bottom Bracket installation question...

[Me]

Hi I have a three year old Shimano UN91 BB and it doesn't seem to be screwing into my frame
very easily.

I've tried 2 other Shimano BBs and they both go in by hand.

But neither side of this one is easy to put more than a thread or two in by any means.

I'm afraid to put a wrench on it and give it some torque for fear of damaging my frame.

I was wondering if perhaps this could be an Italian thread pitch instead of a standard English.

Does anyone know if Shimano makes Italian threaded stuff?

Also, how do I tell from looking at it if I have an italian or english bottom bracket?

Look forward to your answers...

-cheers

 

[Mike S.]

"Me" <[email protected]> wrote in message news:[email protected]...
> Hi I have a three year old Shimano UN91 BB and it doesn't seem to be screwing into my frame
> very easily.
>
> I've tried 2 other Shimano BBs and they both go in by hand.
>
> But neither side of this one is easy to put more than a thread or two in
by
> any means.
>
> I'm afraid to put a wrench on it and give it some torque for fear of damaging my frame.
>
> I was wondering if perhaps this could be an Italian thread pitch instead
of
> a standard English.
>
> Does anyone know if Shimano makes Italian threaded stuff?
>
> Also, how do I tell from looking at it if I have an italian or english bottom bracket?
>
> Look forward to your answers...
>
>
> -cheers
>
>

Italian BBs should say something like 70x1.xx, and English BBs say 68x1.xx. Since I don't remember
the exact thread counts, I'm not going to guess.

Sometimes I've had BBs that had more crud in them than others. You may want to have your LBS chase
out the threads before installing the new BB.

Don't force things! That's the quickest way to really screw things up. I've had good luck with
finicky BBs by threading in the non-drive side first to act as a guide for the drive side. If that
don't work, off to the LBS. Hopefully, they'll teach you what you were doing wrong (if anything),
rather than just doing it for you.

Mike

 

[Paul Southworth]

In article <[email protected]>, Mike S. <mikeshaw2@coxDOTnet> wrote:
>
>"Me" <[email protected]> wrote in message news:[email protected]...
>> Hi I have a three year old Shimano UN91 BB and it doesn't seem to be screwing into my frame very
>> easily.
>>
>> I've tried 2 other Shimano BBs and they both go in by hand.
>>
>> But neither side of this one is easy to put more than a thread or two in
>by
>> any means.
>>
>> I'm afraid to put a wrench on it and give it some torque for fear of damaging my frame.
>>
>> I was wondering if perhaps this could be an Italian thread pitch instead
>of
>> a standard English.
>>
>> Does anyone know if Shimano makes Italian threaded stuff?
>>
>> Also, how do I tell from looking at it if I have an italian or english bottom bracket?
>>
>> Look forward to your answers...
>>
>>
>> -cheers
>>
>>
>
>Italian BBs should say something like 70x1.xx, and English BBs say 68x1.xx. Since I don't remember
>the exact thread counts, I'm not going to guess.

68 and 70 are the respective shell widths, not the threading.

English/ISO is 68mm wide, 1.37" x 24tpi with left hand thread on the drive side.

Ital is 70mm wide, 36mm x 24tpi with right hand thread on both sides.

Yes Shimano definitely makes Italian thread BBs.

--Paul

 

[Me]

Thanks Paul and Mike,

Just checkd the BB and it has BC 1.37 stamped on the side so at least I know its an ISO English
thread. Yea!

So that means I'm working with the right stuff and only need to get it in.

Mike when you wrote that a LBS should be able to cleanup the thread for me did you mean on the BB
shell or the BB itself?

Its a Ti frame and I have 2 other BBs that slide in by hand and no visible sign of gunk in the BB
shell. But I've been trying my best to clean up the threads on the BB itself. Any suggestions on how
to really get down in the threads and get out 3 years worth of locktight/grease/and clay?

Is there a tool for such things?

-cheers

"Paul Southworth" <[email protected]> wrote in message
news:yZJda.33632$A%[email protected]...
> In article <[email protected]>, Mike S. <mikeshaw2@coxDOTnet> wrote:
> >
> >"Me" <[email protected]> wrote in message
news:[email protected]...
> >> Hi I have a three year old Shimano UN91 BB and it doesn't seem to be screwing into my frame
> >> very easily.
> >>
> >> I've tried 2 other Shimano BBs and they both go in by hand.
> >>
> >> But neither side of this one is easy to put more than a thread or two
in
> >by
> >> any means.
> >>
> >> I'm afraid to put a wrench on it and give it some torque for fear of damaging my frame.
> >>
> >> I was wondering if perhaps this could be an Italian thread pitch
instead
> >of
> >> a standard English.
> >>
> >> Does anyone know if Shimano makes Italian threaded stuff?
> >>
> >> Also, how do I tell from looking at it if I have an italian or english bottom bracket?
> >>
> >> Look forward to your answers...
> >>
> >>
> >> -cheers
> >>
> >>
> >
> >Italian BBs should say something like 70x1.xx, and English BBs say
68x1.xx.
> >Since I don't remember the exact thread counts, I'm not going to guess.
>
> 68 and 70 are the respective shell widths, not the threading.
>
> English/ISO is 68mm wide, 1.37" x 24tpi with left hand thread on the drive side.
>
> Ital is 70mm wide, 36mm x 24tpi with right hand thread on both sides.
>
> Yes Shimano definitely makes Italian thread BBs.
>
> --Paul

