Remedying crossthreading?

Discussion in 'Recumbent bicycles' started by Mikael Seierup, Feb 26, 2004.

  1. Due to paint I munged the first few mm of the thread for the rear derailleur. Threaded hole on the
    frame I mean. Any way to correct it?

    /Mikael
     
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  2. Bryan Ball

    Bryan Ball Guest

    Sometimes it can be as easy as threading the bolt in from the backside. If the bolt material is
    stronger than the drop-out material this can sometimes "re-tap" it.

    "Mikael Seierup" <[email protected]> wrote in message news:[email protected]
    berlin.de...
    > Due to paint I munged the first few mm of the thread for the rear
    derailleur.
    > Threaded hole on the frame I mean. Any way to correct it?
    >
    > /Mikael

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    Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com).
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  3. Cletus Lee

    Cletus Lee Guest

    In article <[email protected]>, [email protected] says...
    > Due to paint I munged the first few mm of the thread for the rear derailleur. Threaded hole on the
    > frame I mean. Any way to correct it?

    If you can't re-tap the threads using Bryan's suggestion, There are inserts that can be fitted
    into the old hole. I think the process is to drill out the derailleur hole. press in a derailleur
    sized insert.

    --

    Cletus D. Lee Bacchetta Giro Lightning Voyager http://www.clee.org
    - Bellaire, TX USA -
     
  4. "Cletus Lee" skrev...
    > If you can't re-tap the threads using Bryan's suggestion, There are inserts that can be fitted
    into
    > the old hole. I think the process is to drill out the derailleur hole. press in a derailleur
    > sized insert.

    For now I'll let the LBS worry about it, but if he fails I'll try the insert. Thanks. The other
    side approach didn't work alas. Just typical it happens five days before someones hopefully
    buying it. :)

    /Mikael
     
  5. In article <[email protected]>, Mikael Seierup says...
    >
    >
    >"Cletus Lee" skrev...
    >>If you can't re-tap the threads using Bryan's suggestion, There are inserts that can be fitted
    >into
    >>the old hole. I think the process is to drill out the derailleur hole. press in a derailleur
    >>sized insert.
    >
    >For now I'll let the LBS worry about it, but if he fails I'll try the insert. Thanks. The other
    >side approach didn't work alas. Just typical it happens five days before someones hopefully
    >buying it. :)

    It may not be worth buying for just this one instance, but what you need is a 10 mm by 1 mm metric
    thread chaser (or tap) for the derailleur hanger (about $5 at www.biketoolssetc.com). I have bent
    the derailleur hanger on a number of bikes, so I keep a derailleur hanger tool and a thread chaser
    in my shop. Your LBS will have the chaser.

    Steve Christensen Midland, MI
     
  6. Tom Blum

    Tom Blum Guest

    Mikey,

    Best way: buy a tap with the correct thread. run it through the hole from the other end.

    Cheapie sometmes works way (Don't quote me, I'll deny it!) Run a bolt with the correct thread thru
    from the other side. If that doesn't work, sometimes, you can grind a flat onto the thread and use
    that as a one time tap.

    Good Luck,

    Tom "Mikael Seierup" <[email protected]> wrote in message news:[email protected]
    berlin.de...
    > Due to paint I munged the first few mm of the thread for the rear
    derailleur.
    > Threaded hole on the frame I mean. Any way to correct it?
    >
    > /Mikael
     
  7. "Steve Christensen" skrev

    > It may not be worth buying for just this one instance, but what you need is a 10 mm by 1 mm metric
    > thread chaser (or tap) for the derailleur hanger (about $5 at www.biketoolssetc.com). I have bent
    > the derailleur hanger on a number of bikes, so I keep a derailleur hanger tool and a thread chaser
    > in my shop. Your LBS will have the chaser.

    Yup, he fixed it for me. I will of course inform the prospective buyer that the thread might be a
    bit munged so too much removing and refitting of the derailleur is not advisable. But at 2300 DKK or
    300 euro for whats basically a new frame with new albeit cheap components you can't get everything.

    Cheers Mikael
     
  8. Dan Burkhart

    Dan Burkhart New Member

    Joined:
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    I don't know if it is common practice in the bicycle industry to use Heli-coils to replace ruined threads, but if they are good enough to hold a heavy duty truck transmission in place, I think they might be worth a try.
    Your local machine shop would be the place to find out.
     
  9. Dan Burkhart wrote:

    > I don't know if it is common practice in the bicycle industry to use Heli-coils to replace ruined
    > threads, but if they are good enough to hold a heavy duty truck transmission in place, I think
    > they might be worth a try. Your local machine shop would be the place to find out.

    When a rogue plastic bag demolished the rear derailleur and hanger on thread on Mrs Larrington's
    Kingcycle, this was the fix that Bikefix applied, so I imagine that a helicoil with that particular
    threading is fairly easy to get hold of.

    --

    Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
    ===========================================================
    Editor - British Human Power Club Newsletter
    http://www.bhpc.org.uk/
    ===========================================================
     
  10. Freewheeling

    Freewheeling Guest

    My auto and bike mechanic friends used to call it a
    "helicoil."

    --
    --Scott
    "Cletus Lee" <[email protected]> wrote in message
    news:[email protected]...
    > In article <[email protected]>,
    [email protected] says...
    > > Due to paint I munged the first few mm of the thread for the rear
    derailleur.
    > > Threaded hole on the frame I mean. Any way to correct it?
    >
    > If you can't re-tap the threads using Bryan's suggestion, There are
    inserts that can be fitted into
    > the old hole. I think the process is to drill out the derailleur hole.
    press in a derailleur sized
    > insert.
    >
    >
    > --
    >
    > Cletus D. Lee
    > Bacchetta Giro
    > Lightning Voyager
    > http://www.clee.org
    > - Bellaire, TX USA -
     
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