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  1. #1
    Member trekdude's Avatar
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    Grinding noise from IGH.

    I've been commuting locally around town in my Novara REI IGH (SHIMANO 7speed). One day I decided to carry a heavy load (around 20-25 pounds on my pannier rack and I had to jump off the curb due to an emergency. My bike pounded the pavement hard from jumping off the curb. Next, I started hearing a low grinding noise from the IGH. I ignored the noise and three days later, the grinding noise became louder and louder. I stopped riding this bike and switched off to my fixed gear. Anyone who has a IGH experienced such a noise from the IGH? What can be wrong with it since I can see the gears inside from my naked eye. Please help!

  2. #2
    On a Mission from God FunkyStickman's Avatar
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    Sounds like you might have stripped a gear... if you're adventurous, you could try opening it and seeing, but chances are it will need to be repaired. Does it make the sound in every gear, or just in certain ones? If it's only in certain ones, then it's very likely a messed up gear. Shift it into your 1:1 gear (should be 4th on that hub) and see if it still is grinding.

  3. #3
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    Quote Originally Posted by trekdude View Post
    Anyone who has a IGH experienced such a noise from the IGH? What can be wrong with it since I can see the gears inside from my naked eye. Please help!
    Oftentimes frame flex or even a little tug at the shifter cable can cause the gearing calibration to get off. Then, you'll hear grinding in some gears. So, whenever the Shimano IGH gears get a little crunchy, always check that your gearing calibration is okay. If you don't know what this means, then check out: http://www.sheldonbrown.com/nexus-mech.html

    Hopefully, this is the problem and not something major. Good luck!

  4. #4
    Senior Member coldfeet's Avatar
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    Quote Originally Posted by trekdude View Post
    since I can see the gears inside from my naked eye. Please help!
    Do you mean that you can actually see the gears from outside the case? If so, I'm guessing you have broken the axle, and the hub case is spreading apart. Not sure, as have not worked on these. Anyway, if you can see the gears, you have at least a rebuild if not a replacement in your future.

  5. #5
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    I suspect the OP dropped a 't on the can...

    If he CAN see the gears inside - please take a picture! This would indeed be an interesting hub...

  6. #6
    Member trekdude's Avatar
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    **** I had a typo. I meant I CAN'T see the IGH from the outside. The grinding noise is not from shifting. It's just from basic peddling .

  7. #7
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    First try adjusting the cable tension. Shift into whichever gear is highlighted in red on the shifter window. Then, clean off the little clear plastic window on the hub down near the dropout. You'll see two little marks, which should line up. (If your hub is older, it may have two little metal fingers instead of marks inside a plastic window.) Twist the threaded adjusting barrel of the shifter cable, usually located on the shift lever, until the two marks line up.
    If your grinding is still there after the adjustment, then you'll need to think about having the hub itself serviced.

  8. #8
    tcs
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    Quote Originally Posted by FunkyStickman View Post
    Shift it into your 1:1 gear (should be 4th on that hub) and see if it still is grinding.
    There's actually not a 1:1 on a Nexus 7; every ratio is created through one or two planetaries.

    tcs
    "When man first set woman on two wheels with a pair of pedals, did he know, I wonder, that he had rent the veil of the harem in twain? A woman on a bicycle has all the world before her where to choose; she can go where she will, no man hindering." The Typewriter Girl, 1899.

    "Every so often a bird gets up and flies some place it's drawn to. I don't suppose it could tell you why, but it does it anyway." Ian Hibell, 1934-2008

  9. #9
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    Quote Originally Posted by tcs View Post
    There's actually not a 1:1 on a Nexus 7; every ratio is created through one or two planetaries.

    tcs
    Fourth gear (or whichever one is highlighted on the shifter window) is the gear at which you actually get whatever your chainring/rear cog combination is. That is the 1:1 gear from which adjustments are made.

  10. #10
    on your left.
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    Quote Originally Posted by Rhodabike View Post
    Fourth gear (or whichever one is highlighted on the shifter window) is the gear at which you actually get whatever your chainring/rear cog combination is. That is the 1:1 gear from which adjustments are made.
    accurate.
    Quote Originally Posted by caloso View Post
    I learned this the hard way. They say that experience is the best teacher, but I would have been preferred to just read about it on the internet.

  11. #11
    Commander, UFO Bike K'Tesh's Avatar
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    Also you should check for cracks in the frame... I've busted them at the dropout end of the chainstay, and now at the BB end of the chainstay/seat tube. It made it's odd noise when I was pedaling, or any time the frame flex'd.

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