Fitting Racetech Gold Valve cartridge emulators

Please share your secrets! What mods have you made to your TRX?

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Rubes
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Fitting Racetech Gold Valve cartridge emulators

Post by Rubes » Fri Nov 19, 2010 1:20 am

I was feeling flush so treated myself to some new fork springs and gold valve emulators for my standard TRX forks. I'm unclear on the instructions and just want to confirm with anyone who has done this previously I've got the right end of the stick before I start anything destructive. :oops:

Firstly does anyone know if the damper rod is different for Japanese home marked models? I know there are some differences in the forks. I have a spare set of damper rods that I got of ebay but no idea what model they came from.

The emulator doesnt quite fit the top of the damper rod. It looks like the damper head needs to be machined out a few mil. Is this correct or do I have the wrong part - part numbers seem to match the website? If I do have to machine out the head I assume that you can still get the damper rod out at a later stage as there will be enough of the pattern left to get a purchase?
I assume I remove the internal circlip and break out the plastic sleeve with a screw driver?
Image

The compression holes need opening out and two news ones added. Easy enough. I'm less clear on what needs doing with the damping rebound side of things. I think I need to braze up the four small holes around the head of the rod as well as the one slightly larger one just below them. Then I'm really confused by the step to re-add a new rebound hole. Can't I just leave the existing one in place? The destructions talk about drilling a new hole the same size as my current prefered settings. I have it set to 4 on the adjuster but no idea what sized hole this equates to.
Image

Also someone previously mentioned there was a code on a sticker in these kits to access the DVS section of the racetech site to get special tuning settings. I have checked everything in there and there is nothing suitable. Any clues as to where this code is supposed to be?
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by HansJ » Fri Nov 19, 2010 4:52 pm

Long time since i did this, but i followed the instructions below (courtesy Bob?) which can be found with all the pics in:http://autos.groups.yahoo.com/group/trx/files/

There's one attached picture in the bottom of this post.

I didn't buy these new, so i have no clue about the RaceTech site and tags, sorry

*****************************************************************

FITTING RACETECH GOLD VALVE EMULATORS to the YAMAHA TRX850

1. Remove front wheel & brake callipers.

2. Loosen the fork caps about half a turn only.

3. Loosen the allen bolts which hold the damping rods in place about one turn each. These are located under the bottom of the forks and can be real mongrels to loosen. At worst you may need a rattle gun.

4. Loosen the handlebar clamps, top triple clamps and bottom triple clamps, then remove the forks.

5. Taking care to avoid swapping bits between legs, disassemble the fork by removing the fork cap, the top washer, spacer, bottom washer & spring. Empty the fork oil into a suitable container (about 500ml minimum) by inverting the fork, then pumping it until all oil is expelled. Then remove the allen bolt and copper washer from underneath the bottom of the fork, and the damping rod should drop out the top.

6. Repeat the process on the other fork, taking care to mark the components and leg to avoid swapping bits between forks.

7. Disassemble the damping rod by removing the spring clip which holds the damping valve into the top of the rod, then withdraw the damping valve, it's detent spring and detent ball. The valve, detent spring and ball are of no further use.

8. Braze up the three detent holes and the one oil feed hole. Dress up any brazing dags on the outside for a completely smooth finish, and inside if there is any risk of bits falling off. Do not alter the original rebound hole. Drill four new 8mm compression holes as per the photo, and enlarge the two existing compression holes to 8mm (they are about 6mm as standard), and chamfer the edges both inside and out.

Note that it is important to stagger the holes in order to avoid weakening the bottom of the damping rod - it carries the full weight of the bike via the spring.

9. Cut off the damping adjustment shaft just below the bottom of the fork cap.

10. Drop the damping rod back into the fork along with the spring, then screw the fork cap back on loosely. Invert the fork, press down as firmly as possible against the spring pressure and replace the allen bolt and copper sealing washer using a suitable thread sealant to lock the assembly.

11. The following instructions pertain when using the Ohlins 8604-80 springs which I believe are not actually intended for the TRX850 but which, when used in conjunction with Gold Valve emulators are a more suitable length than the recommended Ohlins spring. The added length of the emulator means that the recommended Ohlins spring is too long and would thus result in excessive preload. The emulator used is the “Race Tech FEGV S4101 Gold Valve Cartridge Emulator”

12. Using 31mm OD 3mm wall thickness PVC pipe (as used for plumbing purposes) cut two spacers to 70mm length each using either a tubing cutter or a mitre box to ensure the ends are square and clean. If your ends are not square there is a likelihood that the wall of the spacer will deform and the spacer may collapse.

