In the world of go-fast desert racing, bypass shocks are required equipment. Not because they look and sound cool, but because they offer precision control over compression and rebound damping. Simply put, bypass shocks allow you to go fast in the dirt. They do this by giving you the ability to fine-tune the velocity at which the suspension system reacts to the terrain in specific "zones" of wheel travel. King Off-Road Racing Shocks has been building racing shocks for over 14 years now. As such, King has perfected many of the variables that other manufacturers struggle with in terms of material selection and manufacturing ability. With this story, we will showcase how race-grade bypass shocks are built, and also show how they're tested-in this case, on an Ultra 4 desert racecar in Johnson Valley, California. We recently toured King's Southern California shock-manufacturing facility. Read on to see what we learned about the way race-caliber bypass shocks are made. On-Site Tuning Services When a racer makes the decision to run King shocks, the product comes out of the box ready to run. Off Road Design opted to exercise King's on-site tuning services to test a set of King triple-bypass race shocks in preparation for The Best in the Desert (BITD) racing series. With this service, King sends out one of their in-house tuning specialists to help dial in the shock tuning to the specific racecar and/or terrain. The technician might make a few simple adjustments to the bypass tubes, or he may swap out coil springs to dial in a better spring rate. In some cases, the technician might even take the shock apart on location and re-valve it for better performance. We tagged along during Off Road Design's tuning session at Johnson Valley and documented the process. Here you can see Iribe making adjustments to the bypass tubes. Within a few minutes, he had ORD's Ultra 4 car running smooth and fast over some of the roughest whoops sections we could find. Here, King's lead shock tuning specialist Gerardo Iribe explains how the shaft assembly is fitted to the body of a King bypass shock. Iribe has a long history in desert racing and chassis-specific shock tuning. From Baja to Dakar, high-profile teams in multiple racing disciplines regard Iribe's work as among the best in the business.Here, King's lead shock tuning specialist Gerardo Iribe explains how the shaft assembly is This is where all King shocks begin life. The raw material that King uses is precision-drawn DOM tubing that is manufactured to very specific tolerances. This material comes pre-honed and is sourced from a U.S. supplier.This is where all King shocks begin life. The raw material that King uses is precision-dra Next, the DOM tubing is loaded into a CNC cutting machine that divides the tubing into specific-length pieces. These pieces will eventually become shock bodies.Next, the DOM tubing is loaded into a CNC cutting machine that divides the tubing into spe Once the DOM tubing is cut to length, each tube is wrapped with a protective layer of paper. Each batch is then organized and stored near the assembly area for easy access.Once the DOM tubing is cut to length, each tube is wrapped with a protective layer of pape This shot shows King's shock assembly department. Every shock King produces undergoes a stringent array of quality-control inspections during the assembly process.This shot shows King's shock assembly department. Every shock King produces undergoes a st Similar to the blueprints of a home, every bypass shock requires a predetermined map prior to assembly. Each configuration requires a specific arrangement of tubes. King maps out each shock body plan with ink on the exterior of the body prior to assembly. This photo shows a typical bypass layout after it's drawn. From there, a center-punch tool is used to create drill index marks.Similar to the blueprints of a home, every bypass shock requires a predetermined map prior This is the bulkhead adapter that ties the entry side of the bypass tube to the shock body. Each bypass tube requires one of these units.This is the bulkhead adapter that ties the entry side of the bypass tube to the shock body After a series of holes was drilled into the shock body, a technician de-burred each unit by hand and then double-checked each unit against a set of plans.After a series of holes was drilled into the shock body, a technician de-burred each unit Next, a highly-skilled TIG welder installs each of the bypass tubes as per the instructions of the layout.Next, a highly-skilled TIG welder installs each of the bypass tubes as per the instruction Here, you can see what the bypass tubes look like after being TIG-welded to the shock body.Here, you can see what the bypass tubes look like after being TIG-welded to the shock body Once each bypass tube is attached to the shock body, the assembly is sent out for cadmium plating, re-honing, and micro-polishing. A day or two later, the parts are returned to King's facility, where each unit receives a thorough inspection. Occasionally, King will reject a batch if specific tolerances are not met.Once each bypass tube is attached to the shock body, the assembly is sent out for cadmium With the shock body completed, the cylinder assembly process can begin. Here, you can see all of the additional components that are required.With the shock body completed, the cylinder assembly process can begin. Here, you can see First, each bypass tube is fitted with an arrangement of parts that make up the internals of the bypass valve and adjustment mechanism.First, each bypass tube is fitted with an arrangement of parts that make up the internals The assembly process begins with the shaft assembly. The Performance Race shafts are made from 1050 steel that are hard-chromed and micro-polished. King's Pure Race shafts are induction-hardened, hard-chromed, and polished to a mirror finish. Once the shaft finish is applied, King installs a billet aluminum rod end. This part is threaded to the shock shaft with a special thread locking compound.The assembly process begins with the shaft assembly. The Performance Race shafts are made This part is called the seal head. This is what keeps the shock oil contained inside the shock housing.This part is called the seal head. This is what keeps the