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King Shock Valving

Shock Valving

Shock absorbers dampen suspension forces by pushing a piston through a specially formulated shock oil. Shims, attached to each side of the piston head, control the stiffness of the shock and determine how much it will dampen the applied forces. Valving shims are found on both sides of the shock piston because a shock absorber works in both the upward (compression) and downward (rebound) directions.

Compression valving controls how a shock absorber reacts to upward forces encountered when a vehicle's suspension is compressed during a bump or landing. All of the forces that go into compressing the suspension system will then immediately be returned back to the wheels by the springs expanding back to their natural position. The rebound valving of a shock absorber is what controls these returning forces and prevents the vehicle from bouncing back up into the air like a basketball.

Shock valving is the key to every high performance suspension system and finding the right shims to use in your shock absorbers requires the consideration of many variables. The following table is a list of items required by Filthy Motorsports as part of any King Shocks purchase to ensure that all shocks are valved precisely to the customer's needs.

King Shock Tuning

For detailed information on how to select the right shims and tune your King shocks
check out CRAWLpedia's Shock Valving Guide and Shock Tuning Guide

New! Check out the Filthy Motorsports King Shock Rebuild Manual

Variable Effect On Shock Valving
Spring Rates The spring rate effecting the wheel on which the shock absorber is mounted will determine (along with the vehicle's weight) the amount of forces being applied to the shock absorber. A stiffer spring will absorb more of the forces during impact, allowing for softer compression valving, but those additional forces will be released during rebound requiring increased rebound valving.
Vehicle Weight Heavier vehicles will require stronger springs that will, in general, require stiffer shock valving.
Front to Rear Weight Ratio While many consider a 50/50 front-to-rear weight ratio to be the goal, the location of your vehicle's engine will likely make it heavier on one end. This difference in weight may require unequal spring rates that will need matching shock valving. For desert racing vehicles that jump on a regular basis, this weight ratio is much more important as it effects how level the vehicle will fly.
Suspension System Design Suspension system type, design, and geometry all have an impact on the forces applied to a shock absorber. While shock absorbers move in a linear fashion, most suspension systems, particularly A-arms, move in an arc that needs to be considered. For vehicles with A-arm or trailing arm suspensions where the shock absorber is mounted near the center of the arm, the forces on the shock will be increased by the effects of the lever.
Suspension Travel While all shocks have one set of valves that act the same throughout the entire shock travel, bypass shocks have adjustable, external passages that allow for multiple zone tuning. With bypass shocks, the more suspension travel and the more bypass tubes your shocks have, the more options you have in tuning them.
Type of Vehicle A lightweight rock crawler, a high speed desert racer, and a lifted daily-driven pickup truck all have very different purposes and driving conditions. While all three could run the exact same model of King shocks, they will need vastly different shock valving to ensure the best performance out of each type of vehicle.
Desired Ride Height The ride height of the vehicle, in combination with the size and location of the shock absorber, will determine how much up-travel and downt-ravel the suspension system has. Knowing where the piston sits in the shock body at normal ride height is necessary to selecting the appropriate shock valving.
Expected Vehicle Speed As vehicle speed increases, so does the impact force of any given bump. For this reason, a vehicle used for high speed desert racing will need significantly stiffer shock valving than if it were used for rock crawling.

Selecting the proper shock valving is as much of an art form as it is a science. Even with all of the information listed in the above table, selecting the initial valving for a set of shocks is still just an educated guess. The experts at Filthy Motorsports and King Racing have the knowledge and experience to get your shocks valved very close to your exact needs the first time, it is important to know that the only way to fine-tune your suspension is through trial and error.

By design, all King shocks are very easy to service, revalve, and tune. All it takes is a few basic hand tools, the appropriate parts, and about an hour of time. Shim stacks and all other King shock parts you need to custom tune your shocks are available through Filthy Motorsports. If, however, you prefer not to revalve your shocks yourself, you can always send them to Filthy Motorsports and they will service them for you.