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  1. #1
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    XTR M970 Shifter, Is this normal operation?

    I recently bought a set of the 2007 XTR rapidfire trigger shifters to go with my matching front and rear 2007 XTR derailleurs and noticed an odd behavoir when I shift to a larger rear cog (high normal rear setup) on the right hand shifter. A few times when I shift down (larger rear cog) with the aluminum shift lever (push) it will move say one gear and then break away like something broke inside and not actually move the cable further. Once I release the lever it's fine and operates normally. It has done this two or three times in 4 or 5 hours of riding. Is there a designed in break away feature (due to high loading or something) in the mechanism or is my rear (right side) trigger shifter malfunctioning?

  2. #2
    Mantis, Paramount, Campy
    Reputation: Shayne's Avatar
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    Sounds Like Its Gummed Up

    I've had that happen with several different shifters in the past when the grease was old and/or dirty. The springs get stuck in the retracted position and allow the shift lever to turn freely without "catching" on the indented shift disc and pulling the cable to the next position.
    If you got them new I'd return them.
    If they were used I'd open them up and clean and lube the shift mechanism.
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  3. #3
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    Ya I did get new but on ebay so returing them may be a problem. Maybe I need to crack the right side one open and see if Shimano over greased them.

  4. #4
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    Is your rear derailleur cable loose? When installing, what can happen is that the cable end inside the shifter can actually be loose, so that the holder is not actually holding the cable end (looks like a metal cylinder). If the cable is actually loose, you will have issues kinda like what you described. Good luck.

  5. #5
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    tk1971, I don't think the cable is loose because it operates normally 95% of the time. When I first noticed the odd operation the shift lever started to shift the rear de but then just swiveled with no cable resistance, like the internal gearing was gone. I thought I broke the lever off. But after releasing the lever it worked fine on the second stroke. That's why I thought that maybe Shimano designed in a break away feature so that you can't overload the mechanism if the loading is precieved to be too high. I can't find any notes on this anywhere if it is in fact a feature. Very odd though.

  6. #6
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    [SIZE=3]I’m with Shayne on this one. The grease that Shimano puts in their shifters is pretty thick. On new shifters, it’s not normally an issue, but they can start to feel gummed up when it gets cold outside. There’s a spring loaded ratchet in there that will go one click, then stick open because of the grease. I don’t recommend opening up the shifter. If that sounds like what’s happening in your case, there’s really no need to crack open the shifter. [/SIZE]

    [SIZE=3]Get some White Lightning and saturate the inside of the shifter with that stuff. Work the shift levers back and forth and this will help ungunk some of that grease. It REALLY helps doing this if you have access to an air compressor. If you do, get the air nozzle from the air compressor to an opening in the shifter and blow the White Lightening out. They should click much better after that.>>[/SIZE]
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  7. #7
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    Quote Originally Posted by ignazjr
    [SIZE=3]Iím with Shayne on this one. The grease that Shimano puts in their shifters is pretty thick. On new shifters, itís not normally an issue, but they can start to feel gummed up when it gets cold outside. Thereís a spring loaded ratchet in there that will go one click, then stick open because of the grease. I donít recommend opening up the shifter. If that sounds like whatís happening in your case, thereís really no need to crack open the shifter. [/SIZE]

    [SIZE=3]Get some White Lightning and saturate the inside of the shifter with that stuff. Work the shift levers back and forth and this will help ungunk some of that grease. It REALLY helps doing this if you have access to an air compressor. If you do, get the air nozzle from the air compressor to an opening in the shifter and blow the White Lightening out. They should click much better after that.>>[/SIZE]
    When you mentioned "cold outside" that turned on a light. Both times the air temps were in the low 30's deg F so I bet this is the problem. I do have an air compressor so I will try blowing in some lower viscosity lube and see if that helps.

    Hey thanks all for the great suggestions!!!

  8. #8
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    I've had this happen to me as well. It happened to me when I would catch the release lever with the side of my thumb. make sure that is not whats happening to you as well. when you shift the thumb lever past the release lever, if your thumb is on the very upper end of the thumb paddle you can catch the release lever and the shifter will skip. now that I know what made my lever skip I've not had it happen again.
    I hope tthis helps you.

  9. #9
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    Quote Originally Posted by Dover
    I've had this happen to me as well. It happened to me when I would catch the release lever with the side of my thumb. make sure that is not whats happening to you as well. when you shift the thumb lever past the release lever, if your thumb is on the very upper end of the thumb paddle you can catch the release lever and the shifter will skip. now that I know what made my lever skip I've not had it happen again.
    I hope tthis helps you.
    Great tip. I definitely am not use to all the ways this shifter can function so I will be more careful about my thumb placement.

  10. #10
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    release in both directions

    Quote Originally Posted by parfilator
    Great tip. I definitely am not use to all the ways this shifter can function so I will be more careful about my thumb placement.
    yeah, becasue the realease lever can release in that direction, catching it with your thumb can make it feel like its skipping.

  11. #11
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    Quote Originally Posted by Dover
    I've had this happen to me as well. It happened to me when I would catch the release lever with the side of my thumb. make sure that is not whats happening to you as well. when you shift the thumb lever past the release lever, if your thumb is on the very upper end of the thumb paddle you can catch the release lever and the shifter will skip. now that I know what made my lever skip I've not had it happen again.
    I hope tthis helps you.
    yup, this happened to me too. i thought the shifters were defective until i realized my thumb was hitting the release lever. it hasn't happened since now that i am more careful with thumb placement. nice shifters.

  12. #12
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    Dover/Phil, you guys are spot on. I was fiddling with the shifter with my bike on the work stand and was able to repeat the problem with thumb placement that was too high on the trigger. Seems like a newbie problem but apparently not so unusual. Funny thing is I don't recall ever feeling the contact (that causes the release) with the finger shifter while riding.

  13. #13
    trail "cleaner"
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    Yepper...

    Been there, done that as well. Thought I broke the darn thing when it happened. I was doing a multiple cog shift (quickly) and my thumb hit the release lever as I pushed the main lever and the thing jut went all the way to it's limit with no tension... Instantly went ... (OH CRAP) just broke my $$$$ shifters... only to push the lever again and all was well. Never had this happen on all of my 952 shifters though..
    No dabs allowed!

  14. #14
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    how are you guys orienting your shifters on the bars? i initially set these up with the shifter body roughly parallel with my brake levers (basically rotated up until the top of the shifter body contacts the bottom of my J7 brake lever. my brake levers are oriented at roughly 45 degrees with respect to horizontal. i was just playing around with them, and they feel slightly better if i rotate them down a bit (i.e., with the shifter body closer to vertical). hard to tell in my garage if this is really better (and ytoo cold outside to test ride).

    my 952's never did this either. i think were noticing this on the new ones because the trigger protrudes further rearward (to enable thumb operation).

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