 

[Per ElmsäTer]

Me wrote:
> Its a Ti frame and I have 2 other BBs that slide in by hand and no visible sign of gunk in the BB
> shell. But I've been trying my best to clean up the threads on the BB itself. Any suggestions on
> how to really get down in the threads and get out 3 years worth of locktight/grease/and clay?
>
> Is there a tool for such things?
>

Soak it in Coca Cola.

--
Perre

Remove the DOTs to reply

 

[Archer]

In article <[email protected]>, [email protected] says...
> Thanks Paul and Mike,
>
> Just checkd the BB and it has BC 1.37 stamped on the side so at least I know its an ISO English
> thread. Yea!
>
> So that means I'm working with the right stuff and only need to get it in.
>
> Mike when you wrote that a LBS should be able to cleanup the thread for me did you mean on the BB
> shell or the BB itself?
>
> Its a Ti frame and I have 2 other BBs that slide in by hand and no visible sign of gunk in the BB
> shell. But I've been trying my best to clean up the threads on the BB itself. Any suggestions on
> how to really get down in the threads and get out 3 years worth of locktight/grease/and clay?
>
> Is there a tool for such things?

Have you tried a wire brush? It should work well unless the threads are very fine.

--
David Kerber An optimist says "Good morning, Lord." While a pessimist says "Good Lord,
it's morning".

Remove the ns_ from the address before e-mailing.

 

[Mike S.]

The shell.

Mike

"Me" <[email protected]> wrote in message news:[email protected]...
> Thanks Paul and Mike,
>
> Just checkd the BB and it has BC 1.37 stamped on the side so at least I
know
> its an ISO English thread. Yea!
>
> So that means I'm working with the right stuff and only need to get it in.
>
> Mike when you wrote that a LBS should be able to cleanup the thread for me did you mean on the BB
> shell or the BB itself?
>
> Its a Ti frame and I have 2 other BBs that slide in by hand and no visible sign of gunk in the BB
> shell. But I've been trying my best to clean up the threads on the BB itself. Any suggestions on
> how to really get down in the threads and get out 3 years worth of locktight/grease/and clay?
>
> Is there a tool for such things?
>
> -cheers
>
>
> "Paul Southworth" <[email protected]> wrote in message
> news:yZJda.33632$A%[email protected]...
> > In article <[email protected]>, Mike S. <mikeshaw2@coxDOTnet> wrote:
> > >
> > >"Me" <[email protected]> wrote in message
> news:[email protected]...
> > >> Hi I have a three year old Shimano UN91 BB and it doesn't seem to be screwing into my frame
> > >> very easily.
> > >>
> > >> I've tried 2 other Shimano BBs and they both go in by hand.
> > >>
> > >> But neither side of this one is easy to put more than a thread or two
> in
> > >by
> > >> any means.
> > >>
> > >> I'm afraid to put a wrench on it and give it some torque for fear of damaging my frame.
> > >>
> > >> I was wondering if perhaps this could be an Italian thread pitch
> instead
> > >of
> > >> a standard English.
> > >>
> > >> Does anyone know if Shimano makes Italian threaded stuff?
> > >>
> > >> Also, how do I tell from looking at it if I have an italian or
english
> > >> bottom bracket?
> > >>
> > >> Look forward to your answers...
> > >>
> > >>
> > >> -cheers
> > >>
> > >>
> > >
> > >Italian BBs should say something like 70x1.xx, and English BBs say
> 68x1.xx.
> > >Since I don't remember the exact thread counts, I'm not going to guess.
> >
> > 68 and 70 are the respective shell widths, not the threading.
> >
> > English/ISO is 68mm wide, 1.37" x 24tpi with left hand thread on the drive side.
> >
> > Ital is 70mm wide, 36mm x 24tpi with right hand thread on both sides.
> >
> > Yes Shimano definitely makes Italian thread BBs.
> >
> > --Paul

 

[Paul Southworth]

In article <[email protected]>, Me <[email protected]> wrote:
>Thanks Paul and Mike,
>
>Just checkd the BB and it has BC 1.37 stamped on the side so at least I know its an ISO English
>thread. Yea!
>
>So that means I'm working with the right stuff and only need to get it in.
>
>Mike when you wrote that a LBS should be able to cleanup the thread for me did you mean on the BB
>shell or the BB itself?
>
>Its a Ti frame and I have 2 other BBs that slide in by hand and no visible sign of gunk in the BB
>shell. But I've been trying my best to clean up the threads on the BB itself. Any suggestions on
>how to really get down in the threads and get out 3 years worth of locktight/grease/and clay?
>
>Is there a tool for such things?

