Race Tech Fork Springs

[Spaceteach]

Just thought I'd post a heads up about an issue I ran into while installing Race Tech fork springs.
Yesterday I installed the Race Tech Gold Valve Emulators and springs in my forks. Overall the installation went well. Removal of brake caliper, wheel and fork tubes was easier than I thought it would be. Drilling 4 new holes and enlarging two existing ones in the damping rods was tedious, but not difficult and so was cutting the spring spacers to the correct length (my tubing cutter really sucks). Went to re-assemble the forks and discovered that the washers that came with the springs were too large to fit in the fork tubes. The Race Tech instructions basically tell you the the world will come to an end unless you put one washer between the top of the spring and the bottom of the spacer and another washer between the top of the spacer and the bottom of the fork cap. When I tried to drop the washer into the fork tube it wouldn't clear the threads at the top of the tube. I then compared them to the Honda washers I had removed and sure enough they were a couple millimeters larger. I couldn't just use the Honda washers because they only use one per fork tube while the Race Tech install calls for two. Luckily I found an old sanding drum mandrel that was the same size as the internal diameter of the washers. Put the washers on the mandrel, chucked them up in the drill press and held a file on each side of the washers to file them down. Had to go really slow to avoid melting the rubber on the mandrel I was using but eventually I got them small enough to fit.
After I finally got the washers in, the rest of the installation went smoothly.
As a heads up, one thing I noticed after I got the washers into the fork tube was the tube seemed wider below the threads. I think if I had just filed a flat on opposing sides of the washers so they would clear the threads they may have fit inside the tube. That trick wouldn't work on the upper washers that go under the fork cap since they have to go in straight, but the Honda washers could have been used for that location.
I don't know if all the fork springs from Race Tech come with those washers or I just got a kit with oversize washers, but I thought I'd post this just in case other forum members run into the same problem.

I've only had a chance to take a short ride today, but initial impression is the Race Tech stuff is a Major improvement

Bob

 

[Hmcp88]

Can't wait to do mine now you got me excited!

 

[Beemerphile]

I can see the world ending abruptly if you left out the washers between the springs and spacers, but between the spacer and the top cap, I don't get it.

 

[Spaceteach]

I can see the world ending abruptly if you left out the washers between the springs and spacers, but between the spacer and the top cap, I don't get it.

I don't either, but the instructions were explicit. Exact verbiage= NOTE: You must have washers on both ends of spacer. The spacer must not rest directly on the spring or the cap. They even underlined the second sentence.

Bob

 

[670cc]

Bob, I'm glad your installation went fairly well. I'm curious how you chose to set you emulators as a first pass. The instructions give you some guidelines but in the end you just have to guess at a starting point.

On mine I used the softer emulator springs, preloaded to two turns. I also drilled one extra 1/8 inch hole so three out of the possible four holes are open. I tend to lean toward a softer touring type ride, plus I weigh a little less than the "average" rider, from what I can gather.

 

[Spaceteach]

Greg,
I called Race Tech as soon as the emulators and springs got here to get their suggestions on initial settings. Here is what their tech support recommended for my weight of 170 pounds and what I used.
Gold Valve Emulators - blue springs with 2 turns of preload, 2 holes
Fork Oil - 15wt. Filled to 120mm from the top of the tubes. Web site lists 90mm but tech support said they are now setting it at 120.
The rest of the settings were per the instruction sheet which included drilling the existing 2 holes in the damping rod to 5/16 inch and drilling 4 more 5/16 holes 90 degrees from the originals. I drilled 2 of the 4 holes 10 mm below the existing ones and the other 2 were 10mm above. Fork spring preload was set to 19mm. I was trying to set it at 20mm but by the time I finished off some rough ends where i made the cuts on the spacers, it came out to 19. The spacer length ended up being 191mm.
The only variance from the Race Tech recommendations were the fork springs themselves. Before ordering I called to ask the recommended spring rating for a 170 pound rider and was told .80kg. I had previously read the posts by Beemerphile and Loomis, and since they had used .85 and .90 kg springs I decided to go a little firmer and ordered the .85 rating.

Hope this helps,
Bob

 

[Beemerphile]

I don't either, but the instructions were explicit. Exact verbiage= NOTE: You must have washers on both ends of spacer. The spacer must not rest directly on the spring or the cap. They even underlined the second sentence.

Bob

Understand. I would have done as you did.

 

[670cc]

Good info, Bob. Thanks!

Greg

 

[Spaceteach]

I can see the world ending abruptly if you left out the washers between the springs and spacers, but between the spacer and the top cap, I don't get it.

