Integrated BB/Crankset question

Quoted message said:

While installing my 111/68 English thread AC-H bottom bracket two
years ago, I mucked up the bottom bracket shell threads in my Nashbar
frame. And the threads on the BB fixed cup also. A local shop was
able to run a tap through the shell and clean up the threads in the
shell and took a wire bruch to the fixed cup threads and clean them
up too. Put it all together and it lasted well enough for 1.5 years
and several thousand miles. Then it came loose and I tightened the
BB cups up. Lasted another 6 months just fine. Now it has come loose
again and tightening the fixed cup has not kept it tight for even a
day of riding.

Options:
1. New Nashbar frame for about $120 and put in a new AC-H 111/68 BB I
have already. And transfer all of the parts to the new frame.

Sounds the best here... it allows flexible BB options in the future.

Quoted message said:

2. Have the current mucked up shell rethreaded for Italian threading
and buy a new AC-H in Italian. $50 for rethreading(?) and $25 for new
Italian threaded BB.

Locks yourself into Italian for years to come... that's a mighty cheap IT BB
you have specced there... what is it?

Quoted message said:

3. And the question about integrated BB/Cranksets as the thread title
suggests. Would an integrated BB/crankset such as the new 10 speed
Shimano Ultegra 6603 triple fix my loosening fix cup problem.

Nope. The crankset and bottom bracket will rotate and get loose together in
the frame until enough play develops that the shell no longer holds the cups
tight. Lots of aluminum/aluminum contact and lots of stripping. It also
puts a lot of stress on the BB cups since the cups are generally unsupported
from torque (bearings are far away from threads).

Quoted message said:

Does
the pinch bolt and pre-load method of installing the integrated
BB/crankset keep the BB cups from loosening. Would the separate
bottom bracket cups on the integrated BB/crankset stay in place on
mucked up bottom bracket shell threads due to the BB/crankset arms
locking the cups in place and preventing them from coming loose.
This option, if it would work as I am asking, would be about $250+
for BB/crank and the separate BB cups. Most expensive but a new and
different piece of equipment is acquired. Although it is Shimano.

--
Phil, Squid-in-Training

Phil said:

Quoted message said:

While installing my 111/68 English thread AC-H bottom bracket two
years ago, I mucked up the bottom bracket shell threads in my Nashbar
frame. And the threads on the BB fixed cup also. A local shop was
able to run a tap through the shell and clean up the threads in the
shell and took a wire bruch to the fixed cup threads and clean them
up too. Put it all together and it lasted well enough for 1.5 years
and several thousand miles. Then it came loose and I tightened the
BB cups up. Lasted another 6 months just fine. Now it has come loose
again and tightening the fixed cup has not kept it tight for even a
day of riding.

Options:
1. New Nashbar frame for about $120 and put in a new AC-H 111/68 BB I
have already. And transfer all of the parts to the new frame.

Sounds the best here... it allows flexible BB options in the future.

Not too worried about changing bottom brackets since the 111 mm
Campagnolo AC-H or Centaur 111 mm bottom bracket are about the only two
decent bottom brackets that fit Centaur cranks. Don't think I'll be
changing the cranks unless they break.

Quoted message said:

Quoted message said:

2. Have the current mucked up shell rethreaded for Italian threading
and buy a new AC-H in Italian. $50 for rethreading(?) and $25 for new
Italian threaded BB.

Locks yourself into Italian for years to come... that's a mighty cheap IT BB
you have specced there... what is it?

http://www.cambriabike.com/shopexd.asp?id=24973

Campagnolo AC-H bottom bracket. Italian threading. 111 mm length.

Quoted message said:

Quoted message said:

3. And the question about integrated BB/Cranksets as the thread title
suggests. Would an integrated BB/crankset such as the new 10 speed
Shimano Ultegra 6603 triple fix my loosening fix cup problem.

Nope. The crankset and bottom bracket will rotate and get loose together in
the frame until enough play develops that the shell no longer holds the cups
tight. Lots of aluminum/aluminum contact and lots of stripping. It also
puts a lot of stress on the BB cups since the cups are generally unsupported
from torque (bearings are far away from threads).

So this isn't really an option since the crank arms don't lock the
bottom bracket together and keep the external bearing cups from
loosening.

Quoted message said:

Quoted message said:

Does
the pinch bolt and pre-load method of installing the integrated
BB/crankset keep the BB cups from loosening. Would the separate
bottom bracket cups on the integrated BB/crankset stay in place on
mucked up bottom bracket shell threads due to the BB/crankset arms
locking the cups in place and preventing them from coming loose.
This option, if it would work as I am asking, would be about $250+
for BB/crank and the separate BB cups. Most expensive but a new and
different piece of equipment is acquired. Although it is Shimano.

