Redcat Suspension Tuning: Springs, Shocks and Ride Height

Quick answer

Tune in this order: set ride height first, then match shock oil weight to your surface, then adjust damping with pistons or oil, and only then change springs. Change one thing at a time and test on the same surface. Most handling problems come from a suspension that is too stiff or ride height that is too high, not from a lack of parts.

Set ride height before anything else

Ride height is the distance between the chassis bottom and the ground at rest. On a Redcat truck or crawler, aim for the suspension arms to sit slightly above level, with the driveshafts roughly horizontal. If you raise ride height too far, the truck tips easily and shocks top out; too low and the chassis slaps the ground on landings. Adjust by turning the shock preload collars or moving the clip position on the shock body. Measure at the center of the chassis, not at the bumper, and recheck after every change.

Match shock oil weight to your surface

Shock oil weight controls how fast the suspension moves. Thicker oil slows the motion, which suits high-grip surfaces and big jumps; thinner oil lets the suspension react faster on loose or bumpy ground. For general bashing, a middle weight is a safe start. For crawling, thinner oil helps the tires stay planted on slow, technical lines. If you change oil weight, do all four shocks at the same time and keep the same volume so the damping stays balanced.

Adjust damping with pistons and oil, not springs

Damping is the shock's resistance to movement, and it is separate from spring rate. If the truck bounces after a landing, the damping is too light for the spring; if it feels harsh and skips over bumps, the damping is too heavy. Use piston holes or oil weight to change damping. Do not try to fix a bouncing truck by installing stiffer springs, because that usually makes it bounce more. Test by dropping the truck from about knee height and watching how it settles.

Choose springs last and keep them matched

Springs hold the truck up and set how much it leans in corners. Change springs only after ride height, oil, and damping are close. Softer springs help on loose dirt and rock; stiffer springs reduce body roll on high-grip tracks. Keep front and rear springs within one step of each other unless you are tuning for a specific track. If a spring is too stiff, the truck will not use its full suspension travel, and you will lose grip.

Check wear parts before you tune

A worn or leaking shock will make every tuning change feel wrong. Before you adjust anything, look for oil residue on the shock body and check that the shaft moves smoothly. Replace damaged seals and bent or worn hinge pins, because slop in the suspension arms adds unpredictable steering and camber changes. On a Redcat Machete, the RER19372 shock O-rings are a four-piece replacement seal set that restores proper shock function and matches original specifications. On a Rampage MT or Rampage Dunerunner, part 50235 is a two-piece set of 6x61mm rear lower outer hinge pins; worn pins let the rear arms move around and ruin your ride height settings. If you run a Vigilante, the RER26311 lower skid plate (center) shields the chassis underside from rocks and debris, which protects the suspension mounts you are tuning.

Suspension tuning steps

1. Step 1: Set ride height: Turn the preload collars or move clips so the chassis sits slightly above level with driveshafts roughly horizontal. Measure at the chassis center. Common mistake: setting ride height by eye at the bumper instead of the center, which gives an uneven reading.
2. Step 2: Pick shock oil weight: Use thicker oil for high-grip surfaces and jumps, thinner oil for loose or bumpy ground. Change all four shocks together and keep the volume equal. Checkpoint: after a run, the shocks should be warm but not hot; if they are hot, the oil is too thin for the conditions.
3. Step 3: Adjust damping: If the truck bounces after a landing, reduce damping with lighter oil or larger piston holes. If it skips and feels harsh, increase damping. Do not fix bounce with stiffer springs. Common mistake: changing springs to fix a damping problem, which usually makes the bounce worse.
4. Step 4: Change springs last: Go softer for loose dirt and rock, stiffer for high-grip tracks. Keep front and rear within one step of each other unless tuning for a specific track. Checkpoint: the truck should use most of its suspension travel without bottoming out on normal landings.
5. Step 5: Inspect wear parts: Look for leaking shocks, smooth shaft movement, and play in the hinge pins. Replace worn seals and pins before you chase handling with more tuning. Next step: test on the same surface and change only one setting at a time so you know what worked.

Parts that support a proper suspension tune

• RER19372: RER19372 is a set of four shock O-rings designed for the Machete, engineered to OEM dimensions and performance. Fresh seals stop oil weeping and keep damping consistent, so your oil weight and ride height changes actually hold.
• 50235: 50235 is a two-piece set of 6x61mm rear lower outer hinge pins listed for the Rampage MT and legacy Rampage Dunerunner. Tight hinge pins remove rear-arm slop that otherwise makes ride height and camber settings drift.
• RER26311: RER26311 is a single-piece center lower skid plate for the Vigilante, built to shield the lower chassis from rocks and debris. Protecting the chassis underside reduces impact damage to the suspension mounts you are tuning.