Solvent and a small wire brush, then blast with air compressor.

A bike shop could run a pair of piloted taps through it, but that may not be necessary if other BBs
seem to fit OK.

I would also look for damaged threads on the ill-fitting BB cups. Boogered threads can sometimes be
fixed up with a little file or pick.

--Paul

 

[Me]

Well, I's ME the origional poster.

From you advice thsi is what I did...

Bought a wire brush, scrubbed out the threads...

after that fixed cup side slid in without the need for a big wrench attached. coool!

the adjustable was very stiff so soaked it in coca-cola for two days and the wire brushed it and it
too slid in by hand.

Thanks for all your advice...

-jason

"Paul Southworth" <[email protected]> wrote in message
news:5xNda.33639$A%[email protected]...
> In article <[email protected]>, Me <[email protected]> wrote:
> >Thanks Paul and Mike,
> >
> >Just checkd the BB and it has BC 1.37 stamped on the side so at least I
know
> >its an ISO English thread. Yea!
> >
> >So that means I'm working with the right stuff and only need to get it
in.
> >
> >Mike when you wrote that a LBS should be able to cleanup the thread for
me
> >did you mean on the BB shell or the BB itself?
> >
> >Its a Ti frame and I have 2 other BBs that slide in by hand and no
visible
> >sign of gunk in the BB shell. But I've been trying my best to clean up
the
> >threads on the BB itself. Any suggestions on how to really get down in
the
> >threads and get out 3 years worth of locktight/grease/and clay?
> >
> >Is there a tool for such things?
>
> Solvent and a small wire brush, then blast with air compressor.
>
> A bike shop could run a pair of piloted taps through it, but that may not be necessary if other
> BBs seem to fit OK.
>
> I would also look for damaged threads on the ill-fitting BB cups. Boogered threads can sometimes
> be fixed up with a little file or pick.
>
> --Paul

 

[Archer]

In article <[email protected]>, [email protected] says...
> Well, I's ME the origional poster.
>
> From you advice thsi is what I did...
>
> Bought a wire brush, scrubbed out the threads...
>
> after that fixed cup side slid in without the need for a big wrench attached. coool!
>
> the adjustable was very stiff so soaked it in coca-cola for two days and the wire brushed it and
> it too slid in by hand.

Glad you got it going!

....

--
David Kerber An optimist says "Good morning, Lord." While a pessimist says "Good Lord,
it's morning".

Remove the ns_ from the address before e-mailing.

 

[Per ElmsäTer]

Me wrote:
> Well, I's ME the origional poster.
>
> From you advice thsi is what I did...
>
> Bought a wire brush, scrubbed out the threads...
>
> after that fixed cup side slid in without the need for a big wrench attached. coool!
>
> the adjustable was very stiff so soaked it in coca-cola for two days and the wire brushed it and
> it too slid in by hand.
>
> Thanks for all your advice...
>

Just love that ol' Coca Cola trick

--
Perre

Remove the DOTs to reply

 

[Mike S.]

"Per Elmsäter" <[email protected]> wrote in message
news[email protected]...
> Me wrote:
> > Well, I's ME the origional poster.
> >
> > From you advice thsi is what I did...
> >
> > Bought a wire brush, scrubbed out the threads...
> >
> > after that fixed cup side slid in without the need for a big wrench attached. coool!
> >
> > the adjustable was very stiff so soaked it in coca-cola for two days and the wire brushed it and
> > it too slid in by hand.
> >
> > Thanks for all your advice...
> >
>
> Just love that ol' Coca Cola trick
>

Works on toilet bowls too!

Mike
> --
> Perre
>
> Remove the DOTs to reply

 

[Leonard Miglior]

In article <[email protected]>, Mike S. <mikeshaw2@coxDOTnet> wrote:

> "Per Elmsäter" <[email protected]> wrote in message
> news[email protected]...
> > Me wrote:
> > > Well, I's ME the origional poster.
> > >
> > > From you advice thsi is what I did...
> > >
> > > Bought a wire brush, scrubbed out the threads...
> > >
> > > after that fixed cup side slid in without the need for a big wrench attached. coool!
> > >
> > > the adjustable was very stiff so soaked it in coca-cola for two days and the wire brushed it
> > > and it too slid in by hand.
> > >
> > > Thanks for all your advice...
> > >
> >
> > Just love that ol' Coca Cola trick
> >
>
> Works on toilet bowls too!
>
> Mike

Which reminds me of an off-topic event that occurred around 1964. I was working in a research lab
and the chemist, who claimed to have been Fidel Castro's Minister of Propaganda until a falling-out,
held up a can of Coca-Cola and said, "this is very powerful and terribly corrosive".

Maybe you had to have been there.