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  1. #1
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    Breaking and entering the damper circuit on a Fox air shock

    I searched a bit on self tinkering the oil section of a Fox rear air shock, but found little. Obviously, Fox does not want us to go anywhere near this. But as I trusted a guy and bought a used Stumpy FSR with a fully functioning RP 23, but ended up with a broken Specialized branded Fox Triad shock, I thought I might as well give it a go. Obviously, this will void any warranty and one might quite possibly damage something in the process. So beware.

    (EDITED aug15 with some new thoughts)

    Anyway, I thought I might as well document things with some pics:

    Here is the shock in "air sleeve service mode". Air sleve gone and air piston seal removed (it's easy to find info on hpw to get this far). I've also taken out the plastic goo from the nitro valve pellet retainer screw (bottom right). By carefully unscrewing the hex bolt (with my safety glasses on) and pumping the shock a bit I got rid of the nitro pressure.



    The lockout adjuster is easily removed by untightening this little hex bolt:


    Below you see the steel pin that at its bottom has the cam that control the three step lockout mechanism. The red rebound adjuster know can be removed after untightening the small hex bolt to the left, but I first removed the hex bolt just above the eyelet and cerefully removed the little spring and ball inside (which creates the clicks for the rebound adjuster). When working in this area, beware of the 1.5mm steel ball that sits bewteen the steel compression/lockout adjuster cam and the compression/lockout adjuster rod (which we will see later).



    Here is only the lockout adjuster pin. To remove it one might have to put a screwdriver into the hole and push away the rebound metering rod.


    The damper body unscrew fairly easily by just clamping one of the eyelets in a (soft) vice and using an adjustable wrench on the other eyelet (obviously with care taken). Here we are looking down into the damper body and can see the floating piston separating oil and nitro.


    Below you can see the valving assembly and the compression/lockout valve (the washer to the right). As you might see, even when fully closed some oil can float into one of the compression circuits by means of the four slots facing the side of the valve body (you see two in the pic)


    In the damper shaft you can now see the hole for the rebound circuit. The flow is metered by a hollow metering rod inside the damper shaft controlled by a cam on the red compression adjuster mechanism. In this pic, also note the washer below the valve body. This is a special little tricky compression valve, we'll see more of it later.


    The bottom of the valve body shows two set of holes. Four inner ones (which get a bit of oil flow even in lockout position) and 24 outer ones (which I guess is the high flow (speed) circuit. Both circuits are controlled by their own shim stacks as we will see.


    Here is the compression adjuster/lockout valving. The rod passes inside the hollow rebound metering rod and contacts the cam on the adjuster via a 1.5mm steel ball.
    Notice also the washer to the left of the valve body. Note that there is nothing but internal pressure (=nitro charge) and possible oil flow that pushes the lockout valve into its place. The adjuster cam only controls the minimum distance (three positions) to the valve body. The role of the little spring is still somewhat unclear to me. It contacts the (mounting bolt for the) valve body and lifts the lockout washer just short of 1mm away from the valve body (the big lockout washer can not move on its rod, rod + washer moves as one). It's unclear to me what happens in practice in the full lockout setting. if the shock takes a hit, the oil flow will surely push the lockout onto the valve body. But I'm not sure if the little spring is strong enough to keep the lockout slighty open "at idle", ie if the spring is strongern than forces from the nitro pressure.


    To remove the valve body I first removed the lockout assembly (the one above) and then made a special little tool to fit two of the holes in the body. I just drilled two 2.5mm holes in a piece of delrin plastic and used two drill bits as pins. At the other end, the square end of the air piston/ upper oil seal head can easily be clamped in a vice. But beware of the corner where the oil set screw is located...thin material around here, it seems)


    Now we see the whole valving assembly. It seems to have three compression circuits (+ rebound, which goes through the shaft). The bottom row are the shim stack for the 4-hole circuit. Small diameter shims means they are rather stiff, ie provide firm damping.
    The middle row of shims covers the 24 outer holes. This is the main circuit, I'd say. Large shims can bend away pretty far from the valve body and allow high flow if forces are high enough. The big shims goes towards the valve body. I suppose some tuning can be done by rearranging this stack, fx putting a smaller shim in between some of the big ones etc.

    An interesting note is that the first (4-hole) circuit is covered by the shims for the second (24 hole) circuit. So even when the first circuit opens, oil still has to push open also the shims for the second circuit. The last washer in the 4 hold circuit is also a stiffer one, effectively limiting the amount this circuit can open. So my guess is that this must be some sort of low speed circuit, maybe with the no 1 purpose of offering some "give" in the lockout setting.

    The upper row are the shims and special washer for the third circuit. We mentioned the special washer before. Oil flow for this circuit comes up though the damper shaft/valve retention bolt (upper right in pic below) and escapes into the special washer by means of some holes in the sides in the valve retention bolt (you can see on of these holes). The shims for this circtuit hence sits below the special washer, ie between the washer and valve body. Oil from the cavity in the washer bends the shims downwards, oil can flow down and then up around the washer. This flow is independent from the the circuits. With the main (24 hole) circuit seemingly being quite heavily damped (three big washers right at the bottom, then some smaller ones), a possible role of this circuit is to provide a subtle (lightly damped) flow at small hits before the main valve opens but then not seriously affect things at bigger hits (since the this valve circuit overall hardly can handle that much flow).


    Finally for now, Specialized sources special size of Fox shocks for many of their bikes. This Triad shock is 190*45 (7.5*1.75). How do they get away with this... Well by just using standard shocks and modify them, it seems. Below you can see an 5mm (aprox 0.25") travel reducing spacer. So it is really just your standard 190*50mm (7.5x2.0") unit. It should be possible to construct such a spacer that could be mounted without disassembly of the oil end of the damper (by having two thinner washers with a "slot" that could be pushed on the rode from the side, the rotated to lock them on the rod and then with a bolt or two securing them together).


    I'm still fighting getting the upper eyelet assembly off the shock shaft which is what I have to do to get the rebound metering rod out and replace its seals/orings (where the leak probably is since oil is coming out where the adjuster knobs are located.

    If anyone has some trick for getting the upper eyelet assembly and shock shaft apart (I have clamped the shaft in soft (wood) jaws and heated the upper assembly to loosen the red locktite inside, but still no luck.

    Comments welcome.
    Last edited by Ola H.; 05-12-2013 at 05:49 AM.

  2. #2
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    To unscrew the shaft without damaging it you can make a shaft clamp from a piece of aluminium or other soft metal.
    Drill a hole through as close as you can to the size of the shaft and then saw a slot through it. Use these in the vice to get enough grip without damage.

    Alternately, you can try wrapping a piece of inner tube around the shaft so it grips your wooden blocks better.
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  3. #3
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    Great info and pics. Thanks for sharing.

  4. #4
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    I'm going to post what's below and it will no doubt upset some, but it may save a lot more a bunch of money, frustration, and downtime.

    While it is nice to see information about this, and not even taking warranty stuff into the discussion, you have just opened up a Pandoras Box for a lot of people.

    I am all for seeing quality DIY maintenance, but having been a suspension geek for over 30 years, I know these are not your basic damper.

    By comparison, a motocross rear damper, any quality brand, Showa, KYB, Ohlins, are fairly straightforward to work on with no option circuits like Pro Pedal, or lockouts.

