspension

The first thing to consider upgrading on any overland build is appropriate springs for the loaded weight of the vehicle. For my GX 460 project the obvious perfect choice was ICON’s dual-rate 3-inch Overland Series rear coil springs. Because I’m often incorporating paddlesports, mountain biking, and skiing—and all the accessory weight that comes with those activities—into my overland travels, it was absolutely essential that I use a spring that offers the high-speed off-road performance I wanted and the load-carrying capacity I needed.

The result is a vehicle that handles well and is fun to drive on the street, but also a truck that doesn’t shy away from carrying heavy loads over rough terrain at speed. I decided to take it to the next level and install a set of ICON’s hydraulic bumpstops as well, which are essentially small shocks that absorb very harsh impacts. The increased bottoming resistance these give me offers a lot of peace of mind when I inevitably hit a rock or a washout going just a tad too fast on the dirt.

Going Fast Off-Road in a Relatively Heavy Truck

Driving through dirt ICON Vehicle Dynamics 2.5-inch remote-reservoir shocks

So now that we’ve properly sprung the vehicle for the amount of weight we’re carrying, it’s time to control those springs and ensure the vehicle doesn’t dance around. On a heavy vehicle that sees a lot of time in the dirt, it’s important to be concerned with overheating your shocks. The best way to mitigate that is by adding more fluid volume. My ICON 2.5-inch remote-reservoir shocks have three to four times the amount of fluid that my factory shocks had. More fluid means more thermal mass, which means when I’m bombing down remote corrugated roads, I can push the limits without worrying about shock fade and lost dampening performance. Because I don’t constantly drive around town with a fully loaded vehicle, I opted for shocks with ICON’s Compression Damping Control Valve (CDCV) technology. Small adjustable dials on each shock’s remote reservoir allow me to fine-tune the compression with ease. It’s a really handy feature to have this ability if you use your vehicle in a wide variety of ways and the weight fluctuates significantly. You can have a smooth ride with this setup no matter the terrain or vehicle’s payload.

Correct Geometry for a Lifted Vehicle is Essential

When you lift a vehicle, the geometry of your suspension components can change drastically. Those of us with independent front suspension (IFS), like my GX 460 uses, have a few more things to pay attention to. With IFS, it is essential to correct your suspension’s geometry when you lift the vehicle, otherwise it will handle poorly, and you’ll be wearing out tires faster than Tokyo Drift.

ICON Vehicle Dynamics Suspension

Upper Control Arms (UCAs) control the caster and camber of your vehicle’s frontend alignment. They also play a significant role in deciding the wheel travel you’ll get out of your system. On an IFS vehicle, the amount of total wheel travel seldom changes regardless of how much lift you have. If you have 10 inches of total wheel travel, you’ll usually have around 5 inches of up-travel, which is important for absorbing impacts, and around 5 inches of down-travel, which is important for putting traction to the ground. When you lift an IFS vehicle and retain the stock UCAs, you are typically going to be sacrificing down-travel while increasing the angle of your control arms. Both of these things reduce ride quality and impact absorption.

ICON Vehicle Dynamics Stage 7 suspension kit

On my GX 460 build I went with ICON’s Stage 7 kit, which offers a holistic package of quality suspension components. This system includes tubular UCAs that are designed to correct the lifted vehicle’s geometry and return your vehicle as closely to stock as possible. They are also fitted with upgraded high-angle ball joints, ICON Delta Joints, which not only improve for performance, but also durability, reliability, and serviceability. Without my ICON UCAs, my GX 460 would wander all over the road, and since I opted for the Delta joint, I’ll gain some of that precious down-travel back as well.

Along with correcting the geometry at the front of the vehicle, I also recognized it was important to take care of the rear geometry, as well. Icon’s rear tubular upper and lower control arms aren’t just stronger; they’re adjustable, which allows me to correct the pinion angle for my rear driveline, reducing vibrations that wouldn’t just drive me nuts but also contribute to premature failure of my U-joints.

ICON Vehicle Dynamics Suspension

The black magic that is high-end off-road suspension is confusing, but if you just break it down it isn’t that bad. Leave the details up to the pros but remember these three main concepts: ensure your vehicle’s weight is properly sprung, give your vehicle enough dampening for how you drive, and when you lift your vehicle always be sure to also correct your vehicle’s suspension geometry. These core concepts will ensure you get your vehicle suspension properly set up for your specific adventure and vehicle requirements.

 

Editor’s Note: A version of this article first appeared in the January/February 2020 print issue of Tread Magazine

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