Check out my stacks---Zerodog's fork mods

Discussion in 'Thumpers' started by Zerodog, Dec 26, 2006.

  1. Luke

    Luke GPoET&P

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    Hmm... so less float and more flex. I'll keep that in mind. I'm going to flog it this week in Death Valley, and then make changes based on how it does there. On the street it already feels like the front works better than the back.
    #21
  2. Zerodog

    Zerodog Long timer

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    Yes less float = more shim flex because the stack can't open as far. So on big fork movements, like braking the stack opens as far as it can on the spring until the shims start to flex. This is what keeps the bike higher in the stroke. I rode a nasty desert OHV area this weekend with ass deep sand whoops and very steep rocky hills. The front performed perfectly. I had enough adjustment in the compression to make the front resit bottoming on that stuff. The rear shock is close. I really pounded the crap out of it. For big whoops and trying to get it skimming I would need to add more shims to the compression side of the shock. But then you give up some small bump stuff on the road. On the mountain trails the shock was great. No kicking or bottoming. I think I will leave it alone for now. It seems to be a good compromise for what I am using the bike for. There are not many times when I am pounding whoops like I am on my real dirt bike. One option to make it better for this would be to add a thicker bottom out bumper.
    #22
  3. Luke

    Luke GPoET&P

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    So rule #1 of suspension modification is 'Change one thing at a time'. I broke that big time, but here are my impressions.
    Boney and I were riding in Death Valley last week. He was on a stock '02 640A, I had new front springs (+15mm length, .50kg/mm rate) with the new shim stacks listed earlier. My rear shock was stock.
    We traded bikes on a relatively clear dirt road. We rode high-speed roads, rock gardens, deep gravel roads, sand dunes and silty washes.

    The verdict: By far the biggest difference was from the change in steering geometry. I figure that there was a 1 degree difference in rake due to the change in ride height. My bike was much more stable (and slower steering). In the deep silt, Boney's bike was unstable to the point of being unrideable. Mine plowed a lot, but was stable.

    The suspension action was just as expected. Small rocks are now unnoticeable, and larger rocks don't upset the bike nearly as much. Brake dive is reduced significantly. On small jumps the bike feels very balanced on both takeoff and landing. No large jumps for me. I only bottomed out hard once, and it seemed reasonable given the terrain.

    I'm very happy with this suspension now. I think I'll leave the shims alone for now and work on the ride height- between the two bikes we have a boundry for very stable and unstable. Finding a good compromise should be pretty straightforward.
    #23
  4. bmwktmbill

    bmwktmbill Traveler

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    Z-dog,
    Hope the Baja was good.
    I got a couple of suspension questions.
    My '02 Adventure has the old style tap.
    I'd like to make them work.
    I measured the midvalve space carefully with the spring and shims out.
    It was 1.96mm.

    That makes me a little short on your complete midvalve. I don't want to space the nut out much more because it was peaned over as a safety measure to lock it in place. That seems like a good idea to me. The nut is right at the end of the threads with this measurements and tight.

    I was thinking I could substitute 1-24x.15 for 3-24x.1. Are they equivalent?
    That would leave me a float of 1.06 with the rest of your stack.
    My '02 midvalve would be:
    1-24x1.5
    1-22-.1
    1-18x.1
    1-14x.1
    1-10x.1
    1-12x.1
    1-14x.1
    1-20x.15

    So mv space is 1.96mm.
    Stack is .9mm
    Float is 1.05mm.
    What do you think?
    Should I order the updated spring for the '03 tap? It's cheap.

    BTW I unscrewed the taps to clean them. That was a bad job and needed heat to release the red threadlocker. After a good cleaning they work much more smoothly. The needles were hanging up in the bores.
    I am going to order new o-rings just in case the guy that was in there before me used a solvent that expanded them.

    Somewhere in my notes I have a shim substitution guide.
    Do you have it handy

    This is so fun,
    Bill.
    #24
  5. Luke

    Luke GPoET&P

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    Try here, the shim substitution guide is the third from the bottom of the list.