    These MTB dampers are more complex, much more difficult to properly bleed, and Fox has the infamous needle fill for the gas pressure.

    I have rebuilt and tuned loads of various MTB dampers. Removal of the center pin with the lockout plate secured to it was not such a good idea. The "O"ring at the opposite end, that is a fluid seal, normally is ejected when the pin is reinstalled.

    Yes you will need to remove the upper end fitting. Dougal is correct in stating an aluminum shaft block. Good luck with a wooden block, it has never worked well for me, plan on machining a true shaft block from aluminum. Also, fire up the propane torch and heat the fitting pretty good. While clamped very firmly, and don't let the shaft slip or it will be ruined, unscrew the end fitting. Obviously the heat will likely trash all the "O"rings, at least the urethane "O"ring will melt.

    I've done two dampers this week that required that much disassembly, both were RP series.

    I would rather rebuild 5 motocross dampers than one Fox Pro Pedal damper.

    BTW, you're only 25% done, reassembly and proper servicing is another entire book, not a chapter.

    BTW, anyone that has plans to pull apart an RP series with Pro Pedal, when you remove the piston assembly and shims, be very careful as you remove the piston retaining bolt. There is a spring for the Pro Pedal, under that spring is microscopic (about 1mm ID and 2mm OD) shims that add preload (PP threshold setting). Don't lose any of it or it won't work properly.

    Again, I'm all for folks doing their own work, but this is not for most.

    Great post and topic though, one I love to see and have no problem following.

    PK

  5. #5
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    Quote Originally Posted by PMK
    ...By comparison, a motocross rear damper, any quality brand, Showa, KYB, Ohlins, are fairly straightforward to work on with no option circuits like Pro Pedal, or lockouts...
    This fox propedal stuff looks more complicated than the WP PDS with a piston "and a half" and its associated complicated bleed process

    I wanted to mod the comp and rebound shim stack on an RP3 that I use on my daughters 24" FS bike to better dial it in for her very light weight but when I look at what's involved even I don't feel inclined to open it up - and there is nothing on a bike or motorbike that I have not fixed, rebuilt or re-engineered.

    Not wanting to derail the thread but are there any other manufacturer's shocks that are completely user serviceable?

  6. #6
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    Quote Originally Posted by PMK
    ...
    Removal of the center pin with the lockout plate secured to it was not such a good idea. The "O"ring at the opposite end, that is a fluid seal, normally is ejected when the pin is reinstalled.
    ...
    I see your point: not for most. But for me it's mostly a learning process. I just NEED to try now when the possibility opened up, so to say.

    About the o-rings. I figure one of these (lockout rod/rebound rod or rebound rod/damper shaft) is what is shot anyway, so they will need replacement, but thanks for the tip.

  7. #7
    PMK
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    Quote Originally Posted by TigWorld
    This fox propedal stuff looks more complicated than the WP PDS with a piston "and a half" and its associated complicated bleed process

    I wanted to mod the comp and rebound shim stack on an RP3 that I use on my daughters 24" FS bike to better dial it in for her very light weight but when I look at what's involved even I don't feel inclined to open it up - and there is nothing on a bike or motorbike that I have not fixed, rebuilt or re-engineered.

    Not wanting to derail the thread but are there any other manufacturer's shocks that are completely user serviceable?
    If you have been inside a WP PDS, we know they, meaning WP, botched it up by going a 2 piston design. The Ohlins and works WP are the 1 1/2 piston setups.

    Yes, this is more difficult to build, bleed, tune than a WP, and the results are not near as noticeable, with a downside failure being steep.

    Other manufacturers yes, or if you can fit it in her frame, buy the girl a Fox DHX 5.0 air. These are nice to work on and an easy service with some basic damper bleeding skills. Also, gas pressure is filled via the boost valve as they call it, and is shrader not needle.

    By the sound of it tigman, you know where to find me, send a PM and maybe your kid can get dialed in for a fraction of what PUSH charges. Never mind, noticed it was Sydney and I doubt that's anywhere but Oz.

    PK

  8. #8
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    PMK: Since I'm aslo in the market for a shock upgrade to the Triad (the one I'm experimenting with above) I'm wondering if a DHX air might fit a 06 stumpy. Maybe a bit overkill, but to me the possibility to work/tune the shock yourself is worth a lot.

    I see there is a 190mm (7.5") DHX air that one might hope could be reduced to 45mm/1.75" travel like Float series can. But will the piggyback fit? Of course, it will not fit the tunnel through the frame, but maybe it "ends" before it contacts the tunnel. I reckon I have about 110mm/4.2" from the upper eyelet, measured parallell to the shock, see image below.

    PMK or Anyone with a dhx air: is this enough? Other things to consider?


  9. #9
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    I believe I know PMK from KTMTalk and he is right about the RP series of Fox air shocks. They are amazingly complex and there seem to be endless variations of the propedal system over the years.

    As he mentioned the DHX Air is very easy, in comparison, to service. For a light rider it will work very well, but for a more aggressive or heavier rider the DHX Air is not as good as the RP23.
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  10. #10
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    Quote Originally Posted by Ola H.
    I see there is a 190mm (7.5") DHX air that one might hope could be reduced to 45mm/1.75" travel like Float series can. But will the piggyback fit? Of course, it will not fit the tunnel through the frame, but maybe it "ends" before it contacts the tunnel. I reckon I have about 110mm/4.2" from the upper eyelet, measured parallell to the shock, see image below.

    PMK or Anyone with a dhx air: is this enough? Other things to consider?
    I measure my 190x50 DHX5 as approximately 110mm from centre of eyelet to end of BO adjuster. On top of that the dust cap I have on the valve is another 5mm or so, but you could probably use a lower profile one than that if needed.

    Sorry I can't give exact figures at the moment as it's difficult to measure whilst bolted to the frame. Shout if you want more exact values. Looking at your picture though I'd be inclined to say it would fit.

  11. #11
    PMK
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    Ola
    I can not measure for you since one of my loaner shocks is, well being used as a loaner while I was working on a customers shock. His is done and waiting, but he needs swap back to his RP2 so I can get my loaner DHX 5.0 back.

    The loaner is a 7.5/2.0, so it's the one to check.

    Sorry, hope to get it back soon.

    PK

  12. #12
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    I have a DHX 5 coil on one of my bikes (also 7.5x2). Let me know if you're after anything specific.
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  13. #13
    PMK
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    Quote Originally Posted by Scott@GO-RIDE.com
    I believe I know PMK from KTMTalk and he is right about the RP series of Fox air shocks. They are amazingly complex and there seem to be endless variations of the propedal system over the years.

    As he mentioned the DHX Air is very easy, in comparison, to service. For a light rider it will work very well, but for a more aggressive or heavier rider the DHX Air is not as good as the RP23.
    Yes Scott, KTMTalk it is.

    Before I ask about the DHX vs RP, how is Zerodog doing? I have been trying to find time to see if he is interested in making some parts for me.

    So, back to the RP vs DHX. You mention DHX for light guys, is this based on the air spring volume or internal settings.

