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  1. #1
    Dad
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    Bottom Bracket Adapter...? HELP!

    Hi

    Just bought an FSA K-Force Ultralight crankset and bottom bracket (BB30) and was hoping to replace the XT cranks/BB on my 2011 Norco Team Carbon, which uses a Shimano SM-BB90-A. Yes, I feel a bit stupid that they are obviously not compatible and a simple replacement is not an option.

    So...

    My question is this; can I buy an adapter that screws into the frame's bottom bracket housing and accepts the bearings/crank of my FSA K-Force?

    I'd *REALLY* like to fix this, or I am stuck with an incredibly expensive, gorgeous and useless FSA crank/BB set.

    Thanks!

  2. #2
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by Dad View Post
    Hi

    Just bought an FSA K-Force Ultralight crankset and bottom bracket (BB30) and was hoping to replace the XT cranks/BB on my 2011 Norco Team Carbon, which uses a Shimano SM-BB90-A. Yes, I feel a bit stupid that they are obviously not compatible and a simple replacement is not an option.

    So...

    My question is this; can I buy an adapter that screws into the frame's bottom bracket housing and accepts the bearings/crank of my FSA K-Force?

    I'd *REALLY* like to fix this, or I am stuck with an incredibly expensive, gorgeous and useless FSA crank/BB set.

    Thanks!
    No adaptor. You bought the wrong crankset.
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  3. #3
    Dad
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    But Norco calls my frame BB30...?


  4. #4
    Nouveau Retrogrouch SuperModerator
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    You just said you have a BB90 bottom bracket. They do not fit in a BB30 frame.

    If it is a BB30 frame, you do not need adaptors for the new crank.
    mtbtires.com
    The trouble with common sense is it is no longer common

  5. #5
    Dad
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    Confused

    I don't know what kind of BB I have; I'm confused. The frame is described at the link I provided as being BB30 (which is why I thought I'd be ok buying a BB30 crankset);

    Team Carbon Mountain Frame Only Norco Bikes

    Why would Norco describe my frame as being BB30 if it's not? Or did they make some 2011 Team Carbons that were not BB30?

    The cartridge I find in my frame, however, is a Shimano SM-BB90-A.

    The cartridge cup that screws into the frame houses the bearing. Can I buy an adaptor cup (larger than the current one) that screws into the frame to accommodate press fit BB30 bearings? If so, then all is well. If not, then I'm buggered.

    I don't know much about BB standards (apparently), but a bit of internet research demonstrates that a lot of people are obviously confused and even the experts seem to disagree on a lot of compatibility issues.

  6. #6
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by Dad View Post
    I don't know what kind of BB I have; I'm confused. The frame is described at the link I provided as being BB30 (which is why I thought I'd be ok buying a BB30 crankset);

    Team Carbon Mountain Frame Only Norco Bikes

    Why would Norco describe my frame as being BB30 if it's not? Or did they make some 2011 Team Carbons that were not BB30?

    The cartridge I find in my frame, however, is a Shimano SM-BB90-A.

    The cartridge cup that screws into the frame houses the bearing. Can I buy an adaptor cup (larger than the current one) that screws into the frame to accommodate press fit BB30 bearings? If so, then all is well. If not, then I'm buggered.

    I don't know much about BB standards (apparently), but a bit of internet research demonstrates that a lot of people are obviously confused and even the experts seem to disagree on a lot of compatibility issues.
    The BB90 is press fit, not threaded.

    BB30 is either press fit or direct fit. No threads.

    I have heard of BB90 bottom brackets being installed in BB30 (not press fit BB30) frames with spacers, but it is not an approved fitment and may damage the frame's bearing seats.
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  7. #7
    Dad
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    There may be hope yet...

    Been doing some homework on BB standards...

    The dimensions of my BB suggest it *IS* BB30 (getting a bit excited now!). It's 68 mm wide and the threaded bit that the Shimano Hollowtech cups screw into is 42 mm in diam (also BB standard).

    So my question is this; is it common to find a threaded insert in a BB30 frame instead of pressfit bearings so a Shimano Hollowtech crankset can be used? If so, 'all' I have to do is extract the threaded inserts so I can then press in my bearings?

  8. #8
    Dad
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    By the way, despite the Shimano cartridge being numbered SM-BB90-A, I don't think this necessarily means it's BB90...? BB90, as I understand, refers to the width of the frame at the BB, and my frame is nothing like that. It's 68mm, suggesting BB30.

  9. #9
    turtles make me hot
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    I'm building my wife a Salsa Spearfish that has BB30. I wanted to use a Shimano XT crankset. I didn't like the adapters and the BB30. I found this:
    Praxis Works | Conversion Kit

    Bought it, installed it and installed the XT crankset. It all works mint.
    I like turtles

  10. #10
    Nouveau Retrogrouch SuperModerator
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    Quote Originally Posted by Dad View Post
    Been doing some homework on BB standards...

    The dimensions of my BB suggest it *IS* BB30 (getting a bit excited now!). It's 68 mm wide and the threaded bit that the Shimano Hollowtech cups screw into is 42 mm in diam (also BB standard).

    So my question is this; is it common to find a threaded insert in a BB30 frame instead of pressfit bearings so a Shimano Hollowtech crankset can be used? If so, 'all' I have to do is extract the threaded inserts so I can then press in my bearings?
    I think you need to take the frame back to whoever installed the cranks.

    There are threaded adaptors for BB30 frames to use standard threaded BBs. If you have one of these installed you will also have regular external bearing cups on your bike.

    Removing the adaptor is not easy, if possible.
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  11. #11
    Dad
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    Ah-HA!

    Took a lot of digging, but here's the answer for anyone interested;

    Removing the adapter from a Carbon frame BB30.

    It IS a BB30, but has threaded adapters. If I want to use 'proper' BB30 press fit bearings, the threaded adapters need to be removed. But by someone with more confidence and tools than I.

    So, it's off to the LBS to find someone competent.

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