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Gold Valve Emulator

ccolwell

Member
First of all, you shouldn't take any of my advice here because I am a mediocre mechanic at best. More than one project has ended up at a dealer to fix my mistakes. In fact, I wouldn't take my own advice but when I'm out in the garage, there's no one else to ask. Second of all, I'm only half way through the project and I won't find out how well it works until April. If I'm lucky.

Still, as I've spent some time on this and emailed with RaceTech several times, I thought I would share what I (may) have learned. First, the package is labeled NV for No Video. It turns out there isn't a video and the labeling is for internal consistency.

Second of all, and more importantly, the instructions, which are otherwise quite good, are not specific for BMW's. The product is sold for 70-92 airheads and there are a number of differences in the forks over that period of time. There are some brief comments/instructions on the web page, here
http://old.racetech.com/evalving/en...&year=70-92&TABLEINFO=street&langname=english

However, I emailed Mat Wiley, listed as the "Vintage God" on RT's website and he sent me some different instructions. If you decide to install these, email Matt yourself as I am not going to claim I understood him perfectly. I'll show you what I did do based on my emails with him.

I'll break this into a few posts to get the pictures in. Break out your Clymer manual and compare to the pictures in there.

When you disassemble the forks, you probably don't need to create a tool as the Clymer instructs -- the bottom nut under the rubber cover will loosen with a socket if the spring is still installed (Edit: I did end up making the tool to make sure it was tight enough on reassembly). Once you remove the fork leg, you also do not need to take out the circlip and the two threaded spacers with a non threaded spacer from the fork tube. However, I would. Like me you might find this:
 

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Indeed, you might want to buy a couple of these bushing/spacers before you start. The one on the other fork was not broken, but didn't look good. It's supposed to look like this. Edit: the Clymer manual does not show this in its disassembly/reassembly instructions.
 

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After two emails checking that I had it right, I opened up the four compression holes at the bottom of the damping rod to 1/4" and added two more 1/4" damping holes just above those. I asked and was told to leave the holes that are slightly higher on the rod alone. While it looks like that would weaken the tube, the tube is thicker internally where I drilled the new holes. The ball in the picture is a check valve that bottoms out between the lower and upper holes (here, left and right). The ball and spring should be discarded. Edit: ultimately, this was not sufficient. You need to add a third set of holes above (to the right in the picture) as shown in the kit instructions.
 

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The instructions on the website say to drill a 5/16" hole through the top of the damping rod. Matt suggested simply cutting off the top of the rod just below the rebound holes. I didn't like that idea as it would prevent me from ever disassembling the upper part of the rod which holds the top out spring and some thin rings that seal the tube (no, I have no idea why I'd ever want to do that, still...). However, the hole I drilled was off center, so I split the difference and cut the nut off the top. That way I can still use a drift through the holes to unloosen the part.
 

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Lastly, you need to make a spacer out of PVC pipe to fit between the emulator and the damping rod. You simply need to make sure the lock nut on the bottom of the emulator is clear of the top of the rod. RT sends some PVC tubing with springs, if you buy those as well. It may not be enough to make these spacers and the preload spacers for the springs, but that's tomorrow's project. I am taking my good time doing this. Being unemployed at least has some benefits. Per my emails with Matt, I also have to check the preload on the emulator spring -- note you can adjust the damping by changing the emulator spring (that blue spring on top of the gold doohickey, excuse me, emulator) and/or preload.

BTW, click on the fork springs link on the web page above and then use the calculator to check what springs they recommend. The check the stock fork spring rate. I've never seen anything that soft. My 900SS had something like .55 stock and they were very soft. I put .85's in the Duc and it was lighter than the R90S.
 

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I'm still wondering how to clean out the inside of the damping rod thoroughly to make sure I have all the debris from the drilling. I don't have a parts washer and just spraying carb cleaner and WD40 through the center is not gving me that warm, fuzzy feeling of confidence. Any suggestions?
 
Looks like a good installation. Congrats!

I recently rebuilt the forks on my SV650 with Traxxion damper rods, emulators & springs. The results were much more than satifactory. You'll be happy with the improvement!
 
I'm still wondering how to clean out the inside of the damping rod thoroughly to make sure I have all the debris from the drilling. I don't have a parts washer and just spraying carb cleaner and WD40 through the center is not gving me that warm, fuzzy feeling of confidence. Any suggestions?

Didn't see this.

After employing carb cleaner, as you indicated, I actually washed mine out with soap & water and then thoroughly dried them with towels and a blow dryer. Seems to have worked.
 
