race tech gold emulator kit .part 2

now as some of you will remember i purchased said race tech gold emulator kit sometime ago now but due to work comitments have only just done it and ridden it .
here the low down.... after several conversation with various people with reguard to top out washer on or off ,the outcome come was it had to be on ... but i had a thought that being as the emulator was now doing the work what does the topout washer now do !! so i decided to machine the damper rod so i could fit another topout washer underneath it to stop it dropping and allowing the oil to go passed the emulator ...would it work or not !!
well after putting it all back together with 10mm of pre-load,500ml of 15wt oil in each fork leg and the yellow springs in on the emulator (instead of blue) off to the track we went ......
1st initial feel is the front end is a lot stiffer !! did think at first it was too stiff but after a quick ride around wow what a difference .
now i was gonna pull the emulator's out and adjust to see what difference it made but it was so dusty that i thought i would leave it for now and enjoy it . what i should do is pull the forks and try it with only one topout washer but i cant be arsed ..yet
so if your having problems with the front end ......and i'm sure you are ....get the emulator kit . now i'm no pro at this ,so if i can feel the difference then its got to be worth it .
no complicated questions now boys ....
(pictures are in old thread and will post new ones when i can find them)

Thanks. We need good info on the emulators. My own personal experience with the emulator is ZERO!! Never used one, so I'm not the guy to tell people how to set them up. And I can't chime in at this point as to whether you need that washer in there with the emulator. But it's very cool that you're looking into it and trying it out and letting us know. In the mean time...

In the stock fork, that washer is about the ONLY thing that contributes to having more rebound damping than compression damping. And it's not nearly enough. Probably the biggest fault with the stock fork is lack of rebound damping. If the emulators fix that, and by looking at how they're installed that seems to be one of their goals, then that's great news. Thanks again for the info.

l think this is what i will do rather than trying to reinvent the wheel with a new front end.

Thanks for the info.

sorry chaps been working away , the other thing i did do which i forgot to mention was i used genuine kawasaki fork seals .....shh dont tell anyone !! and so far (touch wood) they have held up better than the others i have tried and i only have one fitted in each fork not two !!!
kawasaki part number 92049-1251. among other things it fits the old z1000....
dont forget if you want to put two top out washers in place like mine you will have to machine a bit more out where the topout washer fits as there is not quite enough room. i made a special tool to hold the damper tube but thats only because i have a small lathe .
anymore more info please ask.
graham

this is the tool i made to fit the damper rod so i could machine the end to allow the emulator spacer to fit better . i also used it to machine a bit more of the gap where the topout washer fits so i could fit 2 topout washers.

next pic shows it in the lathe machining the top .

pic after machining (top part for emulator adaptor)

sorry but it looks like i forgot to take pics of the double topout washer assembly...oops

I also installed a set of the Race Tech Gold Valves a couple years back. At that time I had the chance to review the design of the Husky 40mm forks. One of the things that most don't realize is the top out washer in stock configuration is part of the damping circuit. It is a pressure operated bypass valve. It seals against the top of the damping rod during compression directing flow through the damping rod and opens on rebound for bypass. This is the reason the top out washer groove is 1.5 times the width of the top out washer and the top flange is wider than the slots in the top out washer. None of this matters once the damping rods are modified by drilling out the compression holes and the gold valve is installed to its carrier. I also left the top out washer in place. I welded the carrier to the damping rod and the carrier itself has a small groove cut to the circumference on height centerline that I installed a Teflon seal band to similar to the Ohlins shock piston band. I am using the stock springs cut 3" shorter with a PVC spacer (There are other dare I say better choices here, but thats what I did). I run Belray 15wt for oil set to limit hard bottoming and the Gold Valves are very close to where Race Tech said to set (Plus 1/4 turn).

