Threading on Pedal Crank

Discussion in 'Cycling Equipment' started by [email protected], Sep 30, 2005.

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  2. David Green

    David Green Guest

    Hi Jim, you should definitely have you stripped out pedal bosses
    evaluated in person by a professional. If the striping isnt too bad,
    i.e., the inner diameter of the treads hasn't been significantly
    wallowed out, you can very likely get away with simply having your
    cranks "tapped," or re-treaded. If it looks like there's not enough
    material left for the tap to get a good bite one, then unfortunitely,
    you're really in rew crank-arm territory. It's hard to tell definitively
    by the looks of your pictures, but I think that since you appear to
    still have good threads on the remaining threads, I'd say to just have
    it tapped, in order to get the treads realligned, and then, even if the
    stripped part wont grip the pedal's spindle, the other half should
    provide a strong enough hold for you. Just be sure to check the pedal
    regularly to make sure it's tight - a regular measure anyway.

    -David

    --
    "Follow your bliss."
    - Joseph Campbell
     
  3. John Everett

    John Everett Guest

    On 30 Sep 2005 07:22:06 -0700, [email protected] wrote:

    >I am unable to get the left pedal into the crank (terminology??)
    >because I screwed up the threading.
    >
    >Pic here: http://img305.imageshack.us/my.php?image=dsc000352fw.jpg
    >and here: http://img305.imageshack.us/my.php?image=dsc000367rq.jpg
    >
    >What should I do: (a) get new crank(s)
    > (b) go to shop and get crank rethreaded.
    >Is there some kind of yoke I can buy to rethread it?
    >
    >any ideas?


    First find a shop that has crank/pedal taps. These are 9/16" x 20, but
    unfortunately the left crank has a left hand thread, making these taps
    hard to come by. Have the threads chased from the "other side", the
    inside surface of the crank. This will ensure that the tap is
    correctly aligned when it starts to cut into the damaged area.

    From the pictures the crank looks salvageable.

    BTW, I just checked the Grainger web site and 9/16 x 20 taps may be
    rarer that I thought. They list no taps in this size. 9/16 x 18 comes
    closest. Third Hand/Loose Screws used to (IIRC) list crank taps, but I
    just checked their site and can't find them.



    jeverett3<AT>earthlink<DOT>net http://home.earthlink.net/~jeverett3
     
  4. Leo Lichtman

    Leo Lichtman Guest

    I have had success by simply threading the pedal in from the back (and then
    removing it and threading in from the front ;-)
     
  5. Paul Hobson

    Paul Hobson Guest

    [email protected] wrote:
    > I am unable to get the left pedal into the crank (terminology??)
    > because I screwed up the threading.
    >
    > Pic here: http://img305.imageshack.us/my.php?image=dsc000352fw.jpg
    > and here: http://img305.imageshack.us/my.php?image=dsc000367rq.jpg
    >
    > What should I do: (a) get new crank(s)
    > (b) go to shop and get crank rethreaded.
    > Is there some kind of yoke I can buy to rethread it?
    >
    > any ideas?
    >
    > thanks in advance
    >
    > JimBob
    >


    If you are in need of getting a new crank, I seem to remember the dude
    at REI asking me if I needed both sides. It's been a while, but it
    really seems that way. maybe you can get away with just getting the
    non-drive side (cheaper) crank. YMMV simply b/c I was getting the
    cheapest possible cranks.

    \\paul
    --
    Paul M. Hobson
    Georgia Institute of Technology
    ..:change the words to numbers
    if you want to reply to me:.
     
  6. Llatikcuf

    Llatikcuf Guest

    I didn't tighten down a pedal enough and it flopped around and then
    fell out while I was riding. The threads were gone. I could push the
    pedal in and out of the hole with no resistance. I Took it to my LBS
    and he actually put new threads in. I believe its called helicoil. They
    actually thread a bigger hole and then put in a threaded insert. It has
    worked for about 7 years, no problems. Might want to ask about it.

    -Nate
     
  7. Leo Lichtman

    Leo Lichtman Guest

    "Llatikcuf" wrote: (clip) I Took it to my LBS and he actually put new
    threads in. I believe its called helicoil. (clip)
    ^^^^^^^^^^^^^^^^^
    I have used a great many Helicoils, and I swear by them. I didn't know
    there was one available to match pedal threads, though. The repaired thread
    is probably better than new, since the replacement thread is made of
    stainless steel. I watched a mechanic use one to fix stripped threads on my
    VW cylinder head, using a mirror. I was impressed. The thing is, stainless
    threads are MUCH less prone to gall or strip out than aluminum.
     
  8. me

    me Guest

    A good shop can put a Helicoil in for you. A-OK. Many tandem cranks are
    made this way, by modifying RH cranks into LH cranks. On the net try
    someone like Tandems Unlimited.