13. Set the preload on the Gold Valve emulator to two turns on, using a thread sealant to lock the thread. Fit the supplied spring clip to the bottom groove of the emulator – this ensures that this model emulator is a snug fit inside the top of the TRX damping rod. Drop the emulator (nut side down, allen bolt side up) into the fork and shake the fork to encourage the emulator to seat into the top of the damping rod.

14. Pour about 300ml of fork oil (I suggest about 15 or 20wt) into the fork, then pump the fork up and down until all air is expelled and the oil has fully infiltrated the bottom chambers of the fork. Then with the fork fully compressed, top the oil up to 110mm from the top of the fork tube (more or less according to your preference).

15. Note here that the level of oil in the fork tube has a very significant affect on springing because as the fork compresses, the air trapped in the top of the fork compresses, thus acting as an air spring. Too low an oil level (and thus too much air gap) and the forks will bottom out too easily; too high an oil level (and thus too little air gap) and the spring action will become too strong as the suspension nears full compression. About 110mm from the top of the tube works fine for me (at about 90kg bodyweight) with the Ohlins 8604-80 springs. Note also that the emulator controls compression damping while the flow of oil back through the original rebound hole in the damping rod controls rebound damping. To alter compression damping you increase the spring preload using the allen bolt on the top of the emulator. To increase rebound damping you increase the thickness (viscosity) of the fork oil.

16. Drop in the spring, then with the fork partly compressed, rotate and shake the spring until it seats properly on the top of the emulator.

17. Drop in the first flat washer, then your new spacer, then the second flat washer. At this point the second washer should be just a few mm below the top of the fork tube (with the fork fully extended). If the top washer and part of the spacer are standing above the top of the fully extended fork tube, then either the emulator is not properly seated in the top of the damping rod, or the spring is not properly seated on the top of the emulator. Fit the top cap to the fork and tighten it finger tight.

18. Repeat the assembly process on the other fork leg, then refit the forks into the bike.

19. Replace the fork into the triple clamps and tighten the top triple clamp only quite firmly and tighten the fork caps.

20. Now you need to align the front end components to prevent any binding as the forks compress. With both fork legs fitted and with only the top triple clamps tightened firmly, refit the front wheel (but don't tighten the axle, just make sure that the axle threads are well engaged) and refit the brake callipers.

21. Drop the front wheel back onto the ground, sit astride the bike, apply the front brake and bounce the front end firmly a few times.

22. Now tighten the bottom triple clamp bolts, then the axle bolt & pinch nut, then the handlebar clamps, then refit the front mudguard and you're done.

23. Some useful measurements:
A 110mm air gap uses about 440ml of oil per leg, but this is approximate and depends on just how empty all the chambers in the fork leg were when you started.
The two flat washers are each 2.5mm thick.
The spacer is 70mm long and is made from 31mm OD 28mm ID. The stuff I used is branded “IPLEX PIPELINES PRESSURE 31” in NZ. I would describe it as PVC but that may not be chemically correct.
The emulators are 33.5mm OD, and the “shoulder” (which stands between the top of the damping tube and the bottom of the spring) is 20mm tall.
Total stack height of the internals is 510mm being the emulator (20mm), spring 415mm), spacer (70mm) and two 2.5mm washers (together 5mm).
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Sun Nov 21, 2010 11:59 am

Rubes I noticed your instuctions say drill 2 new 8mm comp holes and expand the other 2 holes from 6mm to 8mm... this seems to differ as per section 8 stating expanding the 2 holes from 6 to 8 mm plus drilling 4 new holes... Or am I just reading something wrong :) :)
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by Rubes » Mon Nov 22, 2010 12:34 pm

You need three sets of holes in total. My spare dampers have two 6mm sets already. This seems to differ from the part used in the yahoo group instructions which only has one set. It's a bit of a concern for me as it also isn't mentioned that the damper head needs to be machined to allow the gold valve to fit properly. Perhaps my ebay part is not right. I haven't opened up the front forks yet to verify exactly what is on the bke.
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by HansJ » Mon Nov 22, 2010 1:00 pm

I did not machine anything on the damper rods. In what way do you mean they won't fit? Do you have the Japanese spec forks? IIRC those forks were thinner. A fellow TRX rider had some problems making his Goldvalves fit, but i can't remember if he did anything to make them fit. We both have std European forks, i.e. 96 or later. I got mine second hand (never fitted though), and they had been on the previous owner's shelf for many years. my friend bought his new, so maybe something has changed over the years.

Edit: I checked through some of my old PMs, and it seems he had to turn the diameter of the emulators a couple of thous. Not sure whether it was the overall diameter, or just the lower part that fits in the rod itself.