    I ask, because our Ventana ECDM tandem had an RP3 on it. The RP3 revalved was actually very good in PP#2, horrible in PP#1, and we never ride semi locked in PP#3. This is a small air can 7.875/2.0 RP3. I want to believe it was not a tandem damper on account of having to run the rebound fully closed on our first ride, fully closed on second ride after a fluid change, but mid clicks after a revalve. I noticed also our bike had an 8mm upper spacer set, where the short travel tandem has a 6mm spacer. After talking with Sherwood, he informed me the long travel bikes use 8mm. We bought the ECDM used with no mention of a shock swap, but who knows. Again revalved it's not bad.

    As for our DHX5.0 air, I got it from eBay, supposedly has only a few rides. I installed it and set up pressures and so forth. Had the wife make some clicker setting changes as we rode. This DHX has the large air can and was typical soft through the mid stroke on spring rate. I swapped it to a small air can, lowered the pressure setting to the same as the RP3, again a few clicker adjustments, and it dialed in very well with no revalve.

    So I ask, RP series vs DHX5.0 air, damping and internals or air spring setup?

    Also, do you have any Fox40 series used forks for sale? We need more fork in regards to tunability, not so much travel, since the fork is now the limiting factor on the ECDM. The limiting factor should be us.

    PK

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    Ouch, very tight then. Kind of steep money to take the chance. A more exact figure would for sure be welcome. I reckon even the schaeder valve with a (minimalistic) end cap would have to fit within the 110mm.

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    Quote Originally Posted by Ola H.
    Ouch, very tight then. Kind of steep money to take the chance. A more exact figure would for sure be welcome. I reckon even the schaeder valve with a (minimalistic) end cap would have to fit within the 110mm.
    Red = 108mm
    Yellow = 3mm
    Green = 6mm

    It'll look a bit off in the image as the camera distorts the angles;

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    Thanks. I'm gonna go home and measure the frame carefully again and start looking or the right sized DHX.

    PMK or someone else: do you reckon it's as straghtforward to limit travel on a dhx air as on a Float (ie that it can be done with a reducer on the shock shaft)?

  17. #17
    PMK
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    The DHX has a larger diameter shaft. The method of a spacer will work though..

    You might consider running that triad can so the spring rate is similar.

    How much you looking to spend, when my loaner is returned I'll likely part with it since it is to short to be a spare on the ECDM.

    PK

  18. #18
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    Quote Originally Posted by PMK
    Yes Scott, KTMTalk it is.

    Before I ask about the DHX vs RP, how is Zerodog doing? I have been trying to find time to see if he is interested in making some parts for me.

    So, back to the RP vs DHX. You mention DHX for light guys, is this based on the air spring volume or internal settings.

    I ask, because our Ventana ECDM tandem had an RP3 on it. The RP3 revalved was actually very good in PP#2, horrible in PP#1, and we never ride semi locked in PP#3. This is a small air can 7.875/2.0 RP3. I want to believe it was not a tandem damper on account of having to run the rebound fully closed on our first ride, fully closed on second ride after a fluid change, but mid clicks after a revalve. I noticed also our bike had an 8mm upper spacer set, where the short travel tandem has a 6mm spacer. After talking with Sherwood, he informed me the long travel bikes use 8mm. We bought the ECDM used with no mention of a shock swap, but who knows. Again revalved it's not bad.

    As for our DHX5.0 air, I got it from eBay, supposedly has only a few rides. I installed it and set up pressures and so forth. Had the wife make some clicker setting changes as we rode. This DHX has the large air can and was typical soft through the mid stroke on spring rate. I swapped it to a small air can, lowered the pressure setting to the same as the RP3, again a few clicker adjustments, and it dialed in very well with no revalve.

    So I ask, RP series vs DHX5.0 air, damping and internals or air spring setup?

    Also, do you have any Fox40 series used forks for sale? We need more fork in regards to tunability, not so much travel, since the fork is now the limiting factor on the ECDM. The limiting factor should be us.

    PK
    PK,

    Zerodog is doing great. We hang out about once a week and work on MTB projects when we have time. Not sure if he is making parts on the side because his full-time job is keeping him busy. He's also been riding a lot of motorcycle trials. Not sure if those things even have damping.

    I can't begin to compare shocks on tandems as I don't own one and don't think I've ever even ridden one. However, on singles I do have loads of experience and testing. The DHX Air has problems in both areas you mentioned. Everyone I've ever seen comes with a large air sleeve and requires very high air pressures (generally 250psi or more) for riders over 150 - 170 lbs. Yes, if you get a small air sleeve and combine it with a low leverage bike like the Ventana you can make it work.

    For comfort on a tandem I bet it would be good as they have very little compression damping. However, when used as intended on a 5 - 7" travel (single) bike they just can't keep up as the the speed picks up and the terrain gets rough. I believe that this is mostly due to the damping oil being pressed through the rebound rod to get to the reservoir. My guess is they just start cavitating and loose most of their damping.

    Sorry, no used 40s at this time. I'd be concerned with the lack of steering radius you would get from a double crown fork on a super long wheelbase bike.
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  19. #19
    PMK
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    Quote Originally Posted by Scott@GO-RIDE.com
    PK,

    Zerodog is doing great. We hang out about once a week and work on MTB projects when we have time. Not sure if he is making parts on the side because his full-time job is keeping him busy. He's also been riding a lot of motorcycle trials. Not sure if those things even have damping.

    I can't begin to compare shocks on tandems as I don't own one and don't think I've ever even ridden one. However, on singles I do have loads of experience and testing. The DHX Air has problems in both areas you mentioned. Everyone I've ever seen comes with a large air sleeve and requires very high air pressures (generally 250psi or more) for riders over 150 - 170 lbs. Yes, if you get a small air sleeve and combine it with a low leverage bike like the Ventana you can make it work.

    For comfort on a tandem I bet it would be good as they have very little compression damping. However, when used as intended on a 5 - 7" travel (single) bike they just can't keep up as the the speed picks up and the terrain gets rough. I believe that this is mostly due to the damping oil being pressed through the rebound rod to get to the reservoir. My guess is they just start cavitating and loose most of their damping.

    Sorry, no used 40s at this time. I'd be concerned with the lack of steering radius you would get from a double crown fork on a super long wheelbase bike.

    Yes, we found also the need to run what I thought was to much air spring pressure with the large can. In regards to compression damping, we had to back off PP with the high pressure and wallowed or blew through the stroke. Small can cured this.

    Yes, our ECDM is 2:1, which helps in many ways, but should overtax the compression circuit. The 2:1 did let us dial in a very detailed PP setting between detents.

    On the single bike, my guess is that it is not so much a flow into the rezzy on account of the fluid travelling the tube, rather once again platform settings and more importantly, flow restrictions of the PP circuit add unwanted compression spikes. If the damper is cavitating, and it may be, it would be in rebound, thus affecting compression also.

    Have you or anyone removed the platform circuits and built a DHX air as a conventional based damper? This would probably make it decent. Then again, for DH, a coil over setup, with direct flow from body to rezzy is better than shaft flow.

    We already run double crown forks with an ATC. Sadly the damping is not up to the task but may be if I work the cartridge. I'm leaning towards a Kashima Fox40 for the ECDM if I need to buy something new.

    PK

  20. #20
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    Great write up and pics Ola H. Thanks for taking the time to post this info up. It's enlightening.

    P

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    Ola, or anyone, how does the gas charge hold pressure before the cap is replaced?

    Is it charged with a needle similar to the old Vanilla RC?

