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  1. #1
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    Trouble Replacing Sram GXP BB on TruvAtiv Crank

    2007 Specialized Enduro Elite
    2x9 (w/ Bashguard) TruvAtiv Stylo Crank
    SRAM GXP BB (2007?)

    This whole scenario started with me trying to remove my Blackspire chain guide. In order to do this I had to remove my crank, which I have personally never done before. First I removed the left crank arm and chain. Then I tried to slide the right drive side crank out of the BB. It was stuck. I tapped slightly with a rubber mallet and got the splines flush with the left side of my BB. The Crank was stuck again. I could not tap it out. I removed the left BB shell (still could not remove crank). I removed the driveside BB shell and took it off with the crank.

    This is when I noticed my BB plastic housing was cracked. There seems to be some type of metal coupling/spacer holding the driveside of the BB to the spindle.

    I then went to my LBS. They have not seen this metal coupling/spacer before. We called Specialized... they do not know what the coupling/spacer is. We tried calling SRAM, but they were closed for the day.

    In order to remove this coupling/spacer we clamped it in a vice and hammered off the spindle with a rubber mallet (The coupling had to come off to remove the broken BB).

    My question is what is this coupling/spacer? Have any of you seen this before? Why is it there? Can I get a new one ordered from somewhere?

    Here are some pictures.
    The coupling/spacer is set on the crank, it was set further in, totally covering the splines
    (**PHOTO EDIT: Below is correct orientation. "Spacer" Lip is toward the inside as pictured below)




    (**Photo Edit**)




    Thanks for your help, and sorry for the long description.
    ~Kirby
    Last edited by mkirby258; 03-21-2013 at 05:54 AM.

  2. #2
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    Trouble Replacing Sram GXP BB on TruvAtiv Crank

    Haven't seen that spacer before either. Here is what one of mine looks like...

    Trouble Replacing Sram GXP BB on TruvAtiv Crank-imageuploadedbytapatalk1363830470.392641.jpg
    Trouble Replacing Sram GXP BB on TruvAtiv Crank-imageuploadedbytapatalk1363830547.054495.jpg
    【ツ】 eDub 【ツ】

  3. #3
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    Never seen that happen before; that is the step-down for the bearing on the left-hand side, methinks. It it press fit into the bearing, and should never have come off like that. Was there corrosion on the crank or bearing? Any big hits to the crank (botched jump, etc)?

  4. #4
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    Is it the inner bearing race from the non drive side cup? Was the BB a sram/truvative branded unit? All of those do not use a spacer to shim down the non drive side, but many of the aftermarket versions do.

  5. #5
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    Quote Originally Posted by wschruba View Post
    Never seen that happen before; that is the step-down for the bearing on the left-hand side, methinks. It it press fit into the bearing, and should never have come off like that. Was there corrosion on the crank or bearing? Any big hits to the crank (botched jump, etc)?
    No corrosion on the crank, & no extra ordinary hits to the crank. Possible press fit bearing, but no one seems to know. Doing some more digging

    Quote Originally Posted by customfab View Post
    Is it the inner bearing race from the non drive side cup? Was the BB a sram/truvative branded unit? All of those do not use a spacer to shim down the non drive side, but many of the aftermarket versions do.
    I am not too familiar with BB anatomy, so not quite sure if it is the "inner bearing race"? The BB is not stamped SRAM. The only names on it show "GXP" & "XR". I assumed GXP was SRAM.

    The mystery continues!
    ~Kirby
    Last edited by mkirby258; 03-21-2013 at 04:59 AM.

  6. #6
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    Did you get the bike new or used and are those the Oem cranks? The reason I ask is I think someone put GXP cranks in a shimano BB with a adapter. The GXP BB has different size inner holes on each side and the Shimano has the same size inner holes on each side. I would get a new BB for GXP and that should have the parts you need. If the BB you have has the inner holes the same size it was designed for Shimano and someone added the adapter.

  7. #7
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    Quote Originally Posted by mkirby258 View Post
    I am not too familiar with BB anatomy, so not quite sure if it is the "inner bearing race"? The BB is not stamped SRAM. The only names on it show "GXP" & "XR". I assumed GXP was SRAM.

    The mystery continues!
    ~Kirby
    If you look at the non drive bearing as it sits, are the balls visiable and wold they ride directly on the crank spindle?

    GXP is SRAM's trade name for their outboard bearing system. As far as I know nobody else stamps their GXP compatible bottom bracket with GXP. That bit does look like the shim that's used to run a shimano style BB with GXP cranks, but if your BB is stamped GXP it wouldn't have gone together with that in there.

  8. #8
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    The mystery has been solved! It is part of the non-drive side BB (usually pressed into the bearing). It must have bonded to the spindle and came off when the spindle was tapped out of the non-drive side BB.

    Talked with SRAM. Then shortly after, I received the new BB in the mail. Close comparison between the new & old revealed the truth.

    Thanks for all your help! It had me stumped for a while there!

    ~Kirby

    PS: the new one will definitely be appropriately greased & torqued

    ~Kirby

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