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  1. #1
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    Unable to upshift/downshift smoothly with XT RD

    I am having severe problems out on the trails upshifting and downshifting. I put the bike on the rack yesterday to tune the RD. What I found is that when I upshift or downshift the RD remains in the same position. I even found a spot where pressing the shifter one up or one down didn't even move the RD.

    The problem started a few weeks ago. I had problems downshifting. I tuned the RD as best as possible on the trail but the problem never went away. The more I rode the bike the worse the problem got.

    Any ideas? Is the cable dragging or hanging? Do I need to clean and lube the RD?

  2. #2
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    My guess is that it might be a god idea into changing out your RD cables. Sounds like there's something is really making things stick.

    However, before you go and do that, undo the cable and see if you can move the derailleur manually. If it seems to move/shift ok while manually moving the derailleur, then more than likely, the problem is isolated to the cables.

  3. #3
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    Quote Originally Posted by dubjay
    My guess is that it might be a god idea into changing out your RD cables. Sounds like there's something is really making things stick.

    However, before you go and do that, undo the cable and see if you can move the derailleur manually. If it seems to move/shift ok while manually moving the derailleur, then more than likely, the problem is isolated to the cables.
    I was going to try that tonight. I was also going to pull the chain off and watch the RD move up and down to see how it acted and find out if the motion was smooth.

  4. #4
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    Quote Originally Posted by dubjay
    My guess is that it might be a god idea into changing out your RD cables. Sounds like there's something is really making things stick.
    I agree with this advice.

    Check the cable housing too. If the cable's not moving well, it may be that the cable is frayed, or it may that just enough dust and dirt have gotten into the housing to gum up the inside so that the (inner) cable won't slide smoothly. Sometimes, you can isolate it to a segment of housing. The segment which usually gives me the most problems is the one between the derailleur and the cable stop on the swing arm (or chain/seat stay on a rigid or hardtail bike). I've found that replacing this segment alone will often restore shifting performance.

  5. #5
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    UPDATE:

    I had to take my bike to the shop. I was playing with the brakes and my rear hydro line blew up. While there, I asked them to look at the RD as well. They suspected a bad cable or just crude in the housing. They fixed my brake and sold me a replacement cable. When I got home, I loosened the cable from the RD and began to pull it out. I could feel a lot of resistance in the housing. I pulled the cable all the way out and examined it. The cable was in great shape and very clean. I fed the cable back into the housing and felt the same resistance. I removed the cable and applied liberal amounts of teflon lubricant. This time the cable slid into the housing very easily. I reconnected the RD and everything is shifting bueatifully.

    Now I am a lover of all things mechanical and I should have suspected this. Before even taking it to the bike shop, I should have removed the cable and examined the housing. Now I have to drive all the way back to the LBS to return the cable.

    BTW, shifting is better than when the bike was new.

  6. #6
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    Quote Originally Posted by Lumbee1
    I loosened the cable from the RD and began to pull it out. I could feel a lot of resistance in the housing. I pulled the cable all the way out and examined it. The cable was in great shape and very clean. I fed the cable back into the housing and felt the same resistance. I removed the cable and applied liberal amounts of teflon lubricant. This time the cable slid into the housing very easily. I reconnected the RD and everything is shifting bueatifully.
    Consider hanging onto the spare cable. You'll need it eventually.

    You should also consider getting some fresh cable housing. I've tried different kinds of lube to rejuvenate old housing and nothing has worked all that well for me. Generally cables last a good long time for me; it's the housing that has to be swapped out frequently. (I ride in a very dusty environment though.)

    Anyway... glad to hear you tracked down the problem and that shifting is good again.

  7. #7
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    Yep, more frequent housing service is the ticket; unless the cable is kinked or frayed keep using it.
    "...the people get the government they deserve..."
    suum quique

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