    Thanks for the pics and interesting discussion.

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    Float series shocks are charged with a needle through a rubber disc at the top of the shock body. The shock is charged after its all assembled and bled. Triads are similar.

  23. #23
    PMK
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    Quote Originally Posted by Ola H.
    This photo shows the gas service port which is a rubber disc, pierced by a needle, located under the set screw on the dampers lower end, next to the mounting eye. The set screw is drilled in the center for needle access. Normally when you look at these they have a plastic plug to minimize tampering.

    The disc setup is somewhat of a nuisance. It's a shame I can't get warranty replacements on needles like tools at Sears.

    The person that posted about servicing the gas after assembly and bleeding is correct. Also, I have never seen it posted, but the depth of the floating piston is critical on initial build and final bleed. To deep and the damper hydraulic locks, to shallow and the damping piston contacts the IFP and cavitates the damper and rides the combined spring and gas pressure with no damping.

    They can be serviced with a few special tools and some knowledge. Just be careful not to do more harm than good.

    PK

  24. #24
    PMK
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    Ola, you might offer these guys that are itchin' to bust into their dampers a shot of the fluid bleed port. This is the small set screw that uses a ball to seal a drilled hole in the sealhead.

    PK

  25. #25
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    Quote Originally Posted by PMK
    Also, I have never seen it posted, but the depth of the floating piston is critical on initial build and final bleed. To deep and the damper hydraulic locks, to shallow and the damping piston contacts the IFP and cavitates the damper and rides the combined spring and gas pressure with no damping.
    Yes I've given Ola some useful information on setting IFP depths.
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    VERY interesting. I'll PM you about it.

  27. #27
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    Dougal and Ola, going to PM's now is kind of unfair to this entire topic.

    I still support the idea that this is more than most should even consider, but it seems wrong to just "leave em hangin" if they are willing to try.

    PK

  28. #28
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    Quote Originally Posted by PMK
    Dougal and Ola, going to PM's now is kind of unfair to this entire topic.

    I still support the idea that this is more than most should even consider, but it seems wrong to just "leave em hangin" if they are willing to try.

    PK
    Not to worry, that's not the intention.
    The good thing for people watching is that the main body of this shock is just like your average float. So anyone wanting to do a basic oil change etc can use this info too.

    I've always set my IFP depth by feel. Put it together, see how it feels by hand and give it a little more or little less. But the official depth for this one is about 55mm down from the top.

    I've got a 7.5x2 RP3 here on my desk. But it belongs to a mate who's curently out of the country so I shouldn't pull it apart until he's okay with that.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
    www.dougal.co.nz Suspension setup & tuning.
    SPV Devolve

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    I can get some picks of a Pushed RP3 later today if you'd like. It's a bit different than the triad. There are no compression shims, I used them in my short shocked Swinger, but you can still get an idea on how it works.

  30. #30
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    Quote Originally Posted by Scotth72
    I can get some picks of a Pushed RP3 later today if you'd like. It's a bit different than the triad. There are no compression shims, I used them in my short shocked Swinger, but you can still get an idea on how it works.
    Would love to see that

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    Cool thread. It's nice to see the inside. However, if my RP23 ever needs more than the air can maint, it's going ot Fox. They are only 30 mi from me anyway.

    I may have my fun pulling apart my lefty and such. It too has it's "ways" that you have to do things. It just seems more straight forward than this.
    Lead by my Lefty............... right down the trail, no brakes.

  32. #32
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    I'm just trying to make sense of the piston porting, but is appears to me that the 4 larger holes are the high speed compression ports of on the piston, and they probably are completely covered by a high speed shim stack on the reverse side. The 24 smaller holes are likely for high speed rebound which is also shimmed. The low speed rebound is the adjustable orifice in the rod.

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    Here are the pics I promised.











    This is an older RP3, 2005ish. It had a preloaded high speed comp stack. but like I said, that is now in another shock.

  34. #34
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    Scott, that seems like an odd design, it appears the since the shims are installed on a secondary piston with edge seals that a significant amount of oil would bypass the shim stack. Do the black washers completely block the compression ports?

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    The valves on the end are check valves for the low speed damping circuits. The oil travels each way through the passages in the square sided bolt, and then out through the check valves, which also provide damping. Compression is through the propedal valve located at the front of the piston bolt. The pp lever provides spring preload to that valve. The rebound travels from the hole in the shaft, through the rebound needle orifice, and out the check valve.
    High speed damping is on the main piston itself, shims on both sides. There is quite alot going on inside this shock, took me a while to get my head around it.
    You can see there is quite a big difference in the aftermarket piston. Ports are way bigger, allowing more oil flow.

    The big black washer you see is one of the high speed comp shims. There were 3 of them total, and were set up with some preload.

  36. #36
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    Quote Originally Posted by PMK
    Dougal and Ola, going to PM's now is kind of unfair to this entire topic.

    I still support the idea that this is more than most should even consider, but it seems wrong to just "leave em hangin" if they are willing to try.

    PK
    No worries. I'll post up what happens once I get the time to do it. I'm having a friend make some aluminum blocks for the shock shaft as we speak. Tried with various types of wood, but like you said, it didn't work.

    Then it's a matter of finding the correct o-rings, but as my neighbor is an o-ring professional, I have my hopes up.

  37. #37
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    Quote Originally Posted by joshdurston
    I'm just trying to make sense of the piston porting, but is appears to me that the 4 larger holes are the high speed compression ports of on the piston, and they probably are completely covered by a high speed shim stack on the reverse side. The 24 smaller holes are likely for high speed rebound which is also shimmed. The low speed rebound is the adjustable orifice in the rod.
    I don't think that is it. Rebound is all through the shaft, it seems. No high speed circuit. Both 24 hole + 4 hole + the extra "upside down" circuit appear to be compression. They are all totally closed on rebound. The 4 hole may serve some high speed compression, but the way the holes allow slight flow also in lockout mode tells me that circuit also serves as some kind of "safe gate".

  38. #38
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    Quote Originally Posted by Scotth72
    Here are the pics I promised.
    Obviously a more advande valving than o my triad, with fx a real shim stack rebound.

    I think I get most of it, but ca you tell me the little spring loaded pp pin goes and what kind of flow it allows/restricts.

  39. #39
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    You can see it closing the hole in the piston bolt in the 2nd picture. It's spring loaded, and the spring preload is determined by a cam turned by the pp lever. When the pp lever is open, oil has and easier time getting through the center of the piston bolt, and out through the rear check valve. When pp is on, more oil is forced to go through the main shim stack.

    You can't see it to well in the picture, but the piston bolt has a square cross section, with holes drilled through its center line, and then holes drilled across it, one just below the hex head, and one by the threads. That is where the low speed oil flows. On compression, its through the center hole, around the pp valve, and out through the hole near the threads. On rebound, its through the hole in the main shaft, around the rebound needle, and out the hole near the hex head. The hollowed out sections on the check valve plates (look like a Y), line up with the holes on the piston bolt, allowing flow. The check valve shims make the oil go out the correct hole when the shock cycles.

  40. #40
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    would it be possible to mount a Float style piston assembly into the triad damper? You wouldn't be able to adjust the propedal or lockout but could you just fix the prodedal to level 1?

