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  1. #1
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    Chumba Swing Arm Pivot

    I have been thinking about buying an XCL. However, I am a little skepticle of the swing arm pivot (chainstay pivot). I see two seperate pivot pins screwed into the frame on each side of the frame through the sealed bearings.

    I have owned an Intense Tracer for years (a great bike with a similar rear triangle to Chumbas), but the Tracer's swing arm pivot bearings (roughly the same size of Chumba's) always developes slop, what I think is a little prematurely. The Tracer has the small difference of a single pivot axel at the swing link instead of two like Chumba (which in my own mind would be stiffer that the two pivot pin design).

    Should I be concerned? Any wear issues out there someone will tell me about?

    Thanks

  2. #2
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    No need for concern now. Some of the `07 taiwanese frames (and I mean some, NOT ALL) had some issues with pivot bolts backing out but that has been resolved.

    FYI.. you can get a US-made XCL if you so desire.. call Chumba and talk to them.

  3. #3
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    I've been on my XCL for a year now with no indications of slop, it's as solid as the day I got it. The one time I did have any noticable flex was when the old style pivot bolt broke (which was quickly remedied by Chumba).

    Given the design, I don't think that pivot would be prone to developing slop unless an actual bearing gave way or as mentioned before, a bolt backed out or broke.

  4. #4
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    Chumba uses Enduro bearings in all their pivots and those seem to hold up really well. And even if they do develop some slop over the years, replacement bearings are only $4-5 each I believe.

    If you're handy with tools, you can press the bearings in and out yourself. Here's my bearing tool - a little bit of leftover steerer tube, a threaded rod, washers and some nuts.


  5. #5
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    Thanks for the pic. This may seem technical, and I hope this makes sense: Does the swingarm pivot on a single thru axel at the bottom bracket, or are there two seperate pivot pins on each side of the pivot?

  6. #6
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    Quote Originally Posted by Pisgah
    Thanks for the pic. This may seem technical, and I hope this makes sense: Does the swingarm pivot on a single thru axel at the bottom bracket, or are there two seperate pivot pins on each side of the pivot?
    There are 2 bearings and 2 bolts for the BB pivot, so two separate pivot points.

    Edited: Thanks Ricky D
    Last edited by dubjay; 10-01-2008 at 03:26 PM.

  7. #7
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    Just to clarify, it looks like dubjay is referencing an EVO. The OP mentioned the XCL which has only two bearings at the chainstay/BB pivot, one on each side.

  8. #8
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    Quote Originally Posted by Ricky D
    Just to clarify, it looks like dubjay is referencing an EVO. The OP mentioned the XCL which has only two bearings at the chainstay/BB pivot, one on each side.
    Oops, that is correct. Two bearings only. Even the EVO has two bearings at the BB pivot. Not sure what I was thinking.

  9. #9
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    Pisgah, Here's a pic of the pivot area you're asking about. This is actually a EVO that dirtdad put together but it's setup almost exactly like the XCL. The bolts go through the bearings and actually thread into the chainstay. This is a good thing as opposed to threading into the frame as some bike manufacturers have been known to do.


  10. #10
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    Thanks to all for the info.

    Pisgah

  11. #11
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    Quote Originally Posted by Ricky D
    Pisgah, Here's a pic of the pivot area you're asking about. This is actually a EVO that dirtdad put together but it's setup almost exactly like the XCL. The bolts go through the bearings and actually thread into the chainstay. This is a good thing as opposed to threading into the frame as some bike manufacturers have been known to do.

    Talk about stiff!!!

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