G2-R FORK COMPRESSION | |||||||
G2-R THEORY There are many ways to setup the valving with G2-Rs. They are made to be preloaded (digressive) or restricted (extremely progressive). This adds a little complexity but makes them extremely versatile. PRELOAD to FREELOAD For Gold Valves 28mm and smaller the piston face has a 0.5mm Step on it (30mm and larger have a 1.0mm Step). This means if you put on a valving stack directly on the piston (without a Restrictor Stack) the shims would become pre-bent 0.5mm when the nut is tightened. This is a 0.5mm preloaded stack (which is WAY too much for any real world application). The Restrictor Valving Stack thickness, in relationship to the depth of the Step, sets this preload. The best preloads are typically between zero and 0.10mm. Zero preload is the most common. Preload = Step – (Restrictor Stack Height) example: 0.50mm – 0.40 = 0.10 preload | |||||||
G2-R Theory continued PORT SIZE The Restrictor Valving serves a second function. Increasing the diameter restricts the flow area of the ports. This increases the damping at high velocities like landing off a jump. CAUTION The problem is production tolerances. Everything that is made has a production tolerance. This includes every shim as well as the depth of the Step. These can all add up to much different preload than predicted. To get it right you must measure the Total Restrictor Stack Thickness as well as the depth of the Step to calculate the Preload. | |||||||
LSV (LOW SPEED VALVE) These instructions cover installation with/or without a Low Speed Valve (LSV). LSV Compression Holders are identified by a second valving stack below the Compression Base Plate. The LSV Stack is fed by the Compression Adjuster. Stiffer LSV Valving makes the front end ride higher. | |||||||
Welcome to the wonderful world of Gold Valving. To obtain your personal Custom Suspension Settings: 1.Go to Digital Valving Search (DVS) For general fork rebuild procedure refer to the Fork Gold Valve Instruction List. CAUTION: IF YOU ARE UNFAMILIAR WITH REBUILDING AND REVALVING FORKS, STOP!!! DO NOT PROCEED; SEEK OUT A QUALIFIED SUSPENSION TECHNICIAN. NOTE: All measurements are metric (for inches divide by 25.4). The valving list starts at the piston face and goes towards the Base Plate. Valve specs are listed by (QUANTITY) THICKNESS x DIAMETER. A number in parentheses means quantity. If there is no number in parenthesis the quantity is one. Example: (2).15x30 means quantity two, 15 hundredths of a millimeter thick by 30 millimeters in diameter. | |||||||
Tools Required - In-lb torque wrench that accurately measures 0 to 50 in-lbs (0.58 kgf-m) (SnapOn Digital Torque Wrench shown) - Hi-Strength Loctite (included) - Metric calipers and micrometer | |||||||
There are about four styles of compression holders with a few subtle hardware differences but are all very similar. Non-LSV Type Compression Holders are the same but without the LSV Stack. | |||||||
VP1- Most Japanese forks like KYB and Showa have peening on the end of the shaft for nut retention insurance. File the peening from the top of the compression shaft down to the top of the nut. There are some models where the shaft is "staked". This means there are sharp notches instead of smooth peening. In this case be sure the notches are completely cleaned out. Euro models like WP, Sachs, and Ohlins are not peened and don't require this step. | |||||||
VP2- The shaft should be ground to the nut's surface. Once this is done, remove the nut and Valving Stack. | |||||||
VP3- On peened type holders, slightly chamfer the end of the thread with a fine file. Do not be too aggressive as on some models there is not much thread. If you blow it and mess up the thread please call us as we may have a solution available. Dressing the end with a wire wheel makes it very clean. | |||||||
VP4- Blow air through one of the side holes while covering up the other side hole. This blows out fillings. Use contact cleaner and repeat. | |||||||
VP5- LSV - Install the LSV Stack and the Base Plate(s) on the Shaft.Non-LSV - Install the Base Plate(s). Note the largest diameter shim goes on the shaft first. There are models that require 2 or even 3 Base Plates to create the correct Total Valve Stack Height. See step VP11. There are some valving stacks that do not completely cover the seat intentionally. This disables the LSV and converts it to a conventional adjustable bleed. See your DVS Setup Sheet and the image below. | |||||||
VALVING STACK TYPES - SINGLE OR TWO STAGE VP6- You will either be building a Single Stage or a Two Stage Stack. The difference is the Crossover. The Crossover is a smaller diameter shim between the Lo-Speed and the Hi-Speed Stacks. Note: The DVS Custom Setup Sheet displays individual shims and does not label Hi-Speed, Crossover, and Lo-Speed. This is for your information only. Also you will not use all the shims provided in the Gold Valve Kit.