  41. #41
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    Scott, if you lay out the pistons, valve plates, and shims in a simpler way so those looking could better see the assembly sequence it will make more sense.

    4 Stacks of shims, on the compression side, the clamp is shared by both stacks, on the rebound side, two independent stacks.

    PK

  42. #42
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    Quote Originally Posted by joshdurston
    would it be possible to mount a Float style piston assembly into the triad damper? You wouldn't be able to adjust the propedal or lockout but could you just fix the prodedal to level 1?

    First off why?

    Second, you would have problems if you left the propedal valve installed, you would have shimmed only rebound with no rebound clicker function...I think...no freebleed circuit would exist.

    When built as a PP, keeping it simple, there are 4 stacks, compression, rebound, PP compression, PP rebound. Lose one or valve it to firm and the damper may not extend, or you may get true lockout.

    If you are revalving, give very careful thought to the clamp diameters AND total shim accumulated thickness, adding or removing will alter the PP valve preload.

    This is not an easy to understand damper, and even more difficult to know what changes to make in valving.

    BTW, it doesn't appear PUSH enlarged the ports, just modded the lip clearance. An important mod for a non PP damper, or for running non PP settings, but overall, I'd be curious to see the damping change on a big dyno, capable of 100IPS minimum or if PUSH even made the leverage adapter to test effectively on their small dyno.

    PK

  43. #43
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    Quote Originally Posted by Scotth72
    The valves on the end are check valves for the low speed damping circuits. The oil travels each way through the passages in the square sided bolt, and then out through the check valves, which also provide damping. Compression is through the propedal valve located at the front of the piston bolt. The pp lever provides spring preload to that valve. The rebound travels from the hole in the shaft, through the rebound needle orifice, and out the check valve.
    High speed damping is on the main piston itself, shims on both sides. There is quite alot going on inside this shock, took me a while to get my head around it.
    You can see there is quite a big difference in the aftermarket piston. Ports are way bigger, allowing more oil flow.

    The big black washer you see is one of the high speed comp shims. There were 3 of them total, and were set up with some preload.
    Scott
    I believe the high and low speed stacks are labeled incorrectly. The low speed ones will normally see the easiest deflections and large port areas / greater radius from the shim 0.0, plus have low deflections. These stacks will also flex more during HS movements, but in this case, the deflections are limited by stop plates of some type. Therefore the HS flow must be taken via the stacks adjacent to the shafts end and under the bolts head.

    PK

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    Here is a diagram:


  45. #45
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    The small size of the orifices would make these the low speed ports. The oil cannot move throught them at a high rate of speed. The big ports in the main piston are for large volumes of oil movement, high speed hits.

  46. #46
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    Quote Originally Posted by Scotth72
    The small size of the orifices would make these the low speed ports. The oil cannot move throught them at a high rate of speed. The big ports in the main piston are for large volumes of oil movement, high speed hits.

    And which diameter shims are normally responsible for low speed control. HS movements are combined flows of both stacks.

    I don't agree with you, but will let your words / post dictate.

    PK

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    The little shims you see are pretty much check valves. They flex very easily, allowing oil to pass without hindrance in one direction only. The oil flow is controlled with the rebound needle and the pp valve. The holes are so small, a high speed impact will spike. Only so much oil can flow such a small hole at one time. The oil will then be forced to go through the shims and ports of the main piston. There is a shim stack on both sides of the piston, separate from the smaller shims/check valves you see in the pic. I'm not sure my pics show this clearly enough.

    Anyway, I just wanted to provide some pics and diagrams to those interested. Hope they helped.

  48. #48
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    BTW, it doesn't appear PUSH enlarged the ports, just modded the lip clearance. An important mod for a non PP damper, or for running non PP settings, but overall, I'd be curious to see the damping change on a big dyno, capable of 100IPS minimum or if PUSH even made the leverage adapter to test effectively on their small dyno.
    I wish I better understood your distaste for my company. It appears that you are involved in Moto, the industry I worked in before starting PUSH, so you understand that tuning companies such as mine are widespread. You belittle our "small dyno" without even knowing the specification, but we're the only MTB suspension tuner that is serious enough to have one. Just a bummer I guess, for not only me, but the people that work so hard here at PUSH.

    Darren

  49. #49
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    So Darren, am I correct in my understanding of the way oil flows through this damper? If not, could you enlighten us please?

  50. #50
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    So Darren, am I correct in my understanding of the way oil flows through this damper? If not, could you enlighten us please?
    Seems like you've got the jest of it. In basics: Low Speed compression and rebound is handled through the check plates(triangular shaped washers) which are fed by the subsequent holes in the piston bolt. The spring loaded poppet valve feeds the compression into the bolt and is adjusted by the external PP lever, while the rebound is fed by the bleed hole in the shaft under the piston which is being metered my turning the rebound dial.The system must be checked with no free bleed in order to build up the compression threshold(ProPedal effect). High Speed damping is controlled by the valving stacks on each side of the main piston face.

    There are several other factors which I have to keep proprietary in nature that can also change the way the system feeds oil and therefore changes the damping force curve.

    Darren

  51. #51
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    Guys, I'll send Darren a PM to keep this post track straight.

    Scott, the checkvalves are not so much for low speed damping as they are to make the PP effective. The entire damper is a series of balanced circuits. With PP off, this negates for the most part the spring and micro spacer shims that preload the pop off valve. Selecting PP #2, will increase low speed damping noticeably. This indicates that the pop off spring is critical in rate and preload. With PP in full effect, yes the fluid is routed across the shims on the piston face, but also the flow could unseat the pop off valve if severe enough.

    There is a lot more going on than just the triangle valves and soft stack being the low speed. In my opinion, if you work the triangle valve shim stack to tune LS compression you may find the port area to small to give sufficient shim seat pressures and still remain controlled.

    You might find that changing the main piston shims to different aspect ratio of the stack to be more versatile in all phases.

    Ironically, often large ports are affiliated with HS damping, while ports to small can spike a damper, it is really flow volume over time. Additionally, the stack design, be it linear, preloaded, or digressive plays into this also.

    http://www.penskeshocks.com/files/TS...leedPiston.pdf

    When I have time I'll take some photos.

    PK

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    Thanks Darren.

    PMK, I get what you are saying. I think we were just saying it differently. I never stated that shimming the check valves was a valid way of drastically changing the damping. Just that it may have some effect.

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    Quote Originally Posted by PMK
    How much you looking to spend, when my loaner is returned I'll likely part with it since it is to short to be a spare on the ECDM.

    PK
    PM me when you get it back and we can discuss it. I'm very interested in getting such a shock for a reasonable price.

  54. #54
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    Quote Originally Posted by Ola H.
    PM me when you get it back and we can discuss it. I'm very interested in getting such a shock for a reasonable price.
    I was hoping to have it already.

    PK

  55. #55
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    Have any of you ever heard of anybody removing the nitro valve pellet retainer screw and putting in a valve stem to adjust the compression? I've heard the old float's valve stem threads in. Would this do anything?
    My rp23 hv with boost valve has no platform that is noticeable and I'm told it has something to do with this.

