Threading on Pedal Crank

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

Quoted message said:

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

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

Quoted message said:

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:.

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

"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.

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 hidden]> wrote in message
news:[email hidden]...

Quoted message said:

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

John Everett wrote:
<snip>

Quoted message said:

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

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

Quoted message said:

John Everett wrote:
<snip>

Quoted message said:

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.

On Fri, 30 Sep 2005 15:47:56 -0400, Paul Hobson <[email hidden]>

Quoted message said:

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

30 Sep 2005 16:49:40 GMT 'Leo Lichtman said:

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 hidden]
Madison, WI 53711 USA
-----------------------------------------------

Leo Lichtman said:

"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:.

"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.

Leo Lichtman said:

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.