    According to this, 1 .15mm shim is equivilent to 3.4 .1mm shims.
    #25
  6. bmwktmbill

    bmwktmbill Traveler

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    Hey Luke,
    Thanks for the link.
    Now where to find a 24x.15 shim. Maybe MXtech
    Bill
    #26
  7. Zerodog

    Zerodog Long timer

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    I think that would work Ok. That is a lower float than what I am running now. My float is 1.13. The 03< midvalve spring might be a good thing or a bad thing with that midvalve. If it is lighter that could be good. Then it blows open easier on the small bumps. So it looks like you didn't need the 10mm shims on the back of the stack to get the float down. The 02 must have a longer shoulder than the 03. MX-Tech is a good bet for the shim you need. I will look tonight and see if I have some.
    #27
  8. alpiv

    alpiv Sr. nOOb

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    does anyone have the shock stack for the stock shock on an 03 Adv?
    #28
  9. bmwktmbill

    bmwktmbill Traveler

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    Thanks For looking/commenting on the stack Z dog.
    The 24x.15 is just a little heavier than three 24x.1. If I combine it with a little lower float and the soft mv spring it might be OK for the gravel especially because my bike is lowered and I don't have as much fork travel as the stock machines, the stiffer mid valve might be the right diagnosis especially if my fork springs are a little soft.

    I keep thinking PLUSH, whatever that means. Suspension tuners throw that word around.
    I want plush....
    Bill
    #29
  10. Zerodog

    Zerodog Long timer

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    I have them on my computer at home. I can post them for you when I get a chance.

    Bill, Keep in mind soft springs don't always mean plush. Soft springs will give a harsh ride if there is too much weight to support and the suspension blows through its stroke.
    #30
  11. alpiv

    alpiv Sr. nOOb

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    You rock
    #31
  12. bmwktmbill

    bmwktmbill Traveler

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    You're right.
    Bill
    #32
  13. Mulga

    Mulga Been here awhile

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    This has been a great thread so far and id like to bump it back to the top.:clap

    I have my front suspension apart at the moment to determin what shims I will need to buy. I like what Zerodog has done to his setup!:super

    I was wondering what other variations of setup spring/shim are out there other than the ones listed. It would be good to get some more data to help decide my setup and Im sure it will help others as well.:thumb

    I will also be installing .52 fork springs, a 8.4 or 8.6 rear spring as well as Infinity subtanks. I am currently a stable 230lb in gear :ricky

    Cheers

    Dan
    #33
  14. Mulga

    Mulga Been here awhile

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    Well I pulled apart my stacks. My bike is an 05 KTM 640 adv. For stock standard they vary from what others have listed particularly the Base and rebound.

    <table x:str="" style="border-collapse: collapse; width: 99px; height: 139px;" border="0" cellpadding="0" cellspacing="0"><col style="width: 90pt;" width="120"> <tbody><tr style="height: 12.75pt;" height="17"> <td class="xl22" style="height: 12.75pt; width: 90pt;" height="17" width="120">Base Valve</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">5 24 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">2 22 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">20 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">18 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">16 2</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">14 2</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">11 3</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">18 2.5</td> </tr> </tbody></table>
    <table x:str="" style="border-collapse: collapse; width: 90pt;" border="0" cellpadding="0" cellspacing="0" width="120"><col style="width: 90pt;" width="120"> <tbody><tr style="height: 12.75pt;" height="17"> <td class="xl24" style="height: 12.75pt; width: 90pt;" height="17" width="120">Midvalve</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl25" style="height: 12.75pt;" height="17">4 24 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl25" style="height: 12.75pt;" height="17">22 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl25" style="height: 12.75pt;" height="17">20 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td class="xl25" style="height: 12.75pt;" height="17">18 1</td> </tr> </tbody></table>
    <table x:str="" style="border-collapse: collapse; width: 90pt;" border="0" cellpadding="0" cellspacing="0" width="120"><col style="width: 90pt;" width="120"> <tbody><tr style="height: 12.75pt;" height="17"> <td class="xl24" style="height: 12.75pt; width: 90pt;" height="17" width="120">Rebound</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">5 Delta 24 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">20 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">18 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">2 11 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">14 1</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">10 3</td> </tr> <tr style="height: 12.75pt;" height="17"> <td style="height: 12.75pt;" height="17">16 3</td> </tr> </tbody></table>

    Sorry I forgot to get the stack and float measurements. I will get them off the other shock.
    #34
  15. bmwktmbill

    bmwktmbill Traveler

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    I thought those '05 stacks were interesting.
    Can you comment on how they handled the bumps.
    My guess is that the float is way too much and the fork really dives with heavy braking.

    I have around 3 K on Z-dogs stacks and I can vouche for a huge improvement on my '02 640a.
    I can also say that the big change was not so much springs as I stated elsewhere but due to the hydraulic changes.
    I did springs first and the results were disappointing. The hydraulic changes were huge.
    I have the same miles on his subtanks which I mostly run open.
    Its a cushy ride. Comfortable but controled.
    The bumps lose their sharp edges even with the tires over filled to assure maximum wear.

