FORK GOLD VALVE CARTRIDGE EMULATOR INSTALLATION | |
TFDH 01 Damping Rod Holding Tool | 1 - TOOLS AND SUPPLIES
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Round 6 Point 12 Point | 2 - STANDARD CUPPED-TOP DAMPING ROD - This is the most common type of damping rod on Japanese KYB and Showa forks from the early 70s to present. The top of this damping rod is cupped. The inside of the head may be round (top), 6 point hex (middle) or 12 point (bottom). The hex is for an OEM holding tool. Piston rings are standard on modern damping rods. If there is no stock piston ring the Emulator Adapter will have one built in. Emulators are designed to sit in the cup on top of these damping rods. The fit does not have to be exact. The requirement is that the Emulator must cover the top opening completely. Move it over to the side to check for gaps. The main fork spring holds the Emulator in place. |
Flat-Top Suzuki DR350
Protruding-Top, Wimpy Piston Ring 1974 KX250 | 2A - NON-CUPPED AND NON-STANDARD DAMPING RODS - These come in two basic styles; Flat-Top and Protruding-Top. More Details... EMULATOR ADAPTERS
OTHER
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3 - Remove the damping rods. Take the forks off the bike and disassemble them. An impact and a long Allen socket helps a lot. For stubborn Damping Rod Allen bolts use a drift and beat on the head of the damping rod bolt to jar the threads loose. Most forks can be disassembled without a holding tool by leaving the spring in and compressing the fork to provide resistance to turning while using an impact. For really stubborn bolts use a TFDH 01 Damping Rod Holding Tool. TFDH 01 – Unless you are doing a complete overhaul you may not have to remove the seals. Simply take the fork spring and the damping rod bolt out, turn the fork upside down and the damping rod will fall out. The only tricky part is making sure the bottoming cone gets installed correctly. | |
Pushed Sideways - Gaps Open Sizing Circlip Off Sizing Clip Installed Pushed Sideways - Still Covered | 4 - Check the fit of the Emulator by placing it on top of the damping rod. The step on the Emulator must sit into the top of the damping rod. The Emulator must completely cover the hole in the top. If your application calls for an Emulator Adapter it goes onto the Damping Rod first. The Adapter may be directional (there is an up side and a down side). Some Emulators (FEGV 4301 and 4101) come with Sizing Circlips (pictured). This allows proper fit for more than one ID damping rod. Check to determine if you need the Sizing Circlips by installing the Circlip and checking if it will fit into the top of the damping rod. The Circlip is for location only. |
5 - Check the Fork Spring to Valve Plate clearance. The inner diameter of the fork spring must be at least 4mm (0.160”) larger than the Emulator Valve Plate itself for proper flow. This may be a problem if you are not using a RT Spring. NOTE: The spring rests directly on the Emulator. There is no washer under the spring. | |
Top Compression Holes Stock - Bottom Modified | 6 - Enlarge the Compression Feed Holes Based on Damping Rod Diameter:
Enlarge existing compression holes and add holes if necessary so you end up with six holes (3 sets of 2 holes). New holes should be spaced lengthwise above the existing holes at 10 mm (7/16") increments. Place each set of two holes 90 degrees from the last set so the strength of the rod is maintained. There are exceptions to this as some models keep the holes in the same line. See notes on the DVS Setup Sheet. After drilling, chamfer and deburr the compression holes, inside and out. The exact size of the holes is not critical. There needs to be enough flow area. This step transfers control of the damping from the compression holes to the Emulator. Anti-Dive - Models with Anti-Dive are particularly sensitive to correct hole location. On rods with bottoming cones the additional compresson feed holes should start just above the cone. See "Special Valving Instructions for this Kit" in Product Search or the Anti-Dive section of the Damping Rod Gallery. |
Rebound Hole | 7 - Rebound Holes - Unless directed, do not add or enlarge the rebound holes (near the top of the damping rod) and leave their edges sharp. Adjustable Rebound models that require brazing may need work in this area. See "Special Valving Instructions for this Kit" in Product Search. |
Linear Valve Stock and Disabled | 8 - Stock Valves - If there is any type of compression valve or adjuster, it must be removed or disabled. Variations: Linear Valves - The valve shown at the left is called a Linear Valve. Very common on dirt bikes in the 80s. It is part of the bottom bolt. It is modified by cutting it off where it goes into the bolt. You will no longer have external adjustment, however you won't care so much once you've ridden. More Details... Damping Rod Top Valves - A few models have an existing valve that sits on top of the damping rod. One version is called a TCV found on KYB dirt forks in the mid 1980s. They have a valving rod attached to a spring sitting on top of the damping rod. Remove these stock valves. Anti-Dive - Found exclusively on street bikes, Anti-Dive is disabled and not needed with Emulators. The addition of correctly located Compression Feed Holes takes care of this. More Details... Adjustable Rebound - External adjusters are found on some street bikes. Often these are disabled. More Details... |
Exploded View Emulator Cutaway | 9 - Setup the Emulator Valving Consult your DVS Setup Sheet.
