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  1. #1
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    bottom bracket fixed cup comming loose on me....

    so i have a older bianchi sport sx i picked up this spring. The bb left drive fixed cup has come loose a few times. The threads are still good from what i can see. My lack of being ablet o get it tight with a large adjustable wrench on the small flats is likely the problem. Turning the cranks forward is also the way the cup loosens. I believe this is italian threading. Even though this bianchi was probably made in japan and has tange superset bianchi tubing......would it still have italian threading because of the bianchi name? The frame is certainly not an itailian frame from what i can tell.

    That said.....should i invest in the park bb tool and try that? Invest in a sealed bb and go that route? try out sheldons grade8 bolt and washer trick in reverse using my large breaker bar? I have read that some users have a fixed cup wrench.......put it over the flats.....a bolt through the hole and run a washer bigger than the face of the bb face which when tightend down a bit will hold the wrench directly on the flats a bit better for when you are applying massive force to get it tight. It keeps it from slipping off.

  2. #2
    Insane Bicycle Mechanic Jeff Wills's Avatar
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    Quote Originally Posted by scale View Post
    so i have a older bianchi sport sx i picked up this spring. The bb left drive fixed cup has come loose a few times. The threads are still good from what i can see. My lack of being ablet o get it tight with a large adjustable wrench on the small flats is likely the problem. Turning the cranks forward is also the way the cup loosens. I believe this is italian threading. Even though this bianchi was probably made in japan and has tange superset bianchi tubing......would it still have italian threading because of the bianchi name? The frame is certainly not an itailian frame from what i can tell.

    That said.....should i invest in the park bb tool and try that? Invest in a sealed bb and go that route? try out sheldons grade8 bolt and washer trick in reverse using my large breaker bar? I have read that some users have a fixed cup wrench.......put it over the flats.....a bolt through the hole and run a washer bigger than the face of the bb face which when tightend down a bit will hold the wrench directly on the flats a bit better for when you are applying massive force to get it tight. It keeps it from slipping off.

    If the cup loosens clockwise, then it's left-hand thread and it's English thread. I just sold my 10-year old Bianchi, and it had an English thread BB, too.

    Get the correct tool for your bottom bracket. There's no way you'll get it tight enough with an adjustable wrench. I've always been able to get fixed cups tight enough with a Park HCW-4: http://parktool.com/products/detail....=25&item=HCW-4, held on the cup by hand and banged with a rubber mallet.
    Jeff Wills

    All my bikes.

  3. #3
    Bianchi Goddess Bianchigirll's Avatar
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    Hi scale, what color is your Sport SX and the component group? odds are it is an english BB. I would overhaul it rather than keep tightening it. they call them 'fixed' cups for a reason and just tightening it with an adjustable wrench does not provide nearly enough torque. if you don't have a crank puller or BB tools already I susgest just take it to the shop. that ways if the BB is bad and you replace it with a cartridge you don't have to buy tools you may never use again.

    OH is it Celeste with Sport LX shimano?
    Bianchis '87 Sport SX, '90 Proto (2), '91 Boarala 'cross, '93 Project 3, '88 Trofeo, '86 Volpe, '89 Axis, '79 Mixte, '99 Mega Pro XL Ti, '97 Ti Megatube, , '90 something Vento 603,

    Others but still loved,; '80 RIGI, '80 Batavus Professional, '87 Cornelo, '86 Bertoni (sold), '09 Motobecane SS, '98 Hetchins M.O., '09 K2 Mainframe, '89 Trek 2000, '?? Jane Doe (still on the drawing board), '90ish Haro Escape

  4. #4
    Old fart JohnDThompson's Avatar
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    A Japanese-built Bianchi will be English thread; i.e. the fixed cup will be left hand thread. If you are not willing/able to purchase the tools needed to properly secure your BB cups, take your bike to your LBS to have it serviced.

  5. #5
    Senior Member mazdaspeed's Avatar
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    A fixed cup wrench is like $15-20

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