    This is just a great modification for the '02 fork.
    #35
  16. Zerodog

    Zerodog Long timer

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    Bill where are you now?? Are you on the other side of the planet yet??
    #36
  17. Mulga

    Mulga Been here awhile

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    You are right on all accounts and the float was around 2.5mm.
    #37
  18. Mulga

    Mulga Been here awhile

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    Thanks Rob,

    After reading this thread I decided to go ahead upgrade my suspension. Re-spring, new shim stack and Infinity Designs Sub-tanks. I contacted Rob (Zerodog) and got some really good advice on the setup I will need for my weight and style of riding. Also I digested as much information from previous threads here as I could get hold of.

    I wanted to be able to load up with gear for touring and not be handicaped for weekend blasts through the bush unloaded. Long distances of couragations (washboard for you yanks), washouts, potholes, bulldust, rocks and sand were concerns.

    So I pulled apart my front suspension to see what shims I needed. Doing this for the first time I did,t know what to expect. The internals of these WP forks are supprisingly 'simple' for want of a better word. I also found rust inside the piston rod. Goes to show you need to overhaul your forks periodically.

    I basically had to follow the same pattern shim stack Rob listed earlier in this thread but adding an extra Delta shim.

    Through Rob I ordered .52 fronts and a custom 8.6 rear spring (made by cannonracecraft) and Rob's sub-tanks. Rob really does a great job with his sub-tanks to add to that hes also generous with his time answering every one of my seemingly noobish questions.

    As well as selling his sub-tanks hes also thinking of stocking standard and custom springs for the 640.

    MX-Tech is where I ordered my shims. After a 6 week wait for backordered delta shims. They werent included in the package:huh anyhow gofigure. So the extra delta didn't make it to my stacks.

    Being 110kg (240lb) with riding gear the standard spring setup was horrible. Well now its whole new story. :clap:eek1:clapBloody fantastic. My initial experience on and off road is that the bike now feels more stable, corners better and dosen't dive on the brakes anywhere as much. On courgated dirt roads with the subtanks off it was fantastic compared to my old suspension. I said to my mate who was with me on his new KLR that I didnt think I needed to try the sub-tanks as the suspension felt great. However when I did try them :eek1 courgations what courgations! Rutts, sand rutts, potholes, washouts no problem. Even harpack dirt with pea gravel, actually felt like the Metzler Saharas holding, holy cow batman.I will still need to do some minor fine tuning of he compression and rebound settings.

    Its amazing what well set up suspension feels like. This is a must do.

    Thanks again Rob.

    Mulga:D
    #38
  19. LukasM

    LukasM Long timer

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    Hey guys,

    I was trying to finish assembling my forks with the shims and all the other good stuff that I got from Rob aka Zerodog. Suspension newbie that I am, I can't figure out at which end I start with the listed shims. :eek1

    My understanding, please correct me if I'm wrong:

    -For the base/compression valve holder:
    Start with 10x.3, go up to 24x.1, then the piston, check valve shim (24x.3) and finally the nut

    -Mid valve:
    Start mid valve with 10x.2, go up to 24x.1, then the piston

    -Rebound:
    This is what has me all confused as the order seems different. As far as I could see from pictures on KTMtalk and Husaberg.org the Delta shims go on first above the piston, and you end with a 16x.3 under the nut. Right or wrong?



    Thanks,
    Lukas
    #39
  20. Zerodog

    Zerodog Long timer

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    Mulga,

    Good to hear you finally got to make the changes to your bike. Glad you like it! Don't let your KLR buddy ride your bike. He won't give it back. He will just get on and never come back leaving your stranded with his KLR. Some KLR guys were eyeballing mine once.....

    Lukas,
    The shims go on just as they came off so to speak. The BV goes like this in very generalized terms. Refer to your PM or email from me for the order. It is all really important.

    BV/compression adjuster body.
    Backer shim or backer stack Stock is 18x.25
    Pivot shim 10x.3 or whatever you have
    Then the main stack. 12-14-16-18-20-24-crossover shim-multiple 24s
    Piston with counter bore facing up.
    Check plate
    spring
    Nut

    Basicly the shims resting directly on the piston are always the biggest ones. On the rebound the Delta shims are always first. Round shims will occlude the holes that go to the midvalve.
    #40