Edit2: might bebetter off contacting himn, he's a member here:
http://trx850.motomaniac.net/forum/memb ... ile&u=1471
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by dandywarhol » Mon Nov 22, 2010 5:29 pm

I ground out the inside "serrations" in the damper rod on my TDM850 damper rods - the emulators were just a little bit too big. The TDM900 was different - a circlip holds the damping adjuster ring in - just removed the circlp and prised out the plastic ring.

Instead of brazing up the 4 adjustment holes you could get a ring made up to fit snuggly behind the adjuster holes - that'll keep the oil from flowing through them :D
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

Rubes
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by Rubes » Wed Nov 24, 2010 4:06 am

Well it might be that my dampers are not legit. I'm suspectinging they may well be TDM ones now. I will have to wait till I get more time to take the bike off the road and then I'll compare the dampers. I was hoping to do the work up front on these spares and then just do a quick change over but I reckon I'll need to have a looksee at what is currently in the forks now. :cry:

Don't suppose anyone has a set of guaranteed TRX Euro or Australian spec damper rods lying around that they could take a pic of?
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Wed Nov 24, 2010 5:28 am

I think I got a few bent ones under mums place from original std aust silver based forks..I'll have a shoofty as there under the house at mums. :wink:
These where rebuilt from black based forks back into the silver bases and I've blow a seal on those now so I have my spare forks inplace at present.
I want to do the same gold valve mod myself so if the black based forks are from Japanese import model then that rules pics from those and maybe mods to those damper rods myself...
AAAAHHH the plott thickens :lol: :lol: :lol:
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Thu Nov 25, 2010 3:38 am

I knew I had them somewhere. the forks are bent at a 30 degree angle but the damper rods are ok I just need to cut the legs to remove them as they cant be removed from the bottom of the fork legs. Get back to you ASAP
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Thu Nov 25, 2010 7:34 am

8) people are looking at me strange as i flip my toe slider up for the ariel and talk into the sole of my boot. Mission accomplished chief,you know we should be doing this in the cone of silience :roll: but I'm waiting now for the sexy agent 69 ...Stella from MY FACE RACING to come home and take some pics with her trusty vowel phone but the rods are straight and I know are the original std aust model damper rods before the first front end rebuild.
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by dandywarhol » Thu Nov 25, 2010 1:08 pm

Anyone in the UK got a spare set of damper rods? I would like a set to modify for emulators and just change them over as a replacement?

Cheers
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Tue Nov 30, 2010 7:16 pm

Rubes wrote:Well it might be that my dampers are not legit. I'm suspectinging they may well be TDM ones now. I will have to wait till I get more time to take the bike off the road and then I'll compare the dampers. I was hoping to do the work up front on these spares and then just do a quick change over but I reckon I'll need to have a looksee at what is currently in the forks now. :cry:

Don't suppose anyone has a set of guaranteed TRX Euro or Australian spec damper rods lying around that they could take a pic of?
Rubes You still chasin those pics???? Janet has them on her I phone . Can e mail them to you but look the same to me... Measurements across the top at the widest point where the cartridge sits is 30mm but all the other holes as such look in the same position etc.
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by cobbadiggabuddyblooo » Tue Nov 30, 2010 7:25 pm

Designated emulator for a 99 model trx 850 in Australia from RACETECH after e mailing them I was advised FEGV S4301, FRSP S3534090
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Re: Fitting Racetech Gold Valve cartridge emulators

Post by Con Rod » Sun Jan 13, 2013 2:16 pm

cobbadiggabuddyblooo wrote:Designated emulator for a 99 model trx 850 in Australia from RACETECH after e mailing them I was advised FEGV S4301, FRSP S3534090
Ok, so the Race Tech valve emulator you need is not FEGV S4301. This is the one I ordered. The emulator diametre needs to be 35.3mm but the diametre of FEGV S4301 is 36.1mm. Also the botom of FEGV S4301 will not fit into the damper rod at the diametre needs to be 28.1mm and on FEGV S4301 it is 29.3mm.

However you can turn the emulator down to size on a lathe or by spinning it in a drill and filing it down to size

EDIT

Further information added below:

If you look at the picture below you can see there are 2 diameters which matter, the main body of the emulator and the collar at the bottom which sits into the damper rod.
1.jpeg
both the main body of the emulator and the collar at the bottom which sits into the damper rod were too large, as shown below:
2.jpeg
3.jpeg
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Paul

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Re: Fitting Racetech Gold Valve cartridge emulators

Post by Con Rod » Mon Jan 14, 2013 3:13 am

So what I needed to do was take about 1mm off both diametres so it would all fit.

What I did was put the emulator in a drill to spin it and then filled it down and sanded it smooth so it would fit, as shown below:
5.jpeg
4.jpeg
below is a before and after:
6.jpeg
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