Broken Shimano XT Bottom Bracket Cup...

"Wes Crout" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

I have just recently purchased some '02 XTR equipment (BB, Crankset & Shifter/Lever Combos) that I
am wanting to install onto my bike (obviously). My old bottom bracket, a non-splined Shimano XT
(BB-UN72) seems to want to get in my way of doing so. I removed the non-fixed BB cup from the left
side, then the rest of the bottom bracket. The problem enters here. The movable BB cup from the
left side (cheaper plastic) broke in half somehow while still in the frame. I therefore have half
of the cup remaining. I am unsure how to safely remove this without damaging the threads on the
frame. On the portion of the cup that removed, there are only about 4 or 5 of the threads, leaving
a good portion of cup in the frame to work with. I cannot grip it with anything that I know of, so
any suggestions would be greatly appreciated. I will obviously take it the the LBS sooner or later
if I am unable to remedy this myself. I would call them right now, but they are closed until the
morning. I was in a rhythm, and would like to continue this project tonight. Thanx in advance...

Since the lip is off the cup, did you try just unscrewing it? There's nothing preventing it from
turning now. Press outward with both thumbs while turning.

If you tap under the edge of it with a pick or a small chisel ( or someone else's screwdriver!) they
are easy to shatter. No risk of damaging the frame's threads to any meaningful extent although there
may be a small ding where the tool hit.

--
Andrew Muzi yellowjersey.orgyellowjersey.orgOpen ↗ Open every day since 1 April 1971

"A Muzi" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

"Wes Crout" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I have just recently purchased some '02 XTR equipment (BB, Crankset & Shifter/Lever Combos) that
I am wanting to install onto my bike (obviously). My old bottom bracket, a non-splined Shimano
XT (BB-UN72) seems to want to get in my way of doing so. I removed the non-fixed BB cup from the
left side, then the rest of the bottom bracket. The problem enters here. The movable BB cup from
the left side (cheaper plastic) broke in half somehow while still in the frame. I therefore have
half of the cup remaining (snip)

Since the lip is off the cup, did you try just unscrewing it? There's nothing preventing it from
turning now. Press outward with both thumbs while turning.

Since the cup fell to pieces, I wonder if there's some corrosion holding the cup in place.

Quoted message said:

If you tap under the edge of it with a pick or a small chisel ( or someone else's screwdriver!)
they are easy to shatter. No risk of damaging the frame's threads to any meaningful extent
although there may be a small ding where the tool hit.

Carefully quartering the cup with a hacksaw blade first will probably make this easier, also. I'd
really clean out the threads and inspect them before inserting the new cup. No sense in getting it
jammed or cross-threaded in a buggered BB shell.

Jeff

"Jeff Wills" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

....I'd really clean out the threads and inspect them before inserting the new cup. No sense in
getting it jammed or cross-threaded in a buggered BB shell.

That is important advice for anyone installing a new BB even if the old one came out nice and easy.
Make sure those shell threads are clean, "like it's your job!". I learned my lesson the hard way.
One piece of grit is all it takes to bugger up those soft plastic/aluminium threads.

Mike

Michael Dart said:

"Jeff Wills" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

....I'd really clean out the threads and inspect them before inserting the new cup. No sense in
getting it jammed or cross-threaded in a buggered BB shell.

That is important advice for anyone installing a new BB even if the old one came out nice and easy.
Make sure those shell threads are clean, "like it's your job!". I learned my lesson the hard way.
One piece of grit is all it takes to bugger up those soft plastic/aluminium threads.

Mike

to remove the remains - get a big file, just a bit smaller than the bb... they are generally
tapered. Feed the file in till it snugs up against the plastic. The file's sharp edges will grip
well enuff to thread it out. You want a file with a taper h that will touch the plastic without
touching the threads - Ъ×

I would like to thank you all for your advice. The old cup remains have successfully been removed,
and I will be installing the new BB and crank tonight. I will clean all threads immensely, like it
is "my job." Thanx again.

Wes