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VP7- Two Stage Example (Single Stage is exactly the same except there is no Crossover) Put the valving on the shaft in the reverse of the order listed, starting with the last (smallest) shim of the Hi-Speed Stack. For Two Stage the total valving stack is made up of a: Restrictor Stack Lo-Speed Stack Crossover and a Hi-Speed Stack (this is only an example for a 28mm piston to show the direction of the taper - not your setting) The Total Valving Stack starting from the Gold Valve piston face: (2) .15x17 - Restrictor Stack (.50 thick for 0 preload) (2) .10x12 - part of the Restrictor Stack (4) .15x24 - Lo-Speed Stack (1) .10x16 - Crossover (notice the smaller diameter) (1) .10x24 - Hi-Speed Stack (1) .10x22 (1) .10x20 (1) .10x18 (1) .10x16 (1) .10x15 (1) .10x14 (1) .10x13 (1) .10x12 | |||||||
Measure the total Restrictor Stack Thickness (1.009mm) | VP7a- SETTING VALVE STACK PRELOAD - CRITICAL!!! The tricky part of setting up a G2-R is controlling the Valve Stack Preload. Remember I said this is the "Tuner's Valve". This is the part where spending a bit of extra effort pays off. As mentioned before, production tolerances, both with shim thickness and depth of the Step, can cause problems. Measure the Total Restrictor Stack Thickness (not just the calculated one) by stacking all the Restrictor shims together and measuring them as a unit. Measure the depth of the Step as shown and calculate Preload. Preload = Step – (Restrictor Stack Height) In this example: 1.038 - 1.009 = .029 preload | ||||||
VP7b- SETTING VALVE STACK PRELOAD - Method 2 Another method is to first stack up the Restrictor Stack in the Step on the piston. Then put a parallel or straight edge across the piston and measure the preload with a feeler gauge. If the DVS calls for no preload it is easier to remove 1 shim and measure the clearance starting with a feeler gauge the same thickness as the removed shim. Change feeler gauges until it fits snugly. Add the removed shim's thickness back into the calculation. | |||||||
VP7c- SETTING VALVE STACK PRELOAD - What to do if actual preload is different than the desired preload. If it is off by .05mm swap out a .10 shim for a .15 or vice versa. If it is off by .02 - .03 sometimes you can find shims that are slightly different thickness in the stock stack. As long as the replacement shim is equal or smaller in diameter it is ok. You can also sand the Step down a little with 400 grit sandpaper on a piece of glass or surface plate. Be careful as a little sanding can remove material quicker than you think. If you go crazy and destroy the piston well... Also note that 99% of all digital calipers are out of adjustment and will give you false readings. Micrometers are far better at accurate measurements. | |||||||
VP8- COMPRESSION BLEED HOLE If the DVS does not call for a Compression Bleed Hole skip this step. If your DVS Setup Sheet calls for a Compression Bleed Hole check to see if it is already pre-drilled in the piston. If it is not you will need to drill one. Notice that the bleed hole is on the side of the piston with the recess and is drilled sideways. It connects the two sides of the piston and bypasses the valving stack. The exact location is not critical. | |||||||
VP10a- Place the Check Plate, Check Spring, and either: 1- Sleeve, Cupped Washer, and Nut | |||||||
VP10b- or 2- Sleeve Washer and Nut (This type could also use a Wave Washer instead of a coil spring.) | |||||||
VP10c- or 3- Check Nut on the Shaft. | |||||||
Incorrect stack height is shown in this photo (this stack is too short). This is correct. | This step is here to insure you don't "run out of thread" when tightening the Nut and the Nut gets full engagement. The shims should be guided with the straight, non-threaded part of the shaft and should not be on the thread so the thread should be covered by the Base Plate. This height adjustment is done with Spacing Shims. If needed, they should be added just above the Base Plate. Spacing Shims must be larger in diameter than the smallest shim in the stack. Click on the image to enlarge. | ||||||
VP12- Apply a small drop of Loctite to the valving shaft nut. | |||||||
VP13- Check to make sure the check valve is free before the nut is tightened. | |||||||
VP14- tighten it to spec with a torque wrench. CAUTION! The threads can be damaged without extreme care. You must use Loctite. Torque the Nut to the spec on your DVS Setup Sheet. NO MORE! Do not take this step lightly.This is critical! | |||||||
VP15- Single Stage | |||||||
VP16- Make sure the Check Plate is free and can move up and down against the Spring. | |||||||
VP17- Visually check your work. Hold the Valving Stack up to the light and look for proper assembly. If there are any problems, disassemble the stack and look for burrs to surface and/or dirt in the valving. Reassemble and check again. On two-stage stacks make sure the Crossover Gap is clearly visible. Make sure the o-ring is on the Gold Valve. Some kits contain more than one o-ring. See your DVS Setup Sheet Valving Comments for the correct o-ring. | |||||||
VP18- Make sure the shims that go next to the Gold Valve completely cover the ports on both sides of the piston! If the ports are not covered there will not be enough damping. This could be caused by a number of reasons. Please call Tech Support if this occurs and you can't figure it out. | |||||||
VP19- Return to the main instructions and continue with Rebound Valving and Assembly. |
• Single Stage - made of: Lo-Speed Stack Hi-Speed StackThere is NO Crossover (it becomes one stack.) | ||
• Two Stage - made of: Lo-Speed Stack Crossover Hi-Speed StackThe Crossover Gap is visible |