how is a frame's BB shell determined if in spec?

Discussion in 'Cycling Equipment' started by jasong, Mar 23, 2007.

  1. jasong

    jasong New Member

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    I've recently bought a new frame. I can't install 1 new bottom bracket in it, because the shell is distorted. Another one I can get in there, but needing to use more and more force as the BB's ends approach the edges of the shell. When getting that one further in, I can already feel the increase resistance on the spindle, presumable from the frame's shell causing the cartridge to distort and further bind the spingle against the ball bearings inside.

    The manufacturer is implying that this can't be a warranty item. Of course, this means the frame must be replaced, which is very bad for him.

    How is a BB objectively determined to be in spec?

    I can see the disparity as I screw in the drive side of the BB, easily being able to see the gap difference from side to side.

    (later added:

    I didn't mention another part of my test.

    I installed both BBs with no problems (hand tightened all the way) into 2 other blank, new frames. I've never had a BB install problem in 30+ times. Each side of the cartridge BBs install fine, its that there's an inherent tolerance that the shells assume as they get closer to being fully threaded in and need to start gently touching each other. If the BB shell is out, then you simply can't thread each side in, or you must thread them with a lot of force.

    I could get the BBs started by hand into the suspect frame. I really think the shell was either poorly tapped (poor alignment between the opposing sides) or that the shell was tapped and then welded, and was distored during the welding.

    Since I have an older frame by the same mfctr, I tried removing its BB soon after. That BB had even worse problems.

    I know it's a problem in their assembly or QC; but the mfctr is implying that there is no way that a shell can be out of spec. I disagree, but don't have a way others might quantify this.

    )
     
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  2. JASONG! house the yuan? digitize the ti and let us gander.
    why not call the local LBS asking if there's a hozan around. find the
    hozan and hozan the BB. use blue eom loctite liberally when trying the
    BB's again or go for a first try with spoonful pc blaster mixed with
    several drops of valvo synth trans oil. if the BB goes back in,
    cleaner out and redo with the blue lock for permanence.
    wanna restate the chinese ti site?
     
  3. jasong

    jasong New Member

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    Datakoll, I don't think chasing the threads will work. The metals already gone that's been used to tilt it off axis. The threads will be at a slightly different pitch. This is why it seems that screwing up the BB tapping ruins the frame.

    But I'm curious for input,
     
  4. jasong

    jasong New Member

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    Thanks for your reply-

    it's an aluminum frame.

    I think the evidence that:

    one BB won't install, and that another one won't install without warping it's own cartridge and increasing the BB spindle resistance against its ball bearings

    Would you agree? What bike mfctr wouldn't agree?
     
  5. A Muzi

    A Muzi Guest

    jasong wrote:
    > I've recently bought a new frame. I can't install 1 new bottom bracket
    > in it, because the shell is distorted. Another one I can get in there,
    > but needing to use more and more force as the BB's ends approach the
    > edges of the shell. When getting that one further in, I can already
    > feel the increase resistance on the spindle, presumable from the
    > frame's shell causing the cartridge to distort and further bind the
    > spingle against the ball bearings inside.
    >
    > The manufacturer is implying that this can't be a warranty item. Of
    > course, this means the frame must be replaced, which is very bad for
    > him.
    >
    > How is a BB objectively determined to be in spec?
    >
    > I can see the disparity as I screw in the drive side of the BB, easily
    > being able to see the gap difference from side to side.
    >
    > (later added:
    >
    > I didn't mention another part of my test.
    >
    > I installed both BBs with no problems (hand tightened all the way) into
    > 2 other blank, new frames. I've never had a BB install problem in 30+
    > times. Each side of the cartridge BBs install fine, its that there's an
    > inherent tolerance that the shells assume as they get closer to being
    > fully threaded in and need to start gently touching each other. If the
    > BB shell is out, then you simply can't thread each side in, or you must
    > thread them with a lot of force.
    >
    > I could get the BBs started by hand into the suspect frame. I really
    > think the shell was either poorly tapped (poor alignment between the
    > opposing sides) or that the shell was tapped and then welded, and was
    > distored during the welding.
    >
    > Since I have an older frame by the same mfctr, I tried removing its BB
    > soon after. That BB had even worse problems.
    >
    > I know it's a problem in their assembly or QC; but the mfctr is
    > implying that there is no way that a shell can be out of spec. I
    > disagree, but don't have a way others might quantify this.


    Some new frames, especially titanium, use a pre-threaded shell which
    warps during welding. In Titanium this is a real bitch to rectify.

    He owes you either a repair or a replace.
    --
    Andrew Muzi
    www.yellowjersey.org
    Open every day since 1 April, 1971
     
  6. >> Some new frames, especially titanium, use a pre-threaded shell which
    >> warps during welding. In Titanium this is a real bitch to rectify.
    >>
    >>

    >
    > Thanks for your reply-
    >
    > it's an aluminum frame.
    >
    > I think the evidence that:
    >
    > one BB won't install, and that another one won't install without
    > warping it's own cartridge and increasing the BB spindle resistance
    > against its ball bearings
    >
    > Would you agree? What bike mfctr wouldn't agree?


    The questions here would be answered quite readily if you simply bring the
    frame in to a decent bike shop. As yet neither we nor a manufacturer have
    enough information to determine what's going on, and without knowing for
    sure what's going on, it's unreasonable to expect a manufacturer to assume
    that it requires replacement.