  56. #56
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    Quote Originally Posted by taletotell
    Have any of you ever heard of anybody removing the nitro valve pellet retainer screw and putting in a valve stem to adjust the compression? I've heard the old float's valve stem threads in. Would this do anything?
    My rp23 hv with boost valve has no platform that is noticeable and I'm told it has something to do with this.
    I did this on an old school fox RC with the piggyback, but I had to buy a special tap (5/16-32 I think). I had to use a fox schrader valve from an old destroyed float. I searched high and low for "non fox" schrader valves with suitable threads, but never had any luck. I've re-valved my RP-23 a couple times. I rigged a syringe from a gas chromatograph needle onto a shock pump that works really well. It's not all nitrogen, but I figure if plain air is good enough for a DHX, it will work for a RP23.


  57. #57
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    Quote Originally Posted by taletotell
    Have any of you ever heard of anybody removing the nitro valve pellet retainer screw and putting in a valve stem to adjust the compression? I've heard the old float's valve stem threads in. Would this do anything?
    My rp23 hv with boost valve has no platform that is noticeable and I'm told it has something to do with this.

    It can be done but is a huge pain.

    From experience I know the internal pressure has a small window of decent performance. Additionally, every change is a compromise on some other parameter.

    Pull the air sleeve. Compress the shock, does it extend on its own. Keeping the shock so the rod is upright and at the top, does it extend smoothly on 6 or so consecutive cycles. If it bumps near full extension, the internals have air that should not be in there.

    Send it in for a rebuild, or follow this topic.

    PK

  58. #58
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    It's a new rp23, less than 20 hrs on it probably. I sent it in anyway, but I am doubtful whether fox will do much. I think I'd need to have it pushed to my specific params. Maybe I should just look for a dhx air.

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    removing the shaft



    As we can see on the picture above, there is a tread at the top of the shock shaft. I believe that the shaft can be remove by using a thick rubber surrounding the shaft and turn it with a clamp.

  60. #60
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    Quote Originally Posted by Ola H.
    ...I thought I might as well give it a go

    So after a long winter filled with other things, I''ve started to work on this again. I managed to get the "upper head" unscrewed with the help of lots and lots of heat and some clamps a friend made. My neighbor helped me find replacement for each o-ring in the shock. Quite a bit of work and he's in the business. I replaced all o-rings and made a needle adaptor for my shock pump as well as a hex tool with a hole in it. However, I have not managed to pump it up and remove the needle without too much air escaping. I seem the rubber pellet is a bit damaged and my neighbor is looking for a replacement.

    However, I can pump the shock up and cycle it with the needle/pump attached. At first, it seems to work, but then you can see the tension go away from the lockout lever and a few strokes later the shock again starts to leak from the adjustment knob area. I reckon what happens is that the lockout rod inside the rebound rod is not pushed in hard enough by the air air pressure (aka nitro). So eventually, it slips out a bit and oil can flow past the o-ring. I reckon this was exactly the original problem too, rather than that the oring for the lockout rod was blown. When I got the shock, the lockout lever already had that sloppy feel, indicating that the lockout mechanism was not tensioned enough by the internal pressure of the shock. So in some sense, I'm on square one.

    I'm thinking of just plugging the rebound rod and not use the lockout since I don't like that anyway. I'll let you know.

  61. #61
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    Quote Originally Posted by Ola H.
    So after a long winter filled with other things, I''ve started to work on this again. I managed to get the "upper head" unscrewed with the help of lots and lots of heat and some clamps a friend made. My neighbor helped me find replacement for each o-ring in the shock. Quite a bit of work and he's in the business. I replaced all o-rings and made a needle adaptor for my shock pump as well as a hex tool with a hole in it. However, I have not managed to pump it up and remove the needle without too much air escaping. I seem the rubber pellet is a bit damaged and my neighbor is looking for a replacement.

    However, I can pump the shock up and cycle it with the needle/pump attached. At first, it seems to work, but then you can see the tension go away from the lockout lever and a few strokes later the shock again starts to leak from the adjustment knob area. I reckon what happens is that the lockout rod inside the rebound rod is not pushed in hard enough by the air air pressure (aka nitro). So eventually, it slips out a bit and oil can flow past the o-ring. I reckon this was exactly the original problem too, rather than that the oring for the lockout rod was blown. When I got the shock, the lockout lever already had that sloppy feel, indicating that the lockout mechanism was not tensioned enough by the internal pressure of the shock. So in some sense, I'm on square one.

    I'm thinking of just plugging the rebound rod and not use the lockout since I don't like that anyway. I'll let you know.
    Forgot to mention in my previous post. I dremeled a slot in a hex wrench to pass the shock needle into the septa with the wrench installed. This allows you to tighten the septa around the needle to prevent pressure from escaping during pressurizing the shock. you can still slide the needle out "with a little friction" without loosing any air. Then give the hex screw another half turn to permanently seal the IFP chamber.

    Hope this helps.

  62. #62
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    Quote Originally Posted by LAKESNAKE
    Forgot to mention in my previous post. I dremeled a slot in a hex wrench to pass the shock needle into the septa with the wrench installed. This allows you to tighten the septa around the needle to prevent pressure from escaping during pressurizing the shock. you can still slide the needle out "with a little friction" without loosing any air. Then give the hex screw another half turn to permanently seal the IFP chamber.

    Hope this helps.
    Yeah, I tried that but I think the little rubber pellet simply needs to be replaced since even with that trick pressure still escaped when taking the needle out.

  63. #63
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    Updates?

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    I don't remember what my last update was, but I managed to find all o-rings and stuff and get the shock back together but the lockout (inner) rod still didn't seem to run OK. Possible it was me not being able to get the pressure in the shock up high enough, but after a few pumps of the shock, it started to leak oil from the adjuster again and the obvious reason was that the lockout rod kind of crept out fro its position.

    Since I wasn't gonna use the lockout anyway I simply plugged the damper rod an put together the shock without the lockout option (ie without the lockout rod). Now it seems to work but I've yet to put it on the bike since I bought another frame in in the mean time and don't have part to put the original Specialized back together. But the intention is to do it one day or the other and I'll report back. I'll try to post some pics of my syringe setup for pressurizing too.

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    OK, time for one more update. As mentioned earlier, I got another very nice frame so fixing this shock has not been a priority. But the other day I found some inspiration and built the good old Specialized up. As also mentioned, I had some problems getting the lockout mechanism leak free so I simply removed it and plugged the rebound shaft. Obviously, the right amount (=huge amount) of nitro (or air) pressure is very important for the lockout/platform mechanism to work and I in fact think that the problem from the very beginning was too little pressure here rather then a faulty o-ring.

    But anyway, while inside the damper I also shifter around some washers, placing one of the smaller ones between the first big ones. And with the bike put back together, the suspension now works very, very well. I didn''t get to ride it much in the original setup, but from what I remember the new tune is much more nice and active. I recon removing the lockout mechanism also allows more more undisturbed flow overall, ie even compared to then the lockout was in open mode.

    With my home made needle adaptor, I only manage to get around 80-100psi in the nitro chamber, but that seems to be enough, at least I have not experience problems so far. But I'm gonna test it on a really hard trail tomorrow, and we'll see.

  66. #66
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    So you've made it into a multistage shim stack?

    I look forward to your test results. If the nitrogen pressure isn't enough then the shock will suck air in on fast hits. The float on my wife's bike does this even with 300psi. Perhaps it's time to invest in some N2 regulators.
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
    www.dougal.co.nz Suspension setup & tuning.
    SPV Devolve

  67. #67
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    Quote Originally Posted by Dougal View Post
    So you've made it into a multistage shim stack?