    Jeffrey


    <[email protected]> wrote in message
    news:[email protected]
    >I am unable to get the left pedal into the crank (terminology??)
    > because I screwed up the threading.
    >
    > Pic here: http://img305.imageshack.us/my.php?image=dsc000352fw.jpg
    > and here: http://img305.imageshack.us/my.php?image=dsc000367rq.jpg
    >
    > What should I do: (a) get new crank(s)
    > (b) go to shop and get crank rethreaded.
    > Is there some kind of yoke I can buy to rethread it?
    >
    > any ideas?
    >
    > thanks in advance
    >
    > JimBob
    >
     
  9. JeffWills

    JeffWills Guest

    John Everett wrote:
    <snip>
    > BTW, I just checked the Grainger web site and 9/16 x 20 taps may be
    > rarer that I thought. They list no taps in this size. 9/16 x 18 comes
    > closest. Third Hand/Loose Screws used to (IIRC) list crank taps, but I
    > just checked their site and can't find them.
    >


    Bike Tools Etc. has 'em:
    http://www.biketoolsetc.com/index.cgi?&d=single&item_id=VR-41E

    Jeff
     
  10. Bob

    Bob Guest

    On 30 Sep 2005 21:10:12 -0700, "JeffWills" <[email protected]>
    wrote:

    >
    >John Everett wrote:
    ><snip>
    >> BTW, I just checked the Grainger web site and 9/16 x 20 taps may be
    >> rarer that I thought. They list no taps in this size. 9/16 x 18 comes
    >> closest. Third Hand/Loose Screws used to (IIRC) list crank taps, but I
    >> just checked their site and can't find them.
    >>

    >
    >Bike Tools Etc. has 'em:
    >http://www.biketoolsetc.com/index.cgi?&d=single&item_id=VR-41E
    >
    >Jeff


    or http://www.mcmaster.com/ Search for tap, drill your way down. These
    folks sell everything mechanical and ship any quantity.
     
  11. On Fri, 30 Sep 2005 15:47:56 -0400, Paul Hobson <[email protected]>
    wrote:

    >If you are in need of getting a new crank, I seem to remember the dude
    >at REI asking me if I needed both sides. It's been a while, but it
    >really seems that way. maybe you can get away with just getting the
    >non-drive side (cheaper) crank. YMMV simply b/c I was getting the
    >cheapest possible cranks.


    Left cranks tend to be pretty damn cheap, yeah. Whereas the right crank
    can be well over half to threequarters of an entire crankset, with both
    cranks and the chainrings.

    Jasper
     
  12. Jim Adney

    Jim Adney Guest

    On Fri, 30 Sep 2005 16:49:40 GMT "Leo Lichtman"
    <[email protected]> wrote:

    >I have had success by simply threading the pedal in from the back (and then
    >removing it and threading in from the front ;-)


    This would be my suggestion. It's something that you already have the
    tool for, plus it does not remove any metal - it just pushes the old
    metal back into place, resulting in a stronger thread. Even if you end
    up running a tap thru it (definitely also from the inside out) you
    should run a pedal in there first.

    -
    -----------------------------------------------
    Jim Adney [email protected]
    Madison, WI 53711 USA
    -----------------------------------------------
     
  13. Paul Hobson

    Paul Hobson Guest

    Leo Lichtman wrote:
    > "Llatikcuf" wrote: (clip) I Took it to my LBS and he actually put new
    > threads in. I believe its called helicoil. (clip)
    > ^^^^^^^^^^^^^^^^^
    > I have used a great many Helicoils, and I swear by them. I didn't know
    > there was one available to match pedal threads, though. The repaired thread
    > is probably better than new, since the replacement thread is made of
    > stainless steel. I watched a mechanic use one to fix stripped threads on my
    > VW cylinder head, using a mirror. I was impressed. The thing is, stainless
    > threads are MUCH less prone to gall or strip out than aluminum.
    >
    >


    REI installed one on my girlfriend's bike, which had been crash and the
    pedal had been ripped out during its life with the previous owner.

    BIG NOTE: some shopps refused to do it as it was a liability or ust a
    pain in their ass.

    --
    Paul M. Hobson
    Georgia Institute of Technology
    ..:change the words to numbers
    if you want to reply to me:.
     
  14. Leo Lichtman

    Leo Lichtman Guest

    "Paul Hobson" wrote: (clip) BIG NOTE: some shopps refused to do it as it
    was a liability or ust a pain in their ass.
    ^^^^^^^^^^^^^^
    Don't you HATE it when they do that? Their so-called concern about
    liability translates in my mind to a concern for maximizing profit. As I
    said earlier, an aluminum crank with a Helicoil is stronger and more durable
    than new.
     
  15. Bob

    Bob Guest

    On Sun, 02 Oct 2005 22:37:40 GMT, "Leo Lichtman"
    <[email protected]> wrote:

    >Don't you HATE it when they do that? Their so-called concern about
    >liability translates in my mind to a concern for maximizing profit. As I
    >said earlier, an aluminum crank with a Helicoil is stronger and more durable
    >than new.


    It's takes a real mechanic to install a helicoil - people who replace
    parts for a living don't have the equipment or skills.
     
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