Lee,
I started thinking about why they wanted the washer between the top of the spacer and the fork cap, so I just measured the spacer material I had left over. The tubing Race Tech supplies to cut the spacers from is 32.8mm in outside diameter with a wall thickness of only 1mm. The bottom of the fork cap isnt solid like the end of a bolt, it has a cup machined into its center. I'm wondering if they weren't concerned that the spacer could possibly work its way into the cupped portion of the cap and royally screw up the preload. The washer has a smaller inside diameter than the cup in the cap, so maybe its purpose is to keep that from happening, or possibly it's just there to protect the end of the really thin walled aluminum spacer tubing. At any rate, I figured the folks at Race Tech probably knew what they were doing when they wrote the instruction to include it (even if they did supply washers that were a little to large to fit past the threads at the top of the fork tube )

Bob

 

[DanWill]

I just assumed that since the spacer is a thin hard metal and the fork cap is aluminum, that they require the washer to keep the spacer from digging into the softer cap...

 

[Spaceteach]

Actually I think the spacer is a softer aluminum alloy than the cap. When I first saw the spacer material I was afraid the cheap pipe cutter I have would damage it while I was trying to make the cuts. Actually ended up making a miter box and using a small X-Acto hobby saw to cut the spacers. I think the saw blade was something like 60 or 80 teeth per inch and it had no trouble cutting through the spacer material.

Bob

 

[DanWill]

No, the spacer wouldn't be made out of anything soft. If it was, it would deform when weight was put on it.

 

[captdirt]

I installed mine yesterday and reused the stock springs. No washer on top of the spacer. Must have something to do with the spacer material from RaceTech. Now just add some of these and we'll have real live motosickle forks.

 

[Spaceteach]

Glad to hear the installation went well for you. I'm pretty sure you're correct about the spacer, especially since Honda doesn't use one. FWIW the piece of tubing Race Tech supplied was stamped ALCOA seamless in ink, the section of tubing was long enough to cut about three spacers the same length as the stock one, and the whole piece weighed less than one of the Honda spacers.
I'm not really getting all fired up about the EBay preload adjusters. I'm pretty happy with the Race Tech recommendation for pre load and doubt I'd be adjusting it anyway. Now having said that, if I ever needed to replace the fork tube caps, those are the ones I'd order.

Bob

 

[ray]

May I confirm the spacer dimensions are 32.8mm OD and 20mm length, and that it's cut from the supplied tube rather than cutting the original?

 

[Spaceteach]

May I confirm the spacer dimensions are 32.8mm OD and 20mm length, and that it's cut from the supplied tube rather than cutting the original?

Not exactly. First, if you are installing just the Race Tech emulators, i believe the instructions say to measure the thickness of the emulator and cut that amount off of the original spacer. The 20mm measurement is for the pre-load. The spacer length will be quite a bit longer than that, but i dont know the exact length since I installed the Race Tech springs and they are a different length than the originals. Race Tech does not supply spacer material with the emulators, that only comes with their fork springs. If you are installing emulators AND Race Tech springs, you use the spacer material they supply with the springs. The spacer length depends on how much pre-load you want, and the instructions tell you how to calculate the correct length. In my case, to get 20mm of preload, the spacer length was 192mm, but the Race Tech springs are shorter than the original Honda. 32.8mm was the outside diameter of the spacer tubing Race Tech included with the springs. I think the original Honda spacer was a little larger in diameter, but I never measured it.

Hope this helps,
Bob

 

[ray]

Thanks Spaceteach, clearer now. Let me go through the instructions a few more times.

 

[westgl]

I bought a Racetech fork spring kit, for a Suzuki I have same thing, washer were to large,

Also the tube they sent was a very cheap alum. tube, that did not look very durable.

The washers are for preload, some guys were adding extra washers some guys only one, I went to the hardware store and picked up some grade 5 washers the correct size & thickness to fit.

 

[DanWill]

I think I may just leave my spacers the same length to bump up the preload, instead of cutting them to compensate for the size of the valves... I'm keeping the stock springs as they seem to be a good match for the weight of the bike and my 190+ pounds. I just want to get rid of the hammering on larger bumps.

 

[Spaceteach]

I think I may just leave my spacers the same length to bump up the preload, instead of cutting them to compensate for the size of the valves... I'm keeping the stock springs as they seem to be a good match for the weight of the bike and my 190+ pounds. I just want to get rid of the hammering on larger bumps.

If the spring rate is a good match now, I imagine they will be too firm with the extra preload. Of course you can always try it full length and, if its too firm, cut down the spacers until you get the feel you like. With full length spacers, compressing the spring far enough to screw on the fork caps may be a bit of a challenge. Spacer length/preload calculations are beyond my limited comprehension, so I just went with the Race Tech recommendations. Even had issues following the instructions. I must have cut those spacers 6 times and they were still too short.

Bob