Race Tech Gold Valve Fork Emulators or Fork Caps with Preload Adjusters , which one I should try ?
Both are nice but if you pick one go with emulators. Ideally you'd do emulators and springs, then prelaod adjustment of some type to get the sag set.
Both
:agree: they do two different things. Also agree that if you're only doing one, get the emulator
Proper spring rate, fresh oil, emulators. You can tune your preload with spacers or removing preload.
I first did a correct spring and incorrect fork oil and was a bit disappointed. Eventually did the emulator thing and lightened(?) up the fork oil, played with preload a bit. Waaaay better. I would say that rebound damping could be tuned a bit more.
I was surprised how well the emulators work. No worries with hitting all the choppy stuff on bad roads at speed.
What is it you're trying to accomplish?
may I suggest before you do anything you read the RaceTech "Motorcycle Suspension Bible" (available on RaceTech's website or you can find a PDF online).
I've installed the emulators in a few bikes. the ones from Mike's xs are copies, but good ones. I never bothered with adjustable preload, it can be set with spacers over the springs.
will do a bit of research, thanks so much
I've got the race tech emulators and progressive springs in my DS-7, set up for my weight and erratic riding style by a local suspension guru! They work way better than I expected. Paired with the hagon rears the bike works quite well for being 49 yrs old!.......................................D
Does anyone know if these Mikes XS emulators can be made to work on ACRDs? He calls out Daytonas but I seem to remember reading something about them being used on ACRDs as well with some modification, maybe on the old site?
Thanks!
https://www.mikesxs.net/yamaha-xs650-damper-valve-pr-front-forks-77-84-oem-1t3-23170-00-00.html (https://www.mikesxs.net/yamaha-xs650-damper-valve-pr-front-forks-77-84-oem-1t3-23170-00-00.html)
You need to make an adapter, so the emulator fits and seals on the top of the damper rod. The Race Tech ones come with it. Also, the damper rod on a RD400 needs to be modified by cutting the top off in a lathe because it is not open, I think RD350 rods are open on top so it doesn't need to be modified. The first pic is a unmodified 400 damper rod. The second one modified and ready to assemble.
(https://i.ibb.co/98hK5k2/em2.webp) (https://imgbb.com/)
(https://i.ibb.co/mz68qmB/em3.webp) (https://imgbb.com/)
Quote from: Djg8493 on March 13, 2022, 09:59:42 PM
Does anyone know if these Mikes XS emulators can be made to work on ACRDs? He calls out Daytonas but I seem to remember reading something about them being used on ACRDs as well with some modification, maybe on the old site?
Thanks!
https://www.mikesxs.net/yamaha-xs650-damper-valve-pr-front-forks-77-84-oem-1t3-23170-00-00.html (https://www.mikesxs.net/yamaha-xs650-damper-valve-pr-front-forks-77-84-oem-1t3-23170-00-00.html)
i have them in my 350. you have to split the pin per instructions but they work well.
(https://www.2strokeworld.net/wp-content/uploads/lightweight-rd/forks/IMG-20170207-00560.jpg)
Sorry to resurrect an old thread :smiley:
Just to be clear, these Mikes XS emulators can be made to work in the 34mm RD forks? I read through the Instructions, but I don't see any mention of "splitting the pin." Are there instructions hiding somewhere on the forum?
when you get it its obvious what you need to do. looking at the rod from the top, the roll pin is pressed all the way across the opening. take the middle section out, to clear the bottom of the bolt/nut that protrudes into the rod. a dremel with a carbide bit to cut it i think is what i used.
as a side note, i did add preload adjusters from economy on my bikes since the original post. mine is on the lightweight rd, its about 115? lbs lighter than a stock bike, so i had to tune mine lighter, i used 5wt fork oil and actually reduced the preload a hair. however, i've done this the other way as well. I know, for a fact, these make a huge difference (the emulators) when set up right. heres the instructions for the XS forks, which the top is different than the earlier 34mm forks.
https://www.2strokeworld.net/wp-content/uploads/lightweight-rd/forks/fork-valve-emulators-1.pdf
It's been a while since I have messed with emulators. If you don't want to mess with splitting the pin, you should be able to tap threads into the the outer piece and then use a dog point setscrew. The points go into the hole in the rod when the pin went.
