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Thread: BB Removal

  1. #1
    What It Be ?
    Reputation: ChrisJ's Avatar
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    BB Removal

    I have a 2005 8500. It has an XT cartridge BB. How tight should this thing be in the frame. I tried taking the left side cup out twisting it counterclockwise like the book I have says. It was plastic and a piece cracked off of it. Its staying in the frame. The right side cartridge is real tight twisitng it clockwise. I'm gonna hit it with some PB blaster and let it sit. I had this bike put togther 1 1/2 ago never had it out. Did a muddy ride today and I am cleaning the bike up for a race next week. Let me know.

  2. #2
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    Reputation: Dmytro's Avatar
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    Bottom brackets are typically torqued very well upon installation, so you can expect to exert a lot of force to remove them.

    I believe Park recomends removing the drive train side first, if the non drive train side is plastic (as in your case). This makes sense.

    Personally, I feel Park expresses maintance instructions best: (on this topic and in general)
    http://www.parktool.com/repair/readhowto.asp?id=94

  3. #3
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    Reputation: Speedub.Nate's Avatar
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    50 ft-lbs of torque is the spec, but who knows what it was installed with. I've had some factory assembled frames with bottom brackets so loose I could unscrew them by hand, but yours sounds as if it was built with a little more care.

    Here's what I recommend to hold the tool securely to the BB cup or adapter for "cracking" it during removal: a quick release skewer!

    As Bloodfist suggested in his reply, you can relieve pressure on the plastic adapter by releasing the cartridge side first. However, if the plastic adapter is still stuck, loosely reinstall the cartridge and use the QR techinque -- it'll give you a positive connection that can't possibly slip and do further damage to the splines.



    speedub.nate
    MTBR Hiatus UFN

  4. #4
    No Fear!
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    Ok i have 2 BB that are tottaly stuck to the frames i have one newer square taper thats on a DDG and a really old square taper one with plastic cups which is on a old Marin,

    I have tried 30 times with 10 different people to get BB off the DDG but its not moving a single bit i actually broke my finger trying to remove it its that stuck,I have had it on a table vice where we was trying to turn the frame while the tool is hooked to the vice but it did not bug a bit
    I have tried both driveside and non-driveside but its not moving(SOMEONE FORGOT TO PUT GREASE ON THE BB )

    I dont want to take the frame to the shop as i want to conquer this myself.

    Any help please?

    Whats that tool there

  5. #5
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    I'll try that gotta pick up a socket from Lowes. No thread Hi-Jacking.

  6. #6
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    There are proably several things going on in there.

    1 Galling of the materials. This means you will have to strip some of the material from the shell on to the bracket.

    2 Corrosion can help with penetrating oil.

    3 Foreign material dirt in threads.

    So:

    Step 1:
    Long soak (days) in penetrating oil. Red automotive tranny oil seems to cut and lubricate the best. Break up dirt and corrosion and lubricate.

    Step two:

    Heat I guess that the bottom bracket is aluminim and so is the frame. If not consider the thermal expansion. Aluminium as an aging temp of 165 C. So your okay to heat to 100 C. Using steam or hot water. This thins the penetrant and and may help a little with the galling. Unequal heating may move it slightly (microns) but enough to help break the gall.

    Step 3 another penetrant soak.

    Step 4 heat again.

    Step 5 apply correct well fitted impact socket or equivalent.

    Step 6 apply sharp blows in the correct way (impact wrench or hammer wrench).

    Step 7 done right you should be able to break the socket or free the bracket.

    Most of the above is adapted from motorcycle stuff.

    I cant emphasis that the set-up is critical. you only have two real good chances.

    Last trick drill it out (use lefthanded twist drill (opposite handed twist drill). Usually the heat and vibration will break it free before you really drill to far.

  7. #7
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    It came out little PB Blaster action

  8. #8
    No Fear!
    Reputation: Imperial's Avatar
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    Thanks for the response Jeff will give it all that a try and see if i can get the bloody thing off

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