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  1. #1
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    Installing a 20T chainring

    So I just put on a new 20T chainring which I downgraded from a 22 on my XT crankset with a 32 in back. Now, when I pedal in the granny, I'm getting skipping. It looks like the teeth are not matching up on the chain. Is the ratio off now? Is there a way to fix this problem?
    .nathan.

  2. #2
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    Quote Originally Posted by nathasm
    So I just put on a new 20T chainring which I downgraded from a 22 on my XT crankset with a 32 in back. Now, when I pedal in the granny, I'm getting skipping. It looks like the teeth are not matching up on the chain. Is the ratio off now? Is there a way to fix this problem?
    .nathan.
    Did you use a new chain?

  3. #3
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    New everything

    Quote Originally Posted by MikeDee
    Did you use a new chain?

    Yep, new chainrings, new cassette, and new chain.
    .nathan.

  4. #4
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    first make sure you got the chainring orientation right.
    I suspect that the chain might be a bit long, check out the tension when in the granny.

    Quote Originally Posted by nathasm
    Yep, new chainrings, new cassette, and new chain.
    .nathan.
    [SIZE=1][/SIZE]

  5. #5
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    Quote Originally Posted by logbiter
    first make sure you got the chainring orientation right.
    I suspect that the chain might be a bit long, check out the tension when in the granny.
    Also it might make a difference which side of the chainring faces in towards the bike.

  6. #6
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    Look closely at the inside (nuts) - Does the chain rub ever so slightly on them? Rising up just a barley noticeable amount?

  7. #7
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    Quote Originally Posted by nathasm
    So I just put on a new 20T chainring which I downgraded from a 22 on my XT crankset with a 32 in back. Now, when I pedal in the granny, I'm getting skipping. It looks like the teeth are not matching up on the chain. Is the ratio off now? Is there a way to fix this problem?
    .nathan.
    Where did you get a 20T chainring for an XT Crankset? I thought 22T was the smallest for a 64 BCD.

  8. #8
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    Quote Originally Posted by spinjocky
    ... 22T was the smallest for a 64 BCD.
    I believe this is true, (unless there's some custom/special set-up outthere somewhere).
    Compact drives (58 BCD) are the only one's that can run a 20T small. (Or is it an 56 ?)

  9. #9
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    second that

    Quote Originally Posted by spinjocky
    Where did you get a 20T chainring for an XT Crankset? I thought 22T was the smallest for a 64 BCD.
    Where did you find a 64 bcd 20t chainring? I have a 22 on my bike and it seems that the chain is right on top of the chainring bolts. I use a 34t big cog in back to get the same thing you are after. A crazy low granny gear.

  10. #10
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    Boone

    It's a boone titanium chainring. I got the 20 and a 32 made for my XT crankset.
    .nathan.

  11. #11
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    Talked to the boys at Cycle Dynamics today re your 20 tooth granny gear on a 64 BCD crank. They don't make 'em cause they don't always work.
    Quote Originally Posted by nathasm
    It's a boone titanium chainring. I got the 20 and a 32 made for my XT crankset.
    .nathan.
    Attached Images Attached Images

  12. #12
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    Quote Originally Posted by pimpbot
    ... chain is right on top of the chainring bolts.... crazy low granny gear.
    With 9-sp (34 rear cassette) I've seen problems getting a 20T front to work well.
    8-sp (32 rear) with the right nut-bolt combinations can work w/ 20T front.
    Then again - I haven't seen a 9-sp compact drivetrain. There might be some special made somewhere, but none that I've ever heard of. [Edit] I takes this back, There's plenty of 9-sp compact, I was thinking purley Shimano [/Edit]


    Quote Originally Posted by nathasm
    ... I got the 20 and a 32 made for my XT crankset...
    I think you mean; "It's made for a compact crankset". I doubt they made one ring just for you, unless you’re a sponsored racer.
    Then again a sponsored racer rarely goes in the small ring, so ....

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