VALVE SPRING RATE Determine which Valve Spring is installed by its color and change it if necessary.
VALVE SPRING PRELOAD
BLEED HOLES
Be sure to tighten the jam nut before use. |
10 - Reassemble the forks according to your manual. Remember to install the top-out spring and bottom-out cone. Consult manufacturers specs for damping rod bolt torque. | |
SETTING FORK SPRING PRELOAD - METHOD #1 | |
11 - Setting the fork spring preload is done by making the correct length preload spacers. Find the recommended preload in Product Search or on your DVS Setup Sheet. 1. If your forks have Preload Adjusters set them to minimum. 2. If you have a fork with an Emulator. Drop the Emulator down the tube. Install the Emulator Adapter first if required. It sits on top of the damping rod with the Emulator Valve Spring facing up and is held in place with the main fork spring. Visually check to make sure the Emulator is sitting squarely on top of the damping rod or the Adapter. 3. Extend the fork tube all the way. 4. Insert the fork springs into the fork tube on top of the Emulator 5. Install a steel fork spring washer 6. Install the fork spring spacer tube. Any length that goes above the top of the fork tube is ok for now. 7. Install another steel fork spring washer 8. Set the fork cap on the washer 9.Measure from the top of the fork tube to the sealing lip on the fork cap. This is a direct measurement of fork spring preload. 10. Adjust the spring spacer tube length to achieve the proper preload. In this example using the image above: If you are looking for 15mm preload you would shorten the spacer by 46 - 15 = 31mm NOTE: You must have steel washers on both ends of the spacer. The spacer must not rest directly on the spring or the cap. | |
SETTING FORK SPRING PRELOAD - METHOD #2 | |
12 - If there is very little preload the thread on the cap will hit the thread in the fork tube before touching the washer. Measure from the top of the fork tube to the Steel Spring Washer. In this case 11mm | |
13 - Measure the Fork Cap Height In this case 18mm. (The fork cap is upside down) Calculate the Preload (Fork Cap Height) - (Top to Washer) = Preload 18 - 11 = 7mm Preload Adjust the Spacer Length or add washers to get the recommended Preload. | |
TFOL 02 | 14 - Install the fork fluid and set the oil level. Use the oil viscosity recommended by the DVS. Make sure: 1. The Fork Spring is out 2. The Emulator is in completely submerged in oil 3. The fork is fully bled by pumping them slowly through their travel 4. The fork is fully bottomed 5. Measure from the top of the fork tube down to the top of the oil Setting the oil level can be done with a tape measure or with a Fork Oil Level Setting Tool TFOL 02. The Oil Level Tool is shown being set to the proper level before use. TFOL 02 – |
15 - Finish reassembly by installing the spring and spacer. Before you install the fork cap, re-check the spring preload. This will indicate whether the Emulator is seated properly. Install the fork caps and, with the forks off the bike, push on them, checking for any unusual drag or bind that would indicate an improperly seated Emulator. Install the forks back on the bike. Align the forks on the axle for minimum bind. Tighten all bolts including the brake caliper bolts. If you have hydraulic brakes, pump them up and enjoy! | |
16 - TUNING NOTES To adjust the Gold Valve Emulator you must remove it from the fork. When you remove the fork springs use a twisting motion to avoid oil drips. To remove the Emulator, use a parts grabber. Adjust the Emulator Valve Spring Preload a half turn at a time. More Valving Spring Preload will make the forks stiffer. Before installation, be sure the jam nut is tight. | |
Brake Arcing - cutting the drum | 17 - DRUM BRAKES - Vintage Call for details. FRONT WHEEL INSTALLATION with a DRUM BRAKE Most front axles tighten into the left fork tube. The right side has a pinch on the axle that allows the fork tubes to be aligned. Your bike may be reversed from this.
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18 - VENTED FORK CAPS - Vintage Found on European forks in the early 70s. This was not a great idea. If your forks are vented there is typically a hole in one of the flats of the hex or on the top. We suggest you drill and tap the vent hole and plug it with a set screw. (I am looking for a picture of one of these. If you can help it would be appreciated.) |