    I look forward to your test results. If the nitrogen pressure isn't enough then the shock will suck air in on fast hits. The float on my wife's bike does this even with 300psi. Perhaps it's time to invest in some N2 regulators.
    Yeah, kind of multistage:ish, I reckon. In any case it worked remarkably well today. No leaks and no hissing sounds from air in the shock, not even after the pretty demanding ride (demanding on the shock). I now have a super smooth feel from the back end. 25-30% sag at 160 psi, super active with around 50% travel getting used even through some fine roots - providing a very cloud like feel. Then a smooth transition into maybe 80-90% of the travel which I get regularly when riding though rougher stuff. Finally each section of the trail I rode seemed to have one or a few hits that pretty much gave me full travel, but I still didn't feel any harsh bottom outs. Overall just very, very smooth, with no spikes either on sharp hits or more rolling stuff. The rebound adjuster works very well too with a range from mega fast to almost not moving back out at all.

    I don't have much to compare with, but for what it's worth, the suspension action now complements the bike perfectly for the type of trails I ride.

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    Quote Originally Posted by Ola H. View Post
    OK, time for one more update. As mentioned earlier, I got another very nice frame so fixing this shock has not been a priority. But the other day I found some inspiration and built the good old Specialized up. As also mentioned, I had some problems getting the lockout mechanism leak free so I simply removed it and plugged the rebound shaft. Obviously, the right amount (=huge amount) of nitro (or air) pressure is very important for the lockout/platform mechanism to work and I in fact think that the problem from the very beginning was too little pressure here rather then a faulty o-ring.

    But anyway, while inside the damper I also shifter around some washers, placing one of the smaller ones between the first big ones. And with the bike put back together, the suspension now works very, very well. I didn''t get to ride it much in the original setup, but from what I remember the new tune is much more nice and active. I recon removing the lockout mechanism also allows more more undisturbed flow overall, ie even compared to then the lockout was in open mode.

    With my home made needle adaptor, I only manage to get around 80-100psi in the nitro chamber, but that seems to be enough, at least I have not experience problems so far. But I'm gonna test it on a really hard trail tomorrow, and we'll see.
    Hi there, great thread!

    I have a faulty rp2 that seems to have no rebound and no lockout at all, keeps air pressure correctly though.
    Me too, have found oil leaking around the rebound knob and diagnosticated a faulty o-ring but since I read that it could simply be a matter of the lockout rod moving by means of low or no n2 pressure, and maybe this low or no pressure is keeping oil away from the damping piston?
    I´m wondering if adding pressure to that ifp chamber could fix the problem?
    could it be that easy?
    maybe just pump it up?
    I read that you use a needle valve to pump air through the round disc below that allen screw at the bottom of the shock, and seems some of you have tried to put a schraeder valve there. how much pressure?
    maybe a picture of this rubber disc and allen screw undone? it is difficult for me to imagine how to charge the shock...
    BTW how much oil and sae does this shock run in 200 x 50 lenght and stroke?
    thanks guys I really appreciate the effort behind all this thread!

  69. #69
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    Hi Ola H.
    since I can not Pm I´ll try and contact you here.

    first thanks ALL of you for your thread, is very interesting.
    I seem to have a problem with my rp2 that you´re familiar with. leaking oil through the rebound knob and no lockout or rebound regulation.
    could it be just a matter pumping air into ifp?
    I just miss the part of replacing those o-rings in your thread to give you an applause ha ha ha
    do you think its a must to replace these o-rings or any other simpler solution?

  70. #70
    moaaar shimz
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    If you lost some oil it's time for a full rebuild. No simpler solution.

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    so that brings the second question up:
    how much and sae oil? heard its sae 10 but dont know how many cc´s or oil height ofr a 7,875 x 2 rp2
    thanks for your quick reply tacubaya gracias señor

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    Shock is dissasembled. Just need to take apart the shaft to replace those hidden o rings. Need help with ifp depth and pressure and oil quantity and sae. Dont want to build a hidraulic pump hahaha.
    Btw will try to replace that stupid rubber disc with a schraeder valve.

  73. #73
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    Quote Originally Posted by Scotth72 View Post
    Here are the pics I promised.











    This is an older RP3, 2005ish. It had a preloaded high speed comp stack. but like I said, that is now in another shock.
    in the exploded view you have excluded the star shaped first washer. does it stay fixed or does it move freely?

  74. #74
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    Quote Originally Posted by Dougal View Post
    To unscrew the shaft without damaging it you can make a shaft clamp from a piece of aluminium or other soft metal.
    Drill a hole through as close as you can to the size of the shaft and then saw a slot through it. Use these in the vice to get enough grip without damage.

    Alternately, you can try wrapping a piece of inner tube around the shaft so it grips your wooden blocks better.
    I needed some heat to get mine of be gentle though.

  75. #75
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    IFP debth and Oil:
    Press the IFP floating piston down as the shaft pushes it down, when you screw the bearing on the body.
    Unscrew the bearing again and give the IFP piston a small notch (1 or 2 millimeters)
    And you will be fine..
    NOW close the Nit. valve so you cant move the IFP piton down more.
    fill it with oil and screw the bearing back. try and get as little (NO AIR) in the body together with the oil.
    See the rock shox video here:
    RockShox Monarch Rebuild - YouTube



    I think the models 2008 and up uses 300/400 PSI Nit. or "air"
    Oil 10wt (but again is a broad term) stick with the known manufacturers)
    No guaranties guarantied
    Last edited by SteelKof; 01-15-2012 at 08:20 AM.

  76. #76
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    I drilled a hole into a nylon block 9mm drill bit. then cut the block in two and used the pieces in the vice.

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    edit

  78. #78
    I work in .001 tolerances
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    Look for my post: Fox RP3 unserviceable!?!?!

    There are pics of my rebuild, pics from Foxs' web site showing a rebuild and a link to the Fox bible that has all the info you could possibly need

    Joe

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    New question here. Please Help with my DT Swiss shock!

    Hi there! I have been searching the forum for quite some time, and found a lot of usefull info, on fork and shock rebuilds. Due to my low nr. of posts (actually 0 until now), I am not allowed to start my own thread so I hope no one will be hard on me for asking this in this thread.

    I have a DT Swiss SSD 225 damper (I think it's identical to the 210 only no lockout, just rebound). I have serviced the main air chamber, greased with Finish Line teflon grease (cannot find Slick Honey in Romania), holds air perfectly, seals ok.

    The problem is, I think (sure of it) I have air in the oil, as for the first 1 cm of travel or so, it poses very little compression resistance and has a loud suction (smacking) sound. Also, the shock achieves only 60% of it's travel, and is very progressive when inflated for the correct sag.

    There seems to be a tiny bit of oil around the rebound knob, near the head eye of the shock, a sign that I have been loosing oil. Does the rebound knob have an o-ring to stop oil flowing through the hollow shaft leading to the knob?

    Also, the shock has a triangle like screw to gain acces to the IFP gas chamber. Do you guys know if it's a Schrader valve underneath or rubber membrane (like the FOX)?

    I cannot find ANY information regarding DT Swiss shock rebuilds for the negative chamber, and you guys are all I have.

