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  1. #1
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    ghost shifting problems

    im looking for a few words of advice, or a solution to a problem thats still eluding me. - new bike, as of yet unridden out of the workshop, with a nasty ghost shift under load.

    frame - kinesis maxlight (easton ultra light) 18"
    cranks - xt hollowtech II
    chain - sram 99 hollowpin (no split link, chain is hard joined)
    cassette - sram pg980 11-32
    mech and shifters are sram x7

    ive been working with bikes for a number of years now, put ive never had such trouble...

    the chainline is set central (middle ring + 5th sproket produces straight chain line) ive removed the split link, ive tried a few different chain line spacings on the BB, rd is adjusted perfectly with brand spaking new clarks preium cables.

    under load (load considerd to be hard in saddle acceleration, or climbing in the saddle) the chain will jump up the cassette onto a larger sproket, it does this in all 3 front rings, producing a potential face + stem smash.

    the frame is a very lightweight (1600g ish) ride, it has got a fair amount of flex in it, but not so much to lengthen the gear cable run enough to cause an upshift.

    now can anyone here think of anything ive missed out in hunting for the problem ? or have any other ideas how im going to sort out my new steed ?

  2. #2
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    Ghost shifting is usually associated with a flexy frame with a weak rear triangle. The off-center pull of the chain flexes the rear triangle to the right and pulls the chain off of the cog it's on. Usually the ghost shift is to a smaller cog so what you report is unusual. I don't think its a cable problem though.

  3. #3
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    i know for a fact the mech and cage are fine, since they are from my last bike - ill look into the hanger next chance i get (wednesday)

  4. #4
    Banned wagathon's Avatar
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    Are the cogs warn, e.g., instead of U-shaped, does one side have more slope?

  5. #5
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    Quote Originally Posted by wagathon
    Are the cogs warn, e.g., instead of U-shaped, does one side have more slope?
    the cassette is next to brand new, were talking less then 10 miles.

  6. #6
    Banned wagathon's Avatar
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    Quote Originally Posted by The Great Stonk
    the cassette is next to brand new, were talking less then 10 miles.
    Then, are you using the same old chain? If so, many miles on it?

  7. #7
    Retro-nerd georgiaboy's Avatar
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    right, the chain being stretched could be the cause of this problem
    Would you like a dream with that?

  8. #8
    fitter, happier Ronin's Avatar
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    Quote Originally Posted by HillRider
    Ghost shifting is usually associated with a flexy frame with a weak rear triangle. The off-center pull of the chain flexes the rear triangle to the right and pulls the chain off of the cog it's on. Usually the ghost shift is to a smaller cog so what you report is unusual. I don't think its a cable problem though.
    Plus one. I'm guessing your rear cable runs under the BB? Frame flex causing the cable to tug. Look at the cable guide and provide the slickest lube you can find.

  9. #9
    Senior Member Chongo's Avatar
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    Don't forget to check your rear derallieur hanger alignment.

  10. #10
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    chain is also new im afraid, cable run is along the top tube too...

    cant check the dropout hangar untill weds im afraid, ill give yall an update when i do.

  11. #11
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    success!

    the hangar was slightly twisted (barly noticable to the eye, but the apropriate toolage revealed it) bent it back, and orderd 2 spares for the future, and it seems no amount of practice gate starts will make it jump out of gear

    cheers fellas, ill see about getting a few pics of my new steed up

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