Use oil resistant blue Loctite on the setscrews (243?? I think it is).
Quote from: m in sc on January 30, 2023, 08:15:41 AM
when you get it its obvious what you need to do. looking at the rod from the top, the roll pin is pressed all the way across the opening. take the middle section out, to clear the bottom of the bolt/nut that protrudes into the rod. a dremel with a carbide bit to cut it i think is what i used.
as a side note, i did add preload adjusters from economy on my bikes since the original post. mine is on the lightweight rd, its about 115? lbs lighter than a stock bike, so i had to tune mine lighter, i used 5wt fork oil and actually reduced the preload a hair. however, i've done this the other way as well. I know, for a fact, these make a huge difference (the emulators) when set up right. heres the instructions for the XS forks, which the top is different than the earlier 34mm forks.
https://www.2strokeworld.net/wp-content/uploads/lightweight-rd/forks/fork-valve-emulators-1.pdf
That damper rod in the instructions is the same as late model RD250 or 400. but on a 350 they really need a racetech adapter with piston ring IMHO.
they dont. i'm running a set. have been for years, no issues. :twocents: could you fit rd400 or uk 250 dampers? sure. but not necessary at all.
That plastic piston ring on the adapter makes it a real b*tch to get it in the fork tube. I had to make a little cone ring compressor out of aluminum sheet to get it to go in without applying force that made me uncomfortable.
IR8D8R
heres the thing. the ring is supposed to basically stop the leakage past the rod, which i get. but that leakage is a constant, albeit tiny, amount that can be compensated for by adjusting the valve. erego, the ring isn't needed. ;) .02
actually, thinking about it, you could lathe up a spacer with grooves around it , would basically do the same thing as the ring.
So let me see if I've got this right. Here is my 77 RD damper rod (at least I think it's the original). I cut and drill where I have it marked in red. Then with the end cut off I can get to the roll pin and Dremel it out of the passageway. Correct?
Quote from: m in sc on January 30, 2023, 04:15:19 PM
heres the thing. the ring is supposed to basically stop the leakage past the rod, which i get. but that leakage is a constant, albeit tiny, amount that can be compensated for by adjusting the valve. ergo, the ring isn't needed. ;) .02
actually, thinking about it, you could lathe up a spacer with grooves around it , would basically do the same thing as the ring.
You may be right, but most later damper rod forks use a diagonally split phenolic resin piston ring to reduce that leakage an an aluminum spacer that restricts leakage would probably add too much stiction. Measure the ID of those fork legs and if it's around 28mm, I think that a spacer with a GL1000 or GT750 piston ring would work fine with less friction than racetech plastic rings. In forks that already have a piston ring, the spaces is just a straight aluminum tube. They don't need both seals/rings.
but we're talking about early fork internals, and they work just fine with no ring, or valve. the valve is smaller than the top of the rod so i dont see it as being an issue. :twocents:
Here's a video how they work. This is how I understand how they are fitted to a 400. You have to make sure the emulator is sitting on the top of the damper rod and the two surfaces seal. The 400 needs a spacer because it is impossible for it sit flush after you cut the top off, like you marked in red. I think the diameter of the shoulder of the emulator is too big to fit down in the cut off damper rod to seal it. Once you make a spacer to adapt the two there is no need to seal the outside of the spacer to the inner diameter of the fork tube. The piston ring on the rod is doing that. You could put a o-ring seal between the flush surfaces of the spacer and the emulator, but if it is a nice fit, I don't see a need. On a 350, like the one in the vise pic, it fits nice, without any adaptor, other than the roll pin needs to be cut out of the way.
https://www.youtube.com/watch?v=j3QYZEQoN_M
FWIW, there is a ton of info (at least there used to be) on Racetech's site about emulators, all of it wasn't easy to find but it was there.
