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  1. #1
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    Chain rub on chainstay

    I have an Intense Spider XVP. The bottom of my chainstay by the bottom bracket is getting a lot of chain rub, and I can't figure out anything to alleviate it. I have an XTR crankset and XO rear derailleur. It happens worst (of course) when I'm on the smallest rings in both front and back, but still happens on the smallest three or four on the cassette. I noticed my brother gets a little bit of it on his Blur XC with very similar geometry, though not as bad - he's running a Race Face crankset. Any advice? It's beat up pretty good already.

    Any way to fix this other than the obvious "avoid the small-small combos and shift to middle ring"? I'm wondering if I can tighten the chain a bit or if that's asking for more trouble -- it is now at the appropriate length, though I could probably pull a link.

    P.S. Apologies for cross post (I started this in the Intense forum, but probably best here)

  2. #2
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    I'm not familiar with your frame's geometry, but there should be decent clearance between the chainstay and the straight line from the bottom of the small chainring to the RD. Is the wear because of chain slap on bumps, or is a bit of chainsuck bringing the chain up into the stay?

    If it is simply a matter of narrow clearance shortening your chain won't really help since it won't meaningfully change the chain tension. Pad the bottom of the chainstay the way most people have to pad the top of theirs. If all the damage is concentrated up near the BB, I'd suspect that there's a bit of chainsuck happening, which needs to be dealt with.

    It might also help if you post a photo here.
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  3. #3
    fnar fnar brrraaaaap
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    it will happen when you ride a bike with certain designs....and the only thing i can think of is to wrap and tube around this area and zip tie it on.

  4. #4
    local trails rider
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    Generally, you should avoid the small/small and big/big combinations: the chain has to bend sideways quite a lot in those combinations. In small/small, the derailer has a lot of slack chain to handle.

    On almost all geared bikes, you get chain slap when going over bumps. Wrap some inner tube around the stay, as suggested. There's commercial products too, but they don't do a better job. Sometimes they do worse.

  5. #5
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    you can install a chain guide that will help with the chain slap.

  6. #6
    Rub it............
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    The problem is in the gear selection that you are using.

    The rear derailleur is there to help keep proper chain tension. When you go to the small/small combo the derailleur is pretty much folded up on itself and is not able to keep proper chain tension. Therefore the chain has excess slop in the drivetrain and it flops around. See picture for example.



  7. #7
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    if thats the case the previous poster is right, but if this is not happening and you just have a small amount of chain looseness the chain guide with the tension roller would cure your problem.

    Last edited by thebluesbox; 04-05-2009 at 08:29 PM.

  8. #8
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    Thanks -- it seems to be the geometry. Here are a couple of shots small-small and big-big. Sounds like removing a link wouldn't help enough, and may be a bad idea regardless. Chain tensioner as the last poster suggests? Though perhaps just avoiding the tricky combos is what I need to do. I've looked at the Chain Reactor but welcome any suggestions and best for this geometry and VPP. Thanks again!
    Attached Images Attached Images

  9. #9
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    I dont think removing links is the answer because you will have trouble when you go big big. I would do like you said avoid the two combos. I think the geometry is the problem like you said, the swing arm frame does seem really at a high up angle, my bike has a lower down slope to the chain stay and thats why I dont recall having this problem. Im not sure what the technical way is to fix it right, but until then I would avoid using big big and small small.

  10. #10
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    Your swingarm pivot is so low that there might be chain slap in any gear combo using the granny. I suggest simply protecting the impact area and replacing the protection as needed.

    Another alternative is going to a larger granny if it'll serve your needs. Unless you're often using the granny with your larger cassette cogs, you won't lose anything and it'll offer two benefits.

    The larger diameter will improve clearance, reducing the chainslap a bit. And you'll be mating it with larger cogs in back to achieve the same ratios, thus reducing the tendancy to ride cross chained.
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  11. #11
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    Another alternative is going to a larger granny

    Agreed. You can also try screwing in the b-tension screw a tad (I don't know if it will angle the chain down enough - but worth a try). Of course don't go too much that it will compromise the shifting
    Last edited by cort; 04-06-2009 at 07:09 AM.

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