Hope this helps,
Regards
PC

Taking this in order.
1. I have always been happy with the products and service I have received from Race Tech. I think you will be also if you are patient during the phone tag sessions.
2. I do not have any pictures of the modified damping rod, but will describe as best I can. I manage a corporate prototype shop in my day job so I have access to the machine shop. I turned the GV carrier from 6061. I left it oversize on the OD initially. It was pressed on to the damping rod and welded in two spots on the ID. (Where the damping rod holder tool would engage the top of the damping rod. These are the high points in the ID and it was easier to weld in those locations. You'll see when you assemble yours.) The welds are really only tacks at about 1/2" each. I then turned the final OD and cut the Teflon band groove.
3. I have access to some useful equipment and the spring force referenced here is from a Tinius Olsen force tester. It has a calibrated read out, but I should note that the accuracy range is +/- 1% of scale and in this case that is +/-5 pounds for the spring constant measurement.
The stock fork spring is 28" in length. It has a measured 500 lbs spring constant. That works out to be 17.85# per inch of travel with the 28" spring. If that seems really low, remember that the stock forks are designed to run air as the secondary spring.
My cut stock springs are 24" with a calculated spring force of 20.83 per inch of travel.
4. I am running a 4" PVC spacer with washers top and bottom to the PVC. I don't know how thick they are, but are not unusual.

5 Some other useful information from my notes and memory.
a. I weigh 185#
b. Stock spring measurements.
Wire Dia. = 178"
Spring outer Dia = 1.305"
Coil pitch: .535"
Total active length 28"

Regards,
PC

the pvc spacer or aluminium one as supplied with kit is used to set your pre-load setting. it will mean a lot more if you read the info about setting up the suspension from racetech . have tried to find on their website the info ,cant seem to find so i will scan said paperwork later , it will make a bit more sense .....

in think i understand what you have done ....basically you have created a new topout washer but on the side of the emulator spacer to prevent the oil going passed the damper tube !!
bit like what i did with putting two topout washers in the place of one to stop the topout washer working as it was designed to !!!
falcon shocks in the uk does something very similar to what you have done but he remakes the topout washer with holes in it . (pics to follow)
all the best
graham

There are no stupid questions.

1. The PVC spacer is used to fill the space in the fork tube when using a spring that is shorter than the available length. It is typically cut to provide .250" - .500" compression on the installed spring with the fork caps installed (Preload) and also sets the static sag. Most suggest .375" as a starting point.

2. Spring pitch should not effect overall suspension action assuming equal spring rates (lbs/inch or kg/mm). It is part of the spring design criterion. It is the distance between the spring coils. If all other factors were the same (Material, Wire diameter, Coil centerline diameter, Spring length) increasing the coil pitch will make a compression spring stiffer.

3. What set up is best?
The answer here is "It just depends". At 240 lbs, I do not think the stock spring can be made to work for you. Cutting 4 inches from the stock spring is approaching the available limit. It is possible to coil bind the spring if too much is removed and the more active coils removed from the stock spring the greater the strain placed on what remains. Most suspension type springs are rated in the 1 million cycle range for mean time between failure. How cycles many are left in a 30 year old spring? If you are already working with Race tech, they can provide a suitable spring. It will just cost more than free. Beyond that, the RT emulators were a good thing. Remember to get the rear suspension dialed in for your weight and riding also.

Regards,
PC

This is a good read. A bit over my head personally, but ya gotta start somewhere. I've just never delved into forks much back when I used to ride years ago. Would like to change that, and improve my level of understanding.

So, this is the hot ticket for the 40mm Husky legs huh. What does it bring these up to being equal to, roughly???? Much improved, but still not up with certain more modern forks, or ????

Again, nice read, thanks for posting.

Certainly not in the same catagory as modern, but WELL worth the money if you take your time and set them up properly. I set up a pair 4-5 years ago and it made a huge difference!
You also mention the hot ticket of the 40mm forks - they are good for any old style fork without a shim stack. They make varies sizes.

Question on cutting and squaring off fork springs:

Do you heat the cut section with oxy to flatten it? (then quench in oil?)
I imagine this does not help spring tension, but only affects the heated part of the spring?