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Thread: RX clunk

  1. #1
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    RX clunk

    2005 RX 100 with a 2000 Fox Float R pushed in 2005.
    I have been trying to locate a slight clunk for a very long time and its time to appeal here for help. I only experience the clunk on the rebound of a big dip rather than a square hit. Picture a 5 foot wide culvert ditch where the contraction to full travel is smooth, then when the rebound tops out, I feel the clunk. This clunk does not affect handling in any way and happens only a few times per ride and I can predict the points on the trail where I will feel it.
    I have tested all bolts and my wheelset and I canot reproduce this clunk in any shop conditions. The entire swing arm is original from June 2005. I have never disassembled it, but I can find no play here. My shock is old but maintained. I dislike replacing it without knowing it is to blame. RP23 would be nice, but cash controls are on.

    Thanks in advance for any input.
    Mike
    MCM # 57

  2. #2
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    You may have already done this, but have you checked every frame junction for cracks? Have you tried alternating approach in these sections just to see what would happen (such as standing during these dips, or vice-versa)?

    Ovalized pivot bores (especially around the shock)?

  3. #3
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    Probably not what is happening to you, but I took an X on it's maiden voyage last friday. Kept getting a weird clunk and could not trace it down. First thought it was the head set, then found it coming from the rear of the bike. The rear derailleur was hitting the drop out in certain gears on rebound. I have increased b tension and think this should fix it. May be worth checking and is easy to adjust and even better free. Good luck.

  4. #4
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    Thanks for the suggestions

    I, too have felt the rear derailler pull under the same full range suspension activity. Even though the chain length is correctly measured and set up. B tension is something I will look into. I try to keep the pulley as close to the cog as possible.

    As far as frame cracks, this problem has persisted through many frame cleanings and waxings for the dual purpose of finding cracks. I even have a giant magnifying glass to rule out scratches as cracks. It can't hurt to check again.

    Thanks for sharing
    MCM # 57

  5. #5
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    Have you ever changed bearings and bushings in your frame and DU bushings in the rear shock??

    If not, I'd start there.... it will cost you around $100 for a complete bearing and bushing re-build.

    If you do this and continue to get this problem, I'd suspect your shock is making the noise.

    Regards,

    EndUser
    My advice and $3 will buy you nothing more than a tunafish sandwich.

  6. #6
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    Good one

    I have done DU bushings and reducers before. I know what these feel like, and in my experience, can be detected in any point of travel range. I have never attempted the horst and pivot bushing kit. All these are original. I do not get lateral play. Since I can only feel this on the completion of rebound on a slower-type full travel, I also suspect the shock. I was just looking for certainty before replacing somthing this pricey. And I have lived with this sublety for sometime.
    Thanks for the tips
    MCM # 57

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