IIRC regarding "adapters" and cutting the tops off there was a specified "distance" they called out. I can't remember what it was or from where.
A while ago, I put emulators in a set of Kawi triple forks. Instead of modifying the top of the rod and using an adapter I machined a new top piece. Overall length of that was based off of that info on the RT site. How critical it is, I'm not sure. Here are some pics of the modified rods I did for the Kawi forks. I did quite a few of these for board members at the time.
(https://i.imgur.com/7G8qHdl.jpg)
(https://i.imgur.com/FIOrlPW.jpg)
(https://i.imgur.com/vZK0Fli.jpg)
(https://i.imgur.com/gIXQ5HF.jpg)
(https://i.imgur.com/4cg9cRb.jpg)
(https://i.imgur.com/AyXH2NK.jpg)
(https://i.imgur.com/tg51AFx.jpg)
(https://i.imgur.com/K6xDPv2.jpg)
(https://i.imgur.com/Jvq5ULU.jpg)
Also IIRC, actual RaceTech emulators came with a lighter preload spring for the top of the emulator to use with the RD. Clones from Mikes XS didn't have the lighter spring.
Hopefully someone on here can chime in about actual use on this.
So I guess if I order them (the Mikes XS emulators), I'll see better what you're all talking about. I've read through this thread (a couple times), read the instructions, and watched the video. My shriveled up retired brain is just barely grasping all of this...
Quote from: oxford on January 30, 2023, 08:57:39 PM
Also IIRC, actual RaceTech emulators came with a lighter preload spring for the top of the emulator to use with the RD. Clones from Mikes XS didn't have the lighter spring.
Hopefully someone on here can chime in about actual use on this.
i can
absolutely guarantee i have the lightest rd anyone has used the mikes xs emulators on, on rd350 shafts, which made tunign it way harder than you might expect. As said, they work fine, with the springs in them that came with them. also stock rd springs, which i felt was good for this application.. but probably not most.
In the pic up top, I turned them in about 1 full revolution after this was tested from the pic. keep in mind, fork oil weight
absolutely plays a role here as well , which i mentioned on page 1. It took a few days to get it sorted correctly, few adjustments on the spring, and 3 different fork oil weights...but i got it.
tuned in this order:
adjuster at lightest setting, 20 wt oil. too stiff to react.
10 wt oil, way better but still a bit skow to react over 'washboarding' road on rebound.
5 wt, a bit too soft on compression but liveable.
adjust valve spring. +1/2 turn, +1/2 turn, +1/2 turn, back off 1/2 turn.
in regards to the preload adjusters, which i bought later, after having the valves in for a few years, (remember, the valves add preload if you don't that height out of the spring spacers) so, i already had the preload already up by that amount. I actually measured the total travel of the adjusters, and cut 1/2 of that value off the spacers so that i could legitimately add or subtract where i had started from. wasnt a huge difference but it def was better. ( i actually took some preload out to get better static sag)
loaded sag is now at about 1/4 total travel and handles bumps nicely with no undulation. 5.5 oz per leg fluid. 200 lb rider, 241 lb bike.
Good to know about the emulator springs. Did you play with the slow speed bleed holes any?
Quote from: JBeasty on January 30, 2023, 09:03:16 PM
So I guess if I order them (the Mikes XS emulators), I'll see better what you're all talking about. I've read through this thread (a couple times), read the instructions, and watched the video. My shriveled up retired brain is just barely grasping all of this...
It's always easier to do something than imagine or explain it.
Quote from: oxford on January 31, 2023, 06:44:28 AM
Good to know about the emulator springs. Did you play with the slow speed bleed holes any?
i was prepared to if i needed to but nope, didnt feel it needed anything aside from opening up the larger ones in the bottom.
Quote from: oxford on January 30, 2023, 08:54:31 PM
FWIW, there is a ton of info (at least there used to be) on Racetech's site about emulators, all of it wasn't easy to find but it was there.
