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  1. #1
    meh....
    Reputation: Monte's Avatar
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    Lefty Max SPV rebound clunk. Not top out clunk....

    Okay, I rebuilt my 140 Max SPV. Bearings out, reset, changed oil. The original clunk is still there. It isn't a top out clunk.

    Remove the spring, reinstall the spring keeper/preload/rebound knob assembly so you can stroke the SPV damper rod. Compress the fork, grab the top of the damper rod, push down slowly then pull up fast, clunk. I found it by riding down the driveway leaning down on the bars and pulling up quickly just enough to raise the bars 1"-2", but not nearly enough to top out the fork. I have a blue spring installed so I can hold the fork down into the travel a ways.

    Going to post in Shocks too.

    WTF?!?!
    Monte

  2. #2
    All Lefty's, all the time Moderator
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    Quote Originally Posted by Monte
    Okay, I rebuilt my 140 Max SPV. Bearings out, reset, changed oil. The original clunk is still there. It isn't a top out clunk.

    Remove the spring, reinstall the spring keeper/preload/rebound knob assembly so you can stroke the SPV damper rod. Compress the fork, grab the top of the damper rod, push down slowly then pull up fast, clunk. I found it by riding down the driveway leaning down on the bars and pulling up quickly just enough to raise the bars 1"-2", but not nearly enough to top out the fork. I have a blue spring installed so I can hold the fork down into the travel a ways.

    Going to post in Shocks too.

    WTF?!?!
    Monte
    Assuming it's fully bled, sounds like a bad rebound damper. Note, the top end is the rebound damper, it has nothing to do with SPV, other than it's in the same fork.
    This is a Pugs not some carbon wannabee pretzel wagon!!

    - FrostyStruthers



    www.mendoncyclesmith.com

  3. #3
    meh....
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    MendonCycleSmith wrote:
    Assuming it's fully bled,

    Should be. I filled it up and stroked the damper rod up and down with the fork inverted after I filled it with oil.

    sounds like a bad rebound damper. Note, the top end is the rebound damper, it has nothing to do with SPV, other than it's in the same fork.


    In the picture, what are you calling the rebound damper? And can I take this apart and diagnose further? Anyway I can fix and ride this sucker this weekend?

    Monte
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  4. #4
    meh....
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    Quote Originally Posted by MendonCycleSmith
    Assuming it's fully bled, sounds like a bad rebound damper. Note, the top end is the rebound damper, it has nothing to do with SPV, other than it's in the same fork.
    I'm assuming that blue is SPV, and the steel part on top of that is the rebound damper. I'm not seeing anything in there (I tore it down this morning) that could clunk. Nothing seemed loose. There's only a spring and a plastic valve needle inside. The needle doesn't follow the rebound adjuster rod up and down, but I'd assume it's because of the o-ring fits tight and it's not in oil being out of the fork.

    Help,
    Monte

  5. #5
    LA CHÈVRE
    Reputation: Dan Gerous's Avatar
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    How much pressure do you have in the SPV chamber? Under or close to the lower limit of 30 PSI, it clunks, that's what SPV forks do. Supposedly, that won't damage anything but it can be annoying, the solution is to put more pressure.

    DAN.GEROUS.NET : MOUNTAIN BIKING : CYCLOCROSS : ROAD :

  6. #6
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    In your picture, is the blue anodized cylinder (left of the light blue teflon ring) free to move to the right? In other words, can you push the cylinder easily such that the gap closes?

    After assembly did you pump up your SPV pressure to minimum pressure?

    The blue cyclinder is your SPV which needs to be closed for rebound to work properly. If the SPV pressure is not closing the valve, you will have no rebound damping for a split second. The flow of the oil then forces the valve shut which is the clunking you are feeling.

  7. #7
    All Lefty's, all the time Moderator
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    Quote Originally Posted by Monte
    MendonCycleSmith wrote:
    Assuming it's fully bled,

    Should be. I filled it up and stroked the damper rod up and down with the fork inverted after I filled it with oil.

    sounds like a bad rebound damper. Note, the top end is the rebound damper, it has nothing to do with SPV, other than it's in the same fork.


    In the picture, what are you calling the rebound damper? And can I take this apart and diagnose further? Anyway I can fix and ride this sucker this weekend?

    Monte
    That whole assembly is the rebound damper. No amount of dis-assemby will help at this point. If they do that, it needs to be replaced. Of course all this is based on the assumption that you know what you're doing, and that your descriptions of circumstances are being properly interpreted by me.....
    This is a Pugs not some carbon wannabee pretzel wagon!!

    - FrostyStruthers



    www.mendoncyclesmith.com

  8. #8
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    That picture looks like the SPV rebound assembly in a Manitou fork. The SPV valve can get sticky. Apparently the SPV valve uses a special grease. The easiest but not the cheapest fix is to replace the rebound assembly like Craig said. There are guys who have regreased the SPV valve with some success. Look up on the shock forum about regreasing the SPV valve. Like DG said you can increase pressure which makes the fork harsher or live with the noise.

  9. #9
    meh....
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    quote=Biandon
    In your picture, is the blue anodized cylinder (left of the light blue teflon ring) free to move to the right? In other words, can you push the cylinder easily such that the gap closes?

    Yes, that cylinder can move.

    After assembly did you pump up your SPV pressure to minimum pressure?

    Yes. Maybe 40 psi, don't remember offhand. But at least 30 psi.

    The blue cyclinder is your SPV which needs to be closed for rebound to work properly. If the SPV pressure is not closing the valve, you will have no rebound damping for a split second. The flow of the oil then forces the valve shut which is the clunking you are feeling.

    I'll try more pressure and see what happens. I did notice one of the o-rings inside the cylinder doesn't look great. Wonder if I can get a set of seals for the damper assembly.

    Monte

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