Trophy trucks are the pinnacle of off-road racing, known for their massive suspension travel and ability to absorb brutal terrain at high speeds. At the heart of these machines is a sophisticated suspension system engineered to maintain traction and control. Whether you're building a trophy truck from scratch or upgrading an existing rig, understanding the key suspension parts is essential. This guide covers the critical components, their functions, materials, and factors to consider when selecting parts.
Shop on Amazon
Browse the latest options and prices.
HPI Racing Suspension Holders Trophy 101100
Shocks and Bypass Systems
Coilover Shocks
Coilover shocks are the primary dampers in a trophy truck suspension. They combine a coil spring and a shock absorber into a single unit. High-end coilovers use progressive or dual-rate springs to handle varying loads. Typical travel ranges from 16 to 24 inches per wheel. Look for shocks with large-diameter bodies (2.5 to 4 inches) and chrome-moly shafts for durability. Brands like Fox, King, and Walker Evans Racing are common in this segment.
Bypass Shocks
Bypass shocks are specialized dampers with external tubes that allow tuning of compression and rebound at different points in the travel. They provide progressive damping without the harshness of fixed-valve shocks. A typical trophy truck might have 4-8 bypass tubes per wheel. These shocks are rebuildable and can be adjusted for different terrain. They are critical for controlling the chassis during high-speed whoops and g-outs.
Air Shocks
Some trophy trucks use air shocks, which use compressed nitrogen as the spring medium. They are lighter than coilovers and offer easy preload adjustment by changing air pressure. However, they can suffer from heat buildup and inconsistent performance in long races. They are less common than coilovers but used in some desert race trucks.
Springs and Hardware
Coil Springs
Springs in trophy truck suspension are typically made from chrome-silicon or chrome-vanadium steel for durability and sag resistance. Dual-rate springs are popular, using a soft spring for small bumps and a stiff spring for big hits. Spring rates are measured in pounds per inch (lb/in) and should be selected based on vehicle weight and intended use. Progressive springs are also used to provide a softer initial ride.
Spring Accessories
Adjustable spring seats, threaded collars, and preload spacers allow fine-tuning of ride height and spring preload. Tender springs are sometimes added to keep the main spring in place during droop travel. High-quality spring retainers and isolators reduce noise and wear.
Control Arms and Links
Upper and Lower Control Arms
Trophy truck control arms are typically fabricated from chromoly or DOM steel tubing in a triangulated design to handle high loads. They use rod ends (heim joints) or spherical bearings at the chassis and hub connections. Bushings should be high-misalignment to allow large articulation. Some arms use forged aluminum for weight savings, but steel is more durable for heavy impact.
Trailing Arms and Links
Rear suspension often uses a four-link or three-link setup with trailing arms. These arms locate the axle laterally and longitudinally. Typical materials are 1.5- to 2-inch-diameter chromoly tubing with 4130 mild steel. Link lengths and angles affect anti-squat and roll center, so careful geometry is required. Adjustable links allow fine-tuning.
Steering and Knuckles
Spindles and Knuckles
Trophy truck knuckles are massive, often machined from billet aluminum or cast high-strength steel. They house the wheel bearings and attach to the control arms. Uniball (spherical bearing) connections are standard for zero binding. The steering arm is integrated, and Ackerman geometry is optimized for tight turns in desert conditions.
Steering Racks and Tie Rods
Rack-and-pinion steering is common in trophy trucks for its precision and compactness. Racks are often relocated behind the front axle for protection. Tie rods are heavy-duty, using 1.25-inch-diameter chromoly tubing with high-misalignment rod ends. Hydraulic steering assist is sometimes added for heavy loads.
Sway Bars and Limit Straps
Sway Bars
Some trophy trucks use sway bars to reduce body roll, but they are not universal because they limit independent articulation. When used, they are typically splined or blade-style bars with adjustable links. Some drivers prefer no sway bar for maximum wheel travel.
Limit Straps
Limit straps prevent the suspension from over-extending and damaging shocks or CV joints. They are usually made of nylon webbing with steel ends. Length must be selected to match maximum droop. They are simple but critical safety items.
Bushings and Bearings
Spherical Bearings and Rod Ends
Nearly all pivot points in a trophy truck suspension use spherical bearings (heiam joints or uniballs) to allow free rotation in multiple axes. They are made from heat-treated steel or stainless steel with PTFE liners for low friction. Common sizes range from 3/4 to 1 inch for rod ends and up to 2.5 inches for uniball cups.
Wheel Bearings
Wheel bearings are full-floating tapered roller bearings or unitized hub assemblies. They must handle axial and radial loads. Grease maintenance is frequent due to dust and water ingress.
Materials and Construction
Steel vs. Aluminum
Chromoly 4130 steel is the standard for most suspension parts due to its high strength-to-weight ratio and weldability. 4041 or 4130 are common. Aluminum (6061-T6 or 7075-T6) is used in billet components like knuckles and sway bar arms where weight savings matter. Carbon fiber is rare due to cost and impact fragility.
Welding and Fabrication
All welds should be TIG or MIG with proper penetration. Heat treating after welding is often recommended for high-stress parts. Jigging is critical to maintain geometry.
Practical Buying and Setup Tips
- Start with a clear budget and performance goal. Buying the most expensive shocks won't help if your control arm geometry is off.
- Choose a reputable brand with local service availability. Fox, King, and Sway-A-Way offer rebuildable shocks with good support.
- Match spring rates to your vehicle's weight and intended use. Softer for rock crawling, stiffer for high-speed desert.
- Inspect all parts regularly for cracks, wear, and loose fasteners. Trophy trucks see extreme loads.
- Consider a full suspension kit from one manufacturer for coordinated valving and geometry.
- Don't overlook small parts like limit straps and bump stops. They prevent costly damage.
- Work with an experienced shop or builder if you lack suspension design knowledge.
Final Recommendation
Building a trophy truck suspension is as much about engineering as it is about parts selection. Focus on a well-designed shock package (coilover and bypass) from a proven manufacturer, paired with chromoly control arms and high-quality spherical bearings. Spring rates should be chosen after weighing the truck and simulating loads. Invest in adjustable components to allow tuning for different race courses. Remember that the suspension is the most important system for speed and control—don't skimp on quality or setup time.