Damaged thread

Neil Smith said:

Dear All,
Threaded fork was at a metal who very helpfully managed to remove a
frozen stem. However the thread on the fork seems to have been
damaged. A little filling seems to have helped but the thread is
still blocked. Any suggestions?

Find a local bike builder and give him a fiver to run a die down it would
be my choice.

You can recut a thread with the edge of a very fine half-round file but
the chances of getting it wrong are pretty high. Better to stump up a few
quid and use the right tool for the job.

Tom

Neil Smith said:

Dear All,
Threaded fork was at a metal who very helpfully managed to remove a frozen
stem. However the thread on the fork seems to have been damaged. A little
filling seems to have helped but the thread is still blocked. Any
suggestions?
thanks
Neil

Depends on your tooling abilities. Either take it to a *good* bike shop
who should have the correct die to recut the thread, or take a spare
headset nut, heat it until it glows bright red all over and drop it into
a bath of cold oil to cool rapidly, then bit by bit use it to nibble
down the thread with cutting fluid, carefully checking every ~1/4 ofa
turn that you arent damaging the thread further. Personally I'd go with
the second option, but only because I like a challenge!

In article said:

Neil Smith said:

Threaded fork was at a metal who very helpfully managed to remove a frozen
stem. However the thread on the fork seems to have been damaged. A little
filling seems to have helped but the thread is still blocked. Any
suggestions?

Depends on your tooling abilities. Either take it to a *good* bike shop
who should have the correct die to recut the thread, or take a spare
headset nut, heat it until it glows bright red all over and drop it into
a bath of cold oil to cool rapidly, then bit by bit use it to nibble
down the thread with cutting fluid, carefully checking every ~1/4 ofa
turn that you arent damaging the thread further. Personally I'd go with
the second option, but only because I like a challenge!

From previous threads, consider filing a few grooves across the threads
of the spare nut before hardening it, so it looks more like a typical die.
(Well, so it _works_ more like a typical die, but looking at one will tell
you what I'm talking about.)

Alan Braggins said:

From previous threads, consider filing a few grooves across the threads
of the spare nut before hardening it, so it looks more like a typical die.
(Well, so it _works_ more like a typical die, but looking at one will tell
you what I'm talking about.)

Very good point, this will improve the cutting and clearing action.
Although I don't suspect anyone asking the original question would
actually try this method :-).

Coyoteboy said:

Alan Braggins said:

From previous threads, consider filing a few grooves across the
threads of the spare nut before hardening it, so it looks more like a
typical die. (Well, so it _works_ more like a typical die, but looking
at one will tell you what I'm talking about.)

Very good point, this will improve the cutting and clearing action.
Although I don't suspect anyone asking the original question would
actually try this method :-).

I bought a new bike when this happened.

Worked for me ;o)

Nick said:

Coyoteboy said:

Alan Braggins said:

From previous threads, consider filing a few grooves across the
threads of the spare nut before hardening it, so it looks more like a
typical die. (Well, so it _works_ more like a typical die, but looking
at one will tell you what I'm talking about.)

Quoted message said:

Very good point, this will improve the cutting and clearing action.
Although I don't suspect anyone asking the original question would
actually try this method :-).

I bought a new bike when this happened.

Worked for me ;o)

http://concepttools.co.uk/p/AE-IMPERIAL-THREAD-FILE-1549.aspx

Pretty good if the thread structure is largely intact
and just needs a clean up.
Each file has 8 pitches on it.

Link for the picture only. No idea about the supplier.

Handy thing for the toolbox.