    --Mike-- Chain Reaction Bicycles
    www.ChainReactionBicycles.com
     
  7. ddog

    ddog Guest

    On Mar 24, 1:37 am, "Mike Jacoubowsky" <[email protected]> wrote:
    > >> Some new frames, especially titanium, use a pre-threaded shell which
    > >> warps during welding. In Titanium this is a real bitch to rectify.

    >
    > > Thanks for your reply-

    >
    > > it's an aluminum frame.

    >
    > > I think the evidence that:

    >
    > > one BB won't install, and that another one won't install without
    > > warping it's own cartridge and increasing the BB spindle resistance
    > > against its ball bearings

    >
    > > Would you agree? What bike mfctr wouldn't agree?

    >
    > The questions here would be answered quite readily if you simply bring the
    > frame in to a decent bike shop. As yet neither we nor a manufacturer have
    > enough information to determine what's going on, and without knowing for
    > sure what's going on, it's unreasonable to expect a manufacturer to assume
    > that it requires replacement.
    >
    > --Mike-- Chain Reaction Bicycleswww.ChainReactionBicycles.com- Hide quoted text -
    >
    > - Show quoted text -


    If it isn't lugged steel, it ain't real. Anything else is just replace
    and ride, and my LBS has a sign over the counter 'We don't warrant
    Stupidity'
    which is excessively open and subjective imo. As far as I'm concerned,
    Stupidity is not buying lugged (531) steel, but then I
    only have one bike. A friend who has over a dozen nice bikes buys fire
    sales off ebay often so it doesn't matter much
    to him since he rarely pays over a couple of hundred dollars initially
    for a priceless classic, and up to a couple of hundred dollars to
    detail them each.
    He is a perfect bicyle fit with longer legs, so almost any bike size
    fit him perfect with just Nitto bars and Tektro brake levers if not
    equipped with ergo/sti already.

    But if it isn't steel, you better have bought it new and have a good
    relationship with the dealer. A warped BB and stripped BB are the same
    effectively,
    except the dealer will say its stripped, so the customer loses. The
    dealer wins with $300 chinese AL bike 'warranty' claims.

    And people wonder where the phrase 'steel is real' comes from.
     
  8. Lou Holtman

    Lou Holtman Guest

    ddog wrote:

    >
    > If it isn't lugged steel, it ain't real. Anything else is just replace
    > and ride, and my LBS has a sign over the counter 'We don't warrant
    > Stupidity'
    > which is excessively open and subjective imo. As far as I'm concerned,
    > Stupidity is not buying lugged (531) steel, but then I
    > only have one bike. A friend who has over a dozen nice bikes buys fire
    > sales off ebay often so it doesn't matter much
    > to him since he rarely pays over a couple of hundred dollars initially
    > for a priceless classic, and up to a couple of hundred dollars to
    > detail them each.
    > He is a perfect bicyle fit with longer legs, so almost any bike size
    > fit him perfect with just Nitto bars and Tektro brake levers if not
    > equipped with ergo/sti already.
    >
    > But if it isn't steel, you better have bought it new and have a good
    > relationship with the dealer. A warped BB and stripped BB are the same
    > effectively,
    > except the dealer will say its stripped, so the customer loses. The
    > dealer wins with $300 chinese AL bike 'warranty' claims.
    >
    > And people wonder where the phrase 'steel is real' comes from.
    >


    Why is lugged steel only real in this case? What are your experiences
    with aluminum, titanium or carbon frames?

    Lou
    --
    Posted by news://news.nb.nu (http://www.nb.nu)
     
  9. Fixed

    Fixed Guest

    "Lou Holtman" <[email protected]> schreef in bericht
    news:[email protected]
    > ddog wrote:
    >
    >>
    >> If it isn't lugged steel, it ain't real. Anything else is just replace
    >> and ride, and my LBS has a sign over the counter 'We don't warrant
    >> Stupidity'
    >> which is excessively open and subjective imo. As far as I'm concerned,
    >> Stupidity is not buying lugged (531) steel, but then I
    >> only have one bike. A friend who has over a dozen nice bikes buys fire
    >> sales off ebay often so it doesn't matter much
    >> to him since he rarely pays over a couple of hundred dollars initially
    >> for a priceless classic, and up to a couple of hundred dollars to
    >> detail them each.
    >> He is a perfect bicyle fit with longer legs, so almost any bike size
    >> fit him perfect with just Nitto bars and Tektro brake levers if not
    >> equipped with ergo/sti already.
    >>
    >> But if it isn't steel, you better have bought it new and have a good
    >> relationship with the dealer. A warped BB and stripped BB are the same
    >> effectively,
    >> except the dealer will say its stripped, so the customer loses. The
    >> dealer wins with $300 chinese AL bike 'warranty' claims.
    >>
    >> And people wonder where the phrase 'steel is real' comes from.
    >>

    >
    > Why is lugged steel only real in this case? What are your experiences with
    > aluminum, titanium or carbon frames?
    >
    > Lou


    Or filled brazed and tig welded steel frames for that mather?
    For steel is real
    It's a religion Lou so why bother ;-)


    Taeke

    > --
    > Posted by news://news.nb.nu (http://www.nb.nu)
     
  10. right but how can the manufacturer object? the 2 LBS did my frame's BB
    without great cost. if the BB giving problems has an inch plus female
    threads then a fairly low thread percentage plus lock holds the
    cartridge-if the manufacturer won't take it back.
     
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