    IFP depth, pressure and oil weight are complete unknowns to me, and DT of course is not answering my questions. I also have no ideea what valve adapter I could use (in case it does have a valve), maybe one for the RS Monarch (the red one) would work?

    Thank you guys, and I hope someone can share some knowledge!

    Tudor

  80. #80
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    Quote Originally Posted by donpinpon29 View Post
    so that brings the second question up:
    how much and sae oil? heard its sae 10 but dont know how many cc´s or oil height ofr a 7,875 x 2 rp2
    thanks for your quick reply tacubaya gracias señor
    When I reassembled my shock, I couldn't find information on what type/weight of oil to use and my LBS didn't have shock oil. I ended up using oil that I put in my air tools that's made specifically for pneumatic tools. Since it's an air shock, I figured it should work.

    Now I know how it is that my shock seems to hold air pressure but blows out oil from the adjuster. It seems that it's a different gas "circuit" that's deeper inside. With the help of this great discussion and write-up, I surmise that the shock has blown out through the compression adjusted both oil and probably nitrogen. So, I guess into Fox it goes.

    What disturbs me a bit is that the shock only has about 200 miles of moderate trail riding on it, no jumping, big drops, wipe-outs, etc., yet has failed under my 160 lbs of weight. I hope that it holds up better after the rebuild.

    Thanks for the great write-up.

  81. #81
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    Leaky Compression Adjust, Stuck in Open

    Can anyone tell me if I'm doing any additional harm to the Triad by riding it without any compression adjust, and stuck in open position? My compression adjuster started leaking and I'm pretty sure that I've lost most, if not all of the nitrogen inside the unit, as it is holding air, but blowing oil. Based on this write-up, I'm guessing that I've lost the nitrogen. The bike is still ride-able, although it does seem a bit less stable. Comments? Thanks.

  82. #82
    PMK
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    Quote Originally Posted by MrRoundel View Post
    Can anyone tell me if I'm doing any additional harm to the Triad by riding it without any compression adjust, and stuck in open position? My compression adjuster started leaking and I'm pretty sure that I've lost most, if not all of the nitrogen inside the unit, as it is holding air, but blowing oil. Based on this write-up, I'm guessing that I've lost the nitrogen. The bike is still ride-able, although it does seem a bit less stable. Comments? Thanks.
    Order a new second shock. Once it arrives send that one in for repairs.

    FWIW, it may seem ridable, but depending on how it failed, more than likely it is the equivalent of taking a ball peen hammer to the internal parts with every bump. Maybe not quite that bad, but still not proper.

    PK
    Reps! We don't need no stickin' reps!

  83. #83
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    Quote Originally Posted by MrRoundel View Post
    Can anyone tell me if I'm doing any additional harm to the Triad by riding it without any compression adjust, and stuck in open position? My compression adjuster started leaking and I'm pretty sure that I've lost most, if not all of the nitrogen inside the unit, as it is holding air, but blowing oil. Based on this write-up, I'm guessing that I've lost the nitrogen. The bike is still ride-able, although it does seem a bit less stable. Comments? Thanks.
    Do not ride it.

  84. #84
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    Thanks for your input.

    Thanks for your input, guys. I guess I won't be riding it. I'll send it in to Fox tomorrow. That sort of sucks, but that's life.

  85. #85
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    Quote Originally Posted by PMK View Post
    Order a new second shock. Once it arrives send that one in for repairs.
    This is a good idea. Wish I had done it when the Triad for my bike was still available. Now they don't offer replacements so the bike has to be out of commission during a rebuild.

  86. #86
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    Great thread (like the many others) for those that are into the topic. With that said I'll continue it with hopes someone can help and further educate. So grab a beer and have a laugh!

    The infamous propedal rod o-ring on my RP2 released all the oil past the lever and into the air chamber. I can reassemble it except for the shim stack. A co-worker came by and wouldn't shut up. Now I can't remember the order it goes together.

    Referencing the image below, I've seperated the puzzle into columns that I know group together. Basically I forgot the order of these columns and in which they're assembled.
    Breaking and entering the damper circuit on a Fox air shock-shims.jpg

    With that said if anyone can answer what they can...
    1) From top to bottom in what order would these colums be assembled?
    2) What's the name of the piston at the bottom of #2?
    3) The valve at the top of #4, does the 'triangle' face up or down when assembled?
    4) The valve at the top of #3 (it's upside down), again does the 'triangle' face up / down?
    5) The conical washer (there's only one) at the bottom of #3, does the larger face go up or down when assembled?

    But wait there's more...
    1) There are definitely four shims in column #1. Not sure about five, or where would it go anyway.
    2) Where the heck would the shims in column A go? I'll take educated guesses on this one. I've referenced some exploded views throughout the interwebs but all tunes are not the same.

    Cheers!
    CRAP... I'm in the wrong gear

  87. #87
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    Check the photo of my rp2 shaft disassembled. Keep in mind that my rp2 came oem in a giant reign and rebound tune is medium and compression tune is hard, so shim stack could change compared to yours. Good luck

  88. #88
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    ↑↑↑ Thanks. I got a duplicate on ebay and going to strip it down albeit more meticulously after the holidays to use as a reference. Basically I was curious about the innards and their respective functions. Eventually I want to learn the theory behind the parts and how to customize for my weight and riding. I'm surprised at the general lack of resources regarding this topic around the web.

    I'll post back here if I have any questions.
    CRAP... I'm in the wrong gear

  89. #89
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    Sorry but why i can't see pictures on the first post ????

  90. #90
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    I updated the links in the original post. The got wiped out when Apple closed down mobile me.

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    Sorry to resurrect an old thread, but I found this Korean blog of some guy (Or company?) rebuilding a whole whack of forks and shocks. Unfortunately I couldn't find much technical info after using Google translate, but there are many, many pics of shock internals.

    This page in particular is a DT Swiss SSD 190L rebuild which is of great interest to me because I have one

    Link

    If you scroll all the way down you'll see that there are over 400 pages!

    I hope this link is not old news.

  92. #92
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    hi there.

    I'll just leave this here



    Fox Triad ?????????? ????????, ????????????, ??????

  93. #93
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    Quote Originally Posted by IUSius View Post
    hi there.

    I'll just leave this here



    Fox Triad ?????????? ????????, ????????????, ??????
    I'm sure that acheives their propedal goals quite well. But does it open far enough to get out the way on high speed impacts and stop spiking?
    Owner of www.shockcraft.co.nz and NZ Manitou Agent.
    www.dougal.co.nz Suspension setup & tuning.
    SPV Devolve

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    damping mode propedal copes well with the buildup, and at the same time allows the shock to go to 100% of its stroke, just compression characteristic becomes more intense than in the open mode

    medium speed shimstack, such a high speed / lockout stack have a some preload after turn piston bolt





  95. #95
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    damper seal kits

    Quote Originally Posted by IUSius View Post
    damping mode propedal copes well with the buildup, and at the same time allows the shock to go to 100% of its stroke, just compression characteristic becomes more intense than in the open mode

    medium speed shimstack, such a high speed / lockout stack have a some preload after turn piston bolt




    i hope you guys won't consider this as spam. i thinck the link can help the diy riders -
    Fox Float R RP2 RP23 RP3 Triad Improved Oil Seal Kit | eBay

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