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dhx air 5.0 knocking

shieldsy94shieldsy94 Posts: 342
edited December 2010 in MTB workshop & tech
hi, got a problem with my fox dhx 5.0 air on my marin quake. Basically when i start going through the travel i get a knock from it. It only occurs when theres no preload on the shock and doesnt do it when its sagged.

Is it related to the shock or the frame as im unsure whether its the bushings or something inside the air can.

Posts

  • nicklousenicklouse Posts: 50,675 Lives Here
    hand over every joint. Shock/suspension and feel for play.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • thel33terthel33ter Posts: 2,684
    Much more likely to be a worn bushing, otherwise it would happen regardless of it being sagged.
    And now you know, and knowing is half the battle
    05 Spesh Enduro Expert
    05 Trek 1000 Custom build
    Speedily Singular Thingy
  • wycombephilwycombephil Posts: 123
    Agree with thel33ter - shock bushes are generally the best place to start looking for knocking noises.

    To test it I put one foot on the back wheel, one hand on the saddle and one hand on the shock. Pull the saddle up and down and see it you can feel any movement in the shock. If not the try the same thing on the other pivots on the frame.
  • shieldsy94shieldsy94 Posts: 342
    wycombephil wrote:
    Agree with thel33ter - shock bushes are generally the best place to start looking for knocking noises.

    To test it I put one foot on the back wheel, one hand on the saddle and one hand on the shock. Pull the saddle up and down and see it you can feel any movement in the shock. If not the try the same thing on the other pivots on the frame.

    lol i thought you said you had 3 hands :lol:
    yeah its not the bushes there fine, its like when i start a compression stroke quite vigorously (like hitting the landing rampof a jump for example) it makes a clunk. Like somethings catching somewhere :S
  • nicklousenicklouse Posts: 50,675 Lives Here
    then remove the shock and work the suspension through it travel and watch.

    also be aware of cables making noises.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • shieldsy94shieldsy94 Posts: 342
    nicklouse wrote:
    then remove the shock and work the suspension through it travel and watch.

    also be aware of cables making noises.

    this could be interesting on a marin quake :roll:
  • thel33terthel33ter Posts: 2,684
    The DHX has a second air chamber, on top of the regular one, so something could have gotten trapped in there, then when it is compressed it moves to the edge, making the noise.

    This is easy to remove, deflate, take the O-ring underneath it out, and pull down.

    The main air chamber needs to be unscrewed, it is meant to be hand tight, but I couldn't open mine at all :(
    shieldsy94 wrote:
    nicklouse wrote:
    then remove the shock and work the suspension through it travel and watch.

    also be aware of cables making noises.

    this could be interesting on a marin quake :roll:

    I'm sure you have a friend to help you :lol:
    And now you know, and knowing is half the battle
    05 Spesh Enduro Expert
    05 Trek 1000 Custom build
    Speedily Singular Thingy
  • shieldsy94shieldsy94 Posts: 342
    im gonna phone up mojo and tftuned tomorrow and ask what they say cause i cba to do that now :roll:
  • shieldsy94shieldsy94 Posts: 342
    Phoned mojo seen as though tftuned dont touch my shock :shock:
    anyway they said to give it a service or its a trapped o ring near the piston :(
    time to have a look inside it
  • thel33terthel33ter Posts: 2,684
    It shouldn't be hard to open it up, just deflate slowly, cycles the shock through its travel, deflate more, and twist the air can off. There may be a loud pop, that is normal. You don't have to deflate the boost valve thingy.

    The process is the same as this

    http://video.mpora.com/watch/KRTj23Tn7/
    And now you know, and knowing is half the battle
    05 Spesh Enduro Expert
    05 Trek 1000 Custom build
    Speedily Singular Thingy
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