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  1. #1
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    front derailleur adjustment question

    I have an LX front derailleur. When in the middle chainring the chain rubs in the lowest and highest rear cog. I have to trim it on both sides. Other than that it shifts great. Is something out of whack or should I bend the cage? Thx.

  2. #2
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    -Loosen the cable by turning the turny thing on your shifter, clockwise a bit.

    After it works, if something's still not right, take it to an expert.
    I'd tell you to move the screws around, but judging by the fact that you'd be willing to trim a derailleur, I advice against that not.

  3. #3
    wyrd bi ful rd
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    You can get the same ratio as middle chainring and large sprocket by shifting to small chainring and a smaller sprocket. You do not usually want to keep your chain at middle chainring and large sprocket as you can see (from the rear of your bike) that the chain is quite heavily distorted ...

    20080719 54_559 wheels 175mm cranks 9 Speed 11_32 gearing gain ratio MTBR FORUM.jpg

  4. #4
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    Quote Originally Posted by Garlock
    -Loosen the cable by turning the turny thing on your shifter, clockwise a bit.

    After it works, if something's still not right, take it to an expert.
    I'd tell you to move the screws around, but judging by the fact that you'd be willing to trim a derailleur, I advice against that not.
    lol. I have gripshift. Trimming means adjusting front derailleur one click either way to slightly adjust. Did you think I meant shaving the edges with a power sander or something?

  5. #5
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    Thanks for the chart chinaman. Good point.

  6. #6
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    Hi Chinaman...could you please explain what that chart means...I am novice on this chain ratio thing. thanks.

  7. #7
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    to the op, I run a 2x9 drivetrain (36/22) so I don't have to shift

    most of the time. I can run up and down all rear cogs with no rub on the fdr, from the 36t ring, all day long. All I did was remove the small screw from the rear of the fdr cage, insert a small washer, then replace screw. What this does is spreads out the rear of the derailler slightly, which allows you to run the top and bottom cogs with no rubbing. I have done this on several bikes.With Gripshift, it makes it even easier to trim the fdr, if needed. Even Shimano is going to 2x9- there is very little reason to run 3 rings for most of us- the chart posted proves it.

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