Can I bring this frame back from the dead?

Discussion in 'Cycling Equipment' started by Dumpster Bike, Nov 18, 2003.

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  1. i came across a jamis mountain bike hardtail frame that looks like it might fit. its a durango SX,
    triple gauge 7005 aluminum with no fork and no damage that i can see, EXCEPT 3/4 of the threads on
    the drive side of the bottom bracket shell are stripped out starting from the outside. i can still
    see the threads but i doubt they will hold a cup.

    barring that there is no other damage (i have yet to check it with frame alignment tools), how may i
    go about fixing these threads, how much will it cost, and is it even worth it cost wise? the frame
    has so far cost me nothing and i have enough parts to build it up, but rechasing threads, messing
    around with helocoils or cutting threads to fit in weird larger bottom brackets sounds like it may
    become expensive real quick. any ideas or experience with this type of thing? is it safe to ride?
    how did this happen initially? thanks!
     
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  2. David

    David Guest

    "Dumpster Bike" <[email protected]> wrote in message
    news:[email protected]...
    > i came across a jamis mountain bike hardtail frame that looks like it might fit. its a durango SX,
    > triple gauge 7005 aluminum with no fork and no damage that i can see, EXCEPT 3/4 of the threads on
    > the drive side of the bottom bracket shell are stripped out starting from the outside. i can still
    > see the threads but i doubt they will hold a cup.
    >
    >
    Here are few solutions people have used for this in the past.
    1. Tap the BB shell for an italian-threaded BB.

    2. I think there are BBs (YST?) that are supposed to work in a stripped BB shell.

    3. Use some kind of filler, and retap the threads.
     
  3. Matt O'Toole

    Matt O'Toole Guest

    "David" <[email protected]> wrote in message
    news:[email protected]...
    >
    > "Dumpster Bike" <[email protected]> wrote in message
    news:[email protected]...
    > > i came across a jamis mountain bike hardtail frame that looks like it might fit. its a durango
    > > SX, triple gauge 7005 aluminum with no fork and no damage that i can see, EXCEPT 3/4 of the
    > > threads on the drive side of the bottom bracket shell are stripped out starting from the
    > > outside. i can still see the threads but i doubt they will hold a cup.
    > >
    > >
    > Here are few solutions people have used for this in the past.
    > 1. Tap the BB shell for an italian-threaded BB.
    >
    > 2. I think there are BBs (YST?) that are supposed to work in a stripped BB
    shell.
    >
    > 3. Use some kind of filler, and retap the threads.

    Sure -- if you have the requisite taps. JB Weld should work fine for this.

    Matt O.
     
  4. Phil Brown

    Phil Brown Guest

    >no damage that i can see, EXCEPT 3/4 of the threads on the drive side of the bottom bracket shell
    >are stripped out starting from the outside. i can still see the threads but i doubt they will
    >hold a cup.

    If you can see threads they may be OK with just a chasing. Phil Brown
     
  5. Dumpster Bike wrote:

    > i came across a jamis mountain bike hardtail frame that looks like it might fit. its a durango SX,
    > triple gauge 7005 aluminum with no fork and no damage that i can see, EXCEPT 3/4 of the threads on
    > the drive side of the bottom bracket shell are stripped out starting from the outside. i can still
    > see the threads but i doubt they will hold a cup.
    >
    > barring that there is no other damage (i have yet to check it with frame alignment tools), how may
    > i go about fixing these threads, how much will it cost, and is it even worth it cost wise? the
    > frame has so far cost me nothing and i have enough parts to build it up, but rechasing threads,
    > messing around with helocoils or cutting threads to fit in weird larger bottom brackets sounds
    > like it may become expensive real quick. any ideas or experience with this type of thing? is it
    > safe to ride? how did this happen initially? thanks!

    Yes - just get a BB designed for stripped threads. They have a lockring on each side and often the
    chainline is adjustable too.
     
  6. J.B. weld? YST? what do these things mean? and i have a friend who does frame work well so retapping
    shouldnt be too big a deal.
     
  7. David

    David Guest

    "Dumpster Bike" <[email protected]> wrote in message
    news:[email protected]...
    > J.B. weld?

    It's an epoxy with added steel. It's the first thing I think of for this sort of thing too, but I'm
    far from an expert, and I'm not sure it's the best choice.

    > YST?

    A brand of BB.

    > what do these things mean? and i have a friend who does frame work well so retapping shouldnt be
    > too big a deal.

    If you tap to Italian threads, or install the BB-for-stripped-shells, you limit your BB/crank
    choices. Filling in and retapping, while not the most promising, gives you the most choices.
     
  8. In article <[email protected]>, [email protected] says...
    >J.B. weld? YST? what do these things mean? and i have a friend who does frame work well so
    > retapping shouldnt be too big a deal.

    Go to an auto parts place and ask for a tube of jb weld. It is some sort of epoxy that can be used
    to repair metal. YST is a brand name. they make bottom brackets, among other stuff.
    ------------
    Alex
     
  9. Papercut

    Papercut Guest

    Someone posted a link a few weeks ago to a threadless BB. Was inexpensive, too. I've also seen
    threadless BBs in some BMX catalogs.
     
  10. On Tue, 18 Nov 2003 21:57:34 +0000, Dumpster Bike wrote:

    > barring that there is no other damage (i have yet to check it with frame alignment tools), how may
    > i go about fixing these threads, how much will it cost, and is it even worth it cost wise? the
    > frame has so far cost me nothing and i have enough parts to build it up, but rechasing threads,
    > messing around with helocoils or cutting threads to fit in weird larger bottom brackets sounds
    > like it may become expensive real quick. any ideas or experience with this type of thing? is it
    > safe to ride? how did this happen initially? thanks!

    It probably happened because the bottom bracket was cross-threaded, and the guy doing it did not
    know what he was doing. Aluminum threads are not all that strong.

    You have several options. You could apply some sort of "liquid metal" goop, or an epoxy resin or
    something, and try to chase the threads through that. If paint is not a problem, you might try
    "alumaloy" which makes great claims for repairs of all sorts with aluminum. The heat needed would
    ruin the paint around there, though.

    But I would try, first, a sturdy Shimano cartridge bottom bracket. They really don't need all the
    threads to be there to hold well (I know this). If that doesn't work, heck, it's less than $20.
    There are a few bottom brackets designed for threadless shells -- held on by a beveled edge.

    You can have a local shop chase the threads to see if some good threads are left.

    Some of these, at least, are worth a try.

    --

    David L. Johnson

    __o | Do not worry about your difficulties in mathematics, I can _`\(,_ | assure you that mine
    are all greater. -- A. Einstein (_)/ (_) |
     
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