IIRC regarding "adapters" and cutting the tops off there was a specified "distance" they called out. I can't remember what it was or from where.
A while ago, I put emulators in a set of Kawi triple forks. Instead of modifying the top of the rod and using an adapter I machined a new top piece. Overall length of that was based off of that info on the RT site. How critical it is, I'm not sure. Here are some pics of the modified rods I did for the Kawi forks. I did quite a few of these for board members at the time.
(https://i.imgur.com/7G8qHdl.jpg)
(https://i.imgur.com/FIOrlPW.jpg)
(https://i.imgur.com/vZK0Fli.jpg)
(https://i.imgur.com/gIXQ5HF.jpg)
(https://i.imgur.com/4cg9cRb.jpg)
(https://i.imgur.com/AyXH2NK.jpg)
(https://i.imgur.com/tg51AFx.jpg)
(https://i.imgur.com/K6xDPv2.jpg)
(https://i.imgur.com/Jvq5ULU.jpg)
I think I'm gonna drill my holes like you did, 4 of them staggered, and leave the 4 that encircle the rod in a straight line alone. I'm afraid if I tried to enlarge them it may weaken the rod.
One a side note - I just joined my local "Makerspace." They a have huge old Southbend lathe, and a Bridgeport mill. Plus MIG & TIG welders, and any other metal working tool you can think of. Plus lots of other stuff I'm afraid of... AND, they have people who will help you learn how to use it all! $50 a month. 2 miles from my house. Watch out!!
The rods are in compression. Even with some holes they are capable of holding relatively massive loads compared to what a motorcycle will exert while operating.
So, what does this actually do to improve things?
Quote from: Striker1423 on February 08, 2023, 08:36:17 AM
So, what does this actually do to improve things?
If you mean adding emulators, it apparently enables you to adjust compression damping (with the little spring tension), and rebound damping (with oil weight) individually. I say 'apparently' because I don't have any experience with them. But if Mark says they work, I'm all in :haw:
I'm by no means the expert, but they worked for me for sure. it controls the flow of the fork oil better than just the drilled holes.
Quote from: JBeasty on February 08, 2023, 12:49:47 PM
Quote from: Striker1423 on February 08, 2023, 08:36:17 AM
So, what does this actually do to improve things?
If you mean adding emulators, it apparently enables you to adjust compression damping (with the little spring tension), and rebound damping (with oil weight) individually. I say 'apparently' because I don't have any experience with them. But if Mark says they work, I'm all in :haw:
It's more to it than that. The compression damping curve is improved, i.e higher low speed damping forces, and lower high speed damping forces. This cannot be achieved with the stock (or even modified) fixed orifices
^ with the valve in the flow path, it will somewhat proportionately react to the speed of the movement as well. this can be dialed on my tightening or loosening the spring.
I don't have a great explanation, but that's about all i have.
I read through this a couple times, pretty much explains everything they claim to do.
https://racetech.com/page/title/Emulators-How%20They%20Work
Quote from: JBeasty on February 08, 2023, 12:49:47 PM
and rebound damping (with oil weight) individually.
If you look at the pictures I posted earlier you will see a weld spot on the rod and another pic with a small hole drilled. This was done to "adjust" (change) rebound, the original hole was welded shut and a new smaller hole drilled.
I did the hole size based on recommendations off one of the triple boards.
so, I actually rode mine in to work today, its been a few mos. My commute, in sections, has washboarded roads, some big truck tire indentations and I cross 2 sets or failroad tracks, one at about 30 degrees at the top of a hill, so not ideal in some spots. trying to be objective riding it.. its not cushy, but is def responsive wot feel stable and safe. one section of flat road i did take it up to about 90 mph and felt really good. I'll be honest, would it be better if it was a -hair- softer, probably, but not really super necessary. I have a big fzr1000 rotor and a blue dot caliper, and hitting the brakes hard compresses the forks at speed about 2.5-3"
DSVR described a "digressive" damping curve. It's basically what all good dampers do. You want "platform", basically chassis support in low velocity movements. However, on a big hit you want it to deflect. That's a pretty simplified explanation, but it works.