I'm still wondering how to clean out the inside of the damping rod thoroughly to make sure I have all the debris from the drilling. I don't have a parts washer and just spraying carb cleaner and WD40 through the center is not gving me that warm, fuzzy feeling of confidence. Any suggestions?

Hi,
Dunk the ends (where you did the drilling) into a can of gasoline or diesel and swish them around???
 
Hi,
Dunk the ends (where you did the drilling) into a can of gasoline or diesel and swish them around???

Yeah, the problem is that the rod is hollow all the way through and I'm afraid the debris could have gone everywhere. If it weren't such a small hole, I'd push an oil soaked paper towel through.
 
Yeah, the problem is that the rod is hollow all the way through and I'm afraid the debris could have gone everywhere. If it weren't such a small hole, I'd push an oil soaked paper towel through.

What about using a rifle cleaning rod and patches?
 
Looks like a good installation. Congrats!

I recently rebuilt the forks on my SV650 with Traxxion damper rods, emulators & springs. The results were much more than satifactory. You'll be happy with the improvement!

I have Traxxion cartridges on my 600RR forks (a friend of mine built the bike and went all out). They seem fantastic, but then I'm kinda slow.
 
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Didn't see this.

After employing carb cleaner, as you indicated, I actually washed mine out with soap & water and then thoroughly dried them with towels and a blow dryer. Seems to have worked.

That's what I was thinking when I woke up. And, given the filings in the kitchen sink, it seems to have worked well. Hope the vague smell of fork oil and toxic cleaners goes away before my wife gets home tonight.

The rifle rod would be perfect, but I don't have one. Friends would, I think, so I may try that on the other damping rod.

Note: even after several apps of carb cleaner and WD40, there was a lot of crap around the top out spring and sliding bushing (you can just see it on the left in post #5 above, the bushing is the silver piece). You need to slide that back and forth to clean it out. Edit: not a top out spring; a blow off valve for one of the damping circuits (rebound, I think).
 
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Nothing interesting to report on fitting the springs, other than measure twice and think thrice before cutting the preload spacers. There was plenty of PVC (in the spring kit) to make all four spacers.

And I have what I believe to be a set of Progressive springs. First dibs go to someone who will pick them up, second to someone who pays for shipping.
 
Update on this project: Once I got it all back together, the forks felt much too stiff. It felt as it I had simply replaced the stock 5w fork oil with 15w. This indicated that I had not defeated the stock damping system. Fortunately, Matt Wiley was at the NYC M/C show and I had a chance to talk with him (and I had my camera with me with the above pictures still on it). He suggested adding another set of holes in the dampng rod above the ones already drilled. Having done that, the fork now feels right. A ride report is still weeks away here in the Northeast.
 
When I was a kid and too poor to have a rifle cleaning rod... we used clean our rifles, and shot guns with a lengthy piece of twine and old piece of towel and pull it through... It worked and was easy to carry in the field. You can add a pull stick tied to the twine to add pulling power. We used a 3/4 X 3" piece tied to the twine.
 
When I was a kid and too poor to have a rifle cleaning rod... we used clean our rifles, and shot guns with a lengthy piece of twine and old piece of towel and pull it through... It worked and was easy to carry in the field. You can add a pull stick tied to the twine to add pulling power. We used a 3/4 X 3" piece tied to the twine.

Thanks, after doing each rod twice, washing them in the sink with soap and water proved very effective.
 
And now a ride report. It's taken a while as I experimented with changing the compression damping via the spring preload and the rebound via fork fluid. Ultimately, I ended up very close to RaceTech's suggested settings -- 2 turns of preload and 15w fork oil.

I am very pleased with results. To be sure, the ride is sport bike firm but with more than adequate bump compliance. The bike feels much more stable and planted in turns. I would do this again (especially since it would be much easier the second time).
 
Hey Gang, I am trying to wrap my head around the 15W fork oil. It seems extremely heavy for a 1972 /5 BMW. Is it due to the Widened holes on the dampener rod?

I put my forks together with the gold valve, added 15w, but haven't ridden the bike yet. The forks however feel extremely stiff. I'm going to take them apart today and make sure nothing is binding before i take it for a ride.

-josh
 
See my last post on the first page. If you're taking it apart again, might as well add some extra holes to the damping rod to make sure you have enough oil flow through there. You can't have too much as the Gold Valve will control the damping, but you do have to make sure you have completely defeated the stock damping circuit. And it will feel stiff in the garage, particularly if you put in the RaceTech springs. Just ride it and see how it feels.
 
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