Bottom bracket servicing

Old style BB with separate cups (and square taper, not _really_
old with cotter pins). The bike (and bottom bracket) is about 15
years old, but there have been times it hasn't been used much.
The bracket is running smoothly enough at the moment, but it's
been a few years since it was last greased.

The threads for a crank remover on the left hand crank have stripped.

Should I
[ ] undo the non-adjustable cup (assuming I can [1])
[ ] not bother trying to service it until it actually gives problems and
replace the whole thing (probably with a sealed bearing BB).
[ ] take the left crank off with a ball joint splitter, being prepared
to replace it.

[1] http://www.sheldonbrown.com/tooltips/bbcups.html says
"For normal servicing, only the adjustable (left) cup need be removed. It is
a bad idea to remove the fixed (right) cup for a routine cleaning and
repacking. The fixed cup should only be removed when it is going to be
replaced with another one, as when replacing an entire crankset."
In spite of that I did remove the fixed cup last time I greased it
(probably because I hadn't read Sheldon at the time), but it seems
to be rather more stuck now.

On Sun, 11 Jan 2009, Alan Braggins wrote:

Old style BB with separate cups (and square taper, not _really_
old with cotter pins). The bike (and bottom bracket) is about 15
years old, but there have been times it hasn't been used much.
The bracket is running smoothly enough at the moment, but it's
been a few years since it was last greased.

The threads for a crank remover on the left hand crank have stripped.

Should I
[ ] undo the non-adjustable cup (assuming I can [1])
[oh hell yes] not bother trying to service it until it actually gives problems and
replace the whole thing (probably with a sealed bearing BB).
[ ] take the left crank off with a ball joint splitter, being prepared
to replace it.

This is assuming you don't get kinky thrills out of painstakingly
servicing obsolete machinery. A new BB costs all of ten quid.

But if the extractor thread is gone, can you get it out at all? Or rather,
will you be able to get the crank off in order to change it? I guess you
fall back to less subtle means, viz lump hammer.

tom

--
We must perform a quirkafleeg

On Sun, 11 Jan 2009 19:01:54 +0000, Tom Anderson
said in
:

But if the extractor thread is gone, can you get it out at all? Or rather,
will you be able to get the crank off in order to change it? I guess you
fall back to less subtle means, viz lump hammer.

A bearing puller or balljoint separator can do the job in extremis.
And of course we all have those, don't we? Next tot he brake pipe
tool and the trolley jack on the Dexion shelving?

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk
85% of helmet statistics are made up, 69% of them at CHS, Puget Sound
GPG sig #3FA3BCDE http://www.chapmancentral.co.uk/pgp-public-key.txt

In article , Tom Anderson wrote:
On Sun, 11 Jan 2009, Alan Braggins wrote:

Old style BB with separate cups (and square taper, not _really_
old with cotter pins). The bike (and bottom bracket) is about 15
years old, but there have been times it hasn't been used much.
[...]
[oh hell yes] not bother trying to service it until it actually gives problems and
[...]
This is assuming you don't get kinky thrills out of painstakingly
servicing obsolete machinery.

No comment.

A new BB costs all of ten quid.

Only if I resist the temptation to upgrade the crankset to Hollowtech
while I'm about it....

In article , Just zis Guy, you know? wrote:
On Sun, 11 Jan 2009 19:01:54 +0000, Tom Anderson
said in
:

But if the extractor thread is gone, can you get it out at all? Or rather,
will you be able to get the crank off in order to change it? I guess you
fall back to less subtle means, viz lump hammer.

A bearing puller or balljoint separator can do the job in extremis.
And of course we all have those, don't we? Next tot he brake pipe
tool and the trolley jack on the Dexion shelving?

I don't actually have a brake pipe flaring kit. I do have the balljoint
separator mentioned in the original post. Last time I had to resort to
it, the crank involved was unusable afterwards, but that was a right hand
one (on a different bike). In the worst case, I also have an angle grinder.
(Or did you just mean a brake pipe spanner? I do have one of those.)

In article , Alan Braggins wrote:
In article , Tom Anderson wrote:

A new BB costs all of ten quid.

Only if I resist the temptation to upgrade the crankset to Hollowtech
while I'm about it....

Actually I might have misspelt "Campagnolo groupset" there, since it's using
Ergo levers and Hubbub modification at the moment.

Alan Braggins wrote:
Old style BB with separate cups (and square taper, not _really_
old with cotter pins).

I do have a BB with cotter pins, and reading Sheldon on the
subject has left me hoping it never needs servicing :-)

-- PMM

Alan Braggins wrote:
Old style BB with separate cups (and square taper, not _really_
old with cotter pins). The bike (and bottom bracket) is about 15
years old, but there have been times it hasn't been used much.
The bracket is running smoothly enough at the moment, but it's
been a few years since it was last greased.

The threads for a crank remover on the left hand crank have stripped.

Should I
[ ] undo the non-adjustable cup (assuming I can [1])
[ ] not bother trying to service it until it actually gives problems
and replace the whole thing (probably with a sealed bearing BB).
[ ] take the left crank off with a ball joint splitter, being prepared
to replace it.

I'd probably leave alone unless its giving trouble.

However, if wanting to remove it, a crankpulling tool is less brutal than
most ball-joint splitters. (Crank-puller being three-arms which clip behind
the crank arm, and a central screw pin which can be wound into the crank
axle).

The well equiped home bodger would weld-up their own custom crank puller -
bottom plate being steel with slot in it which will slide between bike crank
and LH cup, three or four bolts hold this to top plate, which has central
screw thread to wind in against axle. (No I've not made one, but have done
something similar for removing the rear bearings from the back of an ancient
car. Whilst the car went to the scrappy around 20 years ago, the puller
still lurks in the depths of the garage just incase I have buy another
ancient car :-) ).


- Nigel


--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/

On 11 Jan 2009 19:38:46 +0000 (GMT),
(Alan Braggins) said in
:

(Or did you just mean a brake pipe spanner? I do have one of those.)

No, a flaring tool:
http://www.chapmancentral.co.uk/wiki/Image:Brake-tool-2.jpg

A hangover from past times, of course :-)

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk
85% of helmet statistics are made up, 69% of them at CHS, Puget Sound
GPG sig #3FA3BCDE http://www.chapmancentral.co.uk/pgp-public-key.txt

Alan Braggins formulated the question :


The threads for a crank remover on the left hand crank have stripped.


Have they really, really stripped? Some of the crappier removers will
happily damage threads, but being so badly made leave enough thread for
a decent extractor (Campag used to make a great one) to just about do
the job.

Someone also used to make a tap for cranks, with a guide that screwed
into the axle, but I can't remember who now - sorry. However, you still
need enough metal left to be able to do this, obviously.

--
Simon