shock oil contained inside the s With the seal head installed on the shock shaft, Iribe stacked each of the corresponding parts in the specific order shown here.With the seal head installed on the shock shaft, Iribe stacked each of the corresponding p This is a two-sided shock valve piston. One side is for compression, the other for rebound. The side shown is for compression. Notice the way that six of the holes on this particular side of the piston feature porting, which allows the shock oil to pass around the rebound shims or valve stack in a uniform fashion. This particular piston design allows the piston to flow twice as much oil in the compression direction as it could on the rebound side. Here is how it works: As the shock shaft compresses, the oil flows through the six ported holes on the visible side of the piston. When the shock shaft extends, the oil flows back through the three holes on the visible side of the piston. Pistons can be configured in several different ways, depending on the intended use of the shock. The smaller bleed hole allows a small portion of oil to flow through the piston without restriction. Sometimes a piston can have multiple bleed holes. Typically, bleed holes soften the effect of the valving.This is a two-sided shock valve piston. One side is for compression, the other for rebound This particular piston features a groove for an O-ring to be installed under the wear band-an exclusive feature you will not find on other shocks. This particular arrangement is reserved for King's high-performance Pure Race shock line. In addition to providing a better seal at the split in the wear band, the O-ring also helps maintain consistent pressure between the wear band and the inner bore of the shock body. This ensures that shock oil cannot leak past the wear band, which optimizes the valving function.This particular piston features a groove for an O-ring to be installed under the wear band Here, you can see how the wear band fits snugly over the O-ring of the piston. This is how the different components of the shock valve look on the rebound side of the shock shaft. All King pistons feature like-size holes on the compression and rebound sides of the piston. A shock-specific valve profile comes from port size and shim configuration. A base washer separates the rebound valving from the nut that secures the assembly to the shock shaft. The specific thickness of the base washer relates to how much space the wafers need to deflect as the shaft assembly strokes.This is how the different components of the shock valve look on the rebound side of the sh King takes pride in the way their end cap seals against the body of the shock. Notice how the O-ring is located well below the threaded area of the billet aluminum end cap. This arrangement ensures that the seal can withstand the high internal pressures common to racing shocks. This configuration helps prevent leaks when the shock temperatures spike. The threads of each end cap are specifically timed to its matching shock body so the bypass tubes have the necessary clearance when installed on the vehicle. Numbers on each part ensure that the correct parts are used together.King takes pride in the way their end cap seals against the body of the shock. Notice how This is the custom tool King uses to assemble the end cap to the shock cylinder. The small peg visible in the photo extends outwards into a hole for the remote reservoir. The peg locks the tool in place. Next, the end cap is clamped into a vise.This is the custom tool King uses to assemble the end cap to the shock cylinder. The small With the top cap secured in a vise, the body was attached using a special tool that grabs two holes on the inner bore of the body. A large adjustable wrench was used to tighten the assembly.With the top cap secured in a vise, the body was attached using a special tool that grabs With the end cap secured to the cylinder, the next step involves filling the cylinder with shock oil. King uses a special oil that is formulated to withstand high temperatures.With the end cap secured to the cylinder, the next step involves filling the cylinder with Here, Iribe installs the shaft assembly into the shock cylinder. Notice how he squeezes the wear band to release pressure.Here, Iribe installs the shaft assembly into the shock cylinder. Notice how he squeezes th This shot shows the level of the shock oil when the unit is full. A spanner wrench was used to tighten the seal cap to the shock cylinder. The remote reservoir features the same honed finish on the inner bore. A divider piston was added to the remote reservoir cylinder. This unit separates the shock oil from the nitrogen gas. Once filled with nitrogen, the gas chamber applies pressure to the oil chamber in the shock. This eliminates the foaming effect that can occur when air bubbles mix with the shock fluid.A divider piston was added to the remote reservoir cylinder. This unit separates the shock With the divider piston installed, Iribe adds a small amount of oil to lubricate the piston's O-ring on the nitrogen side.With the divider piston installed, Iribe adds a small amount of oil to lubricate the pisto After the divider piston is in place inside the remote reservoir, Iribe adds an end cap that features a valve stem for charging the reservoir with nitrogen. Additionally, stickers are installed to complete the job.After the divider piston is in place inside the remote reservoir, Iribe adds an end cap th At the 2009 Best in The Desert Vegas to Reno race, Off Road Design ran hard and fast, thanks to King's awesome 2.5-inch triple bypass shocks.At the 2009 Best in The Desert Vegas to Reno race, Off Road Design ran hard and fast, than SOURCES Offroad Design 484 County Road 113 Carbondale CO 81623 970-945-7777 http://www.offroaddesign.com/ King Shocks 12842 Joy Street Garden Grove CA 92840 714-530-8701 www.kingshocks.com By Robin Stover Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!
mattiacono 4/6/2011 at 3:38 AM Great detail it really makes it obvious why these are so much better then the competition. Also shows the care and pride takes in their work.
MNorby 3/29/2011 at 2:51 AM Great article and awesome close up pictures of the internals piece by piece. Even better on the Watson's race buggy.
