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  1. #1
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    Shifting Problems

    I have an unusual shifting problem. When the cable tension is good for upshifting, it is bad for downshifting and vice-versa. I have lubed the cables well and made sure that the high and low adjustments are proper, but I just can't seem to find a cable tension that works. Something that may be relevant is that when I am in the higher gears (smaller cogs) and I have just down shifted to somewhere in the middle of the cassette for instance, then immediately shift to a smaller cog, I have to pull the trigger twice before it shifts. Also, if I am in the smallest cog and shift to a higher gear the trigger button is very soft in the beginning of the shift. Also, I cannot shift into the largest cog without going to the absolute back of the push stroke. One more thing; on the stand the best compromise between up and down shifting translates to more hesitant shifting to smaller cogs when the bike is ridden.

    Other possibly relevant info:
    Prior to this problem the shifting has been very good.
    XTR trigger shifters
    XTR rear derailleur
    Moderately worn cassette XT and chain Sram 991
    Moto Fantom Team Frame

    Any help would be much appreciated.

  2. #2
    PCC
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    Have you replaced the cable and housing? Are the pivots on the RD worn and you have play in it? Is the rear derailleur hanger correctly aligned? Is the shifter worn? I'd start by replacing the cables and housing, first.

  3. #3
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    The housings and cables are only about 8 months old. I'm not sure the best way to tell if the RD pivots are worn. The hanger is aligned properly. How would I tell if the shifter is the problem?

  4. #4
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    I'm with PCC on this one. I think it's the housing, but a frayed cable could also be the problem. It's also possible that your derailleur or shifters are faulty, but I think this is significantly less probable.

    I've had almost identical problems with my drivetrain(s) in the past. I adjusted the cable tension over and over, attempted to lube the cable in the housing, and thoroughly cleaned the rear derailleur. None of those attempted fixes helped. What did solve the problem, at least for a while, was to replace the housing.

    After a couple of months of riding in dry, dusty conditions, the shifting problems returned. Again, replacing the housing fixed the problem. After a time, I found that I only really needed to replace the two rearmost housing sections. I tried to get a bit more life out of the housing by lubing it, but that never worked, at least not for very long.

    There's an exposed section of cable that runs along the seatstay (or along the upper part of the swingarm on a full suspension bike.) I think the dust is particularly prone to contaminating the housing at the two places where the cable enters the housing along the seatstay. I'm now running a single piece of housing all the way from the rear derailleur to the rearmost cable stop on the main triangle. This prevents the dust from getting in (at the aforementioned locations) and saves me from having to install new housing every few months. I've also tried running continuous housing all the way from the derailleur to the shifter; this works too, but I was not able to secure the cable well enough to prevent it from sliding back and forth when the suspension compresses and rebounds. I may revisit running full housing again in the future though.

  5. #5
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    Thanks for the advice KevinB and PPC, I will give changing the housings a go.

  6. #6
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    Ok, new housings worked, thanks guys.

  7. #7
    PCC
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    Glad we could help.

  8. #8
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    Looks like housing worked, but it sounded like a bent derailleur hanger to me.

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