Rebound is easy, it's based almost strictly on spring rate as it is more or less a known quantity, as a result it's not that sensitive.
rebound is also controlled by fluid flow, and can be manipulated with a 2 step valve on these forks but thats way overkill in this application. the return holes in the legs will control this though.
some modern sport bikes will have rebound adj on one fork, and dampening adj on the other as weird as that sounds. its important as it will keep the front end planted better as well.
Rebound is an amazing tuning tool, probably the most valuable of them as far as dampers are concerned (lots of nuance to be explored in this realm). However, these ancient forks suck so bad that we need emulators and we aren't even worried about rebound. Even a lot of very high level dampers still use orifice style flow adjustment (looking at you, Ohlins) and it is just wrong. They do all sorts of weird stuff. That's partly why emulators work so well.
I use racetech valves in my race forks and they gave me a huge improvement.
The pictures above are perfect to show the modifications and the adapter.
This has been covered in various answers, I will try and share my experience with installing and tuning emulators..
Fork Springs are a VERY IMPORTANT part of getting the front end right.
the stock damper rod uses fixed-diameter orifices, which means they are not speed-sensitive.
First, understand standing what each component does.
The spring holds the front end of the bike up (I use straight-wound springs) the more the bike and rider weigh the stronger the spring you need.
Compression damping absorbs the energy of a bump and also controls the rate of spring compression during braking and at times both.
Rebound controls the release of energy stored in the compressed spring as the front end rebounds from a bump or braking or a combination of both.
The gold valves provide speed-sensitive compression damping through a combination of a washer stack and an adjustable spring with rebound damping being controlled by the weight of the oil. the more you tighten the spring the more it restricts the flow of oil during fork compression. Too much compression damping will lead to post-bump chatter, this can be while straight up and down under braking or leaned over in a corner (VERY SCARY). Not enough can lead to over-compression (front-end dive) under braking.
The reason the damper rods have to be drilled out is that the existing compression damping system must be eliminated, it uses the smaller diameter holes to restrict oil flow BUT it provides very little in the way of speed-sensitive damping, speed meaning the rate of available flow to adjust for the speed at which the forks are compressing.
You can see the small diameter bleed holes at the base of the damper rod, these get drilled out to 5/16"/8mm. My forks use Daytona damper rods which do not have the flow restrictor on the top of the rod, they are the same as the RZ350 with an open top and RZ350 emulators drop right in.
There need to be 3 sets of larger drilled holes through the damper rod. On most forks, there are two smaller sets at the bottom about 10mm apart and at 90 degrees to each other. a 3rd set is drilled the same distance above at 90 degrees to the top set (use a pilot drill to add the 3rd set or you will have an issue drilling them straight. They don't have to be perfectly aligned, they are there to pass as much volume of oil as possible up to the gold valve.
NOTE THE HOLES NEED TO BE WELL DEBURRED, drilling through the tubing will leave some nasty burs that can fall off later (I use a dremel with a small ball end burr)
For the early damper rods and 400 damper rods an adapter that seats on top of the rod and provides a nice flat surface for the emulator to sit on is all that is needed. the spring seats on top of the emulator holding it in place.
As was previously stated if the top of the damper rod is open and the same ID as the steel rod this is all you need together with the adapter. 400 Damper rods other than Daytona) need to have the top cut off. While doing it on a lathe makes for a nice even cut it is not absolutely necessary as the emulator sits on top of the adapter - spacer. it needs to be cut off far enough down so the emulator fully seats and fits flat on the adapter spacer. I think a nice even cut with a hack saw that is fully deburred will work fine.
Adjusting compression is a matter of adjusting the tension on the spring. I run mine at 3.5 - 4 turns down. you back the center screw out until the spring is loose, then wind it back until the spring is in contact with the emulator and the top washer under the head of the allen, then count the turns down. The fewer turns from contact the lighter the compression damping. Too much compression damping with cause the front to chatter as - after you hit a bump.
