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  1. #1
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    Bottom Bracket Loose

    I was told my cranks can fall off in the middle of my ride if I don't tighten the bottom bracket. I believe they were talking about how threads were showing. I am not exactly sure what the bottom bracket looks like or is, so I need some help. It's on my road bike I don't know if that makes a difference.

    What do I need to do and/or buy to fix it?
    Thanks


    Bottom Bracket Loose-img_20150522_154030.jpgBottom Bracket Loose-img_20150522_154039.jpgBottom Bracket Loose-img_20150522_154052.jpgBottom Bracket Loose-img_20150522_154059.jpg

    Bottom Bracket Loose-img_20150522_154109.jpg

  2. #2
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    It's nor suppose to be like that. The treads are suppose to be flush with the frame. You need to get the crank arm off ( a puller ),that looks like a self puller. Then you need the bottom bracket tool. You tube,Park tools for how to's. A shop could do it in about 10 minutes .The cranks shoudn't fall off ,they are bolt to the bottom bracket axle. But you could damage the cranks.

  3. #3
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    How do I figure out which type of BB tool and crank puller I need? Is the thing with the threads the BB?

  4. #4
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    Quote Originally Posted by El Cheap0 View Post
    How do I figure out which type of BB tool and crank puller I need? Is the thing with the threads the BB?
    8mm hex to get the crank off

    count the number of splines on the inside portion of the threaded part to figure which BB tool.

  5. #5
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    The bottom bracket is the threaded unit shown in the pic. Yours is an internal bearing bottom bracket. It contains the bearings on which the spindle runs and the spindle. The threads shown should be flush with the frame. You need a specific tool to tighten it. It's probably an ISIS requiring this tool Park Tool Co. Park Tool Co.. Count the splines to make sure. You need to remove the crank arm first. 8mm Hex wrench to remove the bolt then a crank puller like this Park Tool Co. Park Tool Co.. You could pull it with steel tire irons but the puller is the better choice for you. The non-drive side is right threaded but the drive side of the bottom bracket is reverse threaded so counter-clockwise to tighten. When you pull the crank (not reverse threaded) make sure to fullly thread the tool in and snug it without going ape, then pull the arm. Once you remove the 8mm hex bolt you'll see threads inside of the hole in the crankarm. Hand tighten the puller then snug with a wrench. Then pull the arm. LBS can probably do it cheaper than buying the tools (though they are relatively cheap by tool standards) unless you want to learn the work and plan on working on it in the future. I've never seen this with a bottom bracket; how'd it happen?

  6. #6
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    Quote Originally Posted by shortnangry View Post
    The bottom bracket is the threaded unit shown in the pic. Yours is an internal bearing bottom bracket. It contains the bearings on which the spindle runs and the spindle. The threads shown should be flush with the frame. You need a specific tool to tighten it. It's probably an ISIS requiring this tool Park Tool Co. Park Tool Co.. Count the splines to make sure. You need to remove the crank arm first. 8mm Hex wrench to remove the bolt then a crank puller like this Park Tool Co. Park Tool Co.. You could pull it with steel tire irons but the puller is the better choice for you. The non-drive side is right threaded but the drive side of the bottom bracket is reverse threaded so counter-clockwise to tighten. When you pull the crank (not reverse threaded) make sure to fullly thread the tool in and snug it without going ape, then pull the arm. Once you remove the 8mm hex bolt you'll see threads inside of the hole in the crankarm. Hand tighten the puller then snug with a wrench. Then pull the arm. LBS can probably do it cheaper than buying the tools (though they are relatively cheap by tool standards) unless you want to learn the work and plan on working on it in the future. I've never seen this with a bottom bracket; how'd it happen?
    You sure the bolt isn't the self-extracting type? Not up on my FSA stuff. Since you seem to know this stuff, what are the odds the bearings/races could be damaged running like this? Should OP consider buying a new BB?

  7. #7
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    You're right, it is self-extracting so crank puller is not needed. There is clearly a retaining ring, that I didn't initially see, meaning it's self-extracting. I'd be more concerned that the threads inside the BB shell are damaged. I wonder if that's why the BB threads are showing in the first place.

  8. #8
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    I guess I need a crank puller now?
    Or is it safe to just use something to pry the crank off?

    Bottom Bracket Loose-brokenbbbolt-.jpg

  9. #9
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    that cap that came off with the bolt should have stayed in there and pulled the arm off. oops. you need a crank pullter tool.

    while you are at it, pull the other arm off, and remove the whole bottom bracket. clean it off, clean all the threads, and reinstall with anti-sieze or Loctite 242, using the appropriate torque (probably about 30 ft/lbs).

  10. #10
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    I removed the nondrive crank first and the bottom bracket. Tons of dirt. (You're right on, it did need 30 ft/lbs).
    Can I not just pry the crank off with brute force though? If not, it's ok b/c I found a crank puller within my budget ($4)

  11. #11
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    Get the crank puller. It is possible to remove using steel tire levers a lot of care and some force, but you should definitely use a crank puller. It'll be 100% easier and you're much less likely to destroy something. Post up once you're done; I'm really curious how BB came loose and what it looks like inside. Check the threads to make sure they're not damaged.

  12. #12
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    the right tool for removing that arm is the cap with the two holes in the edges that you pulled off. that is supposed to stay in the crank arm and pull it off as you undo the bolt. screw it back in tight, maybe with the help of a light thread-locker, and undo that bolt again.

    otherwise, use the right tool. trying to pry the arm off will damage the splines on the inside of the arm.

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