Rebound damping is controlled by bleed back holes in the damper. Rebound is adjusted but changing the weight of the fork oil, I use 15wt.
Once you have modified the damper rod it is only a matter of assembling the new setup.
SPRINGS:
This is an important part of the upgrade. I run between an 8.5KG and 9KG straight wound spring, I can't really tell much of a difference.
As far as setting pre-load, sag is an important indicator that you have the preload correct, Max at Traxxion dynamics gave me a rule that I have always followed for pre-load, a spring should never be compressed more than 20mm-3/4", if you need to compress it more than that you need to go to a stiffer spring. I run a 10mm spacer. PVC makes a fine spacer
I can understand that for street use a progressive spring will yield a more compliant ride at lower speeds, I'm not worried about that on the track as even the out-lap is at a good pace.
I have not modified any 76-78 400 forks, all of my stuff has been Daytona, RZ, FZ/FZR and R6. I will try and film doing a set, honestly, it can be done with a standard drill, a center punch, a couple of drill bits, and a saw if you are careful and pay attention to detail.
Thanks for that very in depth explanation! As it turns out, I just finished cutting and drilling the damping rods, and made some adapters (my first attempt at using a lathe). I'll be assembling the bike with the existing Eibach springs that were installed by the previous owner. They are no doubt old and need replacing, but I can change them easy enough later. I'd just like to get the bike rolling for now so I can move it around. The main thing was getting the rods done while I had forks apart for restoration. Thanks to everybody on this thread for chiming in with all the great insight. This forum rocks :metal:
Very nice work !
A few questions...
Since I have an adapter, I don't need to cut the pin correct? It clears with room to spare. Will it effect oil flow much if I leave it in there?
Also I've got one fork put together, but I'm not sure how to get the allen head bolt in the bottom of the fork tight without the damper rod spinning. I don't want to hit it with an impact driver (like I did to get it loose), for fear of breaking it off at the head or worse. I think the torque spec is 11 - 22 ft-lb.
I'm gonna go pick up some fork oil tomorrow, was thinking 10 wt to start? Manual says 144 ml (4.87 oz), but should I instead bring it up to a certain level above the cartridge emulator? I know a lot of this is gonna be trail and error, just looking for an educated guesstimate.
Quote from: JBeasty on February 14, 2023, 01:54:09 AM
A few questions...
Since I have an adapter, I don't need to cut the pin correct? It clears with room to spare. Will it effect oil flow much if I leave it in there?
Also I've got one fork put together, but I'm not sure how to get the allen head bolt in the bottom of the fork tight without the damper rod spinning. I don't want to hit it with an impact driver (like I did to get it loose), for fear of breaking it off at the head or worse. I think the torque spec is 11 - 22 ft-lb.
I'm gonna go pick up some fork oil tomorrow, was thinking 10 wt to start? Manual says 144 ml (4.87 oz), but should I instead bring it up to a certain level above the cartridge emulator? I know a lot of this is gonna be trail and error, just looking for an educated guesstimate.
with a 9KG spring 15 wt is what I use.
I made a tool for my Daytona damper rods, it is a T handle with a metric bolt welded to it, the top of the rod has a 12-point female "socket" the bolt engages.
You could make a tool that has a couple of pins sticking down that would engage the cross pin with a T handle at the top.
I have the spring on the Mike's emulator set at 2 turns and I've had 15 wt. oil in mine for several years and last year went to 20 wt.
15 wt it is then.
I could take a round or flat steel bar and cut a slot in it, good idea 👍
Do you guys put anything on the threads of that allen bolt to seal it, or is that copper/brass washer good enough?
putting stuff on the threads won't seal anything, the copper washer is plenty.
Done! 150ml 15w fork oil per leg, emulators set at 2 full rotations firm. Reduced spacer lengths to 32mm (actually just used PVC). This is here more to remind myself where I'm at when I get the bike running.