--
Phil, Squid-in-Training

Quoted message said:

Phil said:

Quoted message said:

While installing my 111/68 English thread AC-H bottom bracket two
years ago, I mucked up the bottom bracket shell threads in my
Nashbar frame. And the threads on the BB fixed cup also. A local
shop was able to run a tap through the shell and clean up the
threads in the shell and took a wire bruch to the fixed cup threads
and clean them up too. Put it all together and it lasted well
enough for 1.5 years and several thousand miles. Then it came
loose and I tightened the BB cups up. Lasted another 6 months just
fine. Now it has come loose again and tightening the fixed cup has
not kept it tight for even a day of riding.

Options:
1. New Nashbar frame for about $120 and put in a new AC-H 111/68
BB I have already. And transfer all of the parts to the new frame.

Sounds the best here... it allows flexible BB options in the future.

Not too worried about changing bottom brackets since the 111 mm
Campagnolo AC-H or Centaur 111 mm bottom bracket are about the only
two decent bottom brackets that fit Centaur cranks. Don't think I'll
be changing the cranks unless they break.

Quoted message said:

Quoted message said:

2. Have the current mucked up shell rethreaded for Italian
threading and buy a new AC-H in Italian. $50 for rethreading(?)
and $25 for new Italian threaded BB.

Locks yourself into Italian for years to come... that's a mighty
cheap IT BB you have specced there... what is it?

http://www.cambriabike.com/shopexd.asp?id=24973

Campagnolo AC-H bottom bracket. Italian threading. 111 mm length.

Quoted message said:

Quoted message said:

3. And the question about integrated BB/Cranksets as the thread
title suggests. Would an integrated BB/crankset such as the new 10
speed Shimano Ultegra 6603 triple fix my loosening fix cup problem.

Nope. The crankset and bottom bracket will rotate and get loose
together in the frame until enough play develops that the shell no
longer holds the cups tight. Lots of aluminum/aluminum contact and
lots of stripping. It also puts a lot of stress on the BB cups
since the cups are generally unsupported from torque (bearings are
far away from threads).

So this isn't really an option since the crank arms don't lock the
bottom bracket together and keep the external bearing cups from
loosening.

You keep mentioning loosening when in fact there is plastic
deformation/fatigue of the metal. The threads of the shell are moving every
time you tighten down the BB. Eventually, these threads will shear off,
leaving nothing to hold the bottom bracket cups from (microscopically)
moving and wearing away at the shell itself. Sure, the cranks may hold the
BB in place, but do you want all that moving around?

Imagine taking an old bottom bracket spindle and putting it through the
shell with no bearings in it. Then attach the cranks and begin pedaling.
This is an extreme example of what would be happening. *cue someone
correcting me*

--
Phil, Squid-in-Training

Option 4.

Loctite Form-a-Thread
I tried three years ago on a utility bike, it worked once, and continues
to work.
I have never had to disassemble it though and honestly dread the thought
It might be a cheap solution to buy time for a cheap frame as it has
been for me.

Marcus

Quoted message said:

Option 4.

Loctite Form-a-Thread
I tried three years ago on a utility bike, it worked once, and continues
to work.
I have never had to disassemble it though and honestly dread the thought
It might be a cheap solution to buy time for a cheap frame as it has
been for me.

Marcus

On last night's ride a friend suggested something similar. JB Weld to
glue/weld the fixed cup threads to the bottom bracket shell. For the
cost of a $20 Campagnolo AC-H bottom bracket, which I already own, this
sounds like the best option. When the bottom bracket gives out, I
doubt I would be able to get the bottom bracket out to change it, the
frame can be replaced for $100. I'll go to the auto parts store and
look for the Loctite stuff and JB Weld.

I also thought of doing the JB Weld epoxy AND having my brother weld,
real aluminum TIG weld, the aluminum fixed cup to the aluminum frame's
bottom bracket shell. Permanent. If the JB Weld epoxy does not work,
I will try the real welding route.

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

Quoted message said:

Quoted message said:

Option 4.

Loctite Form-a-Thread
I tried three years ago on a utility bike, it worked once, and continues
to work.
I have never had to disassemble it though and honestly dread the thought
It might be a cheap solution to buy time for a cheap frame as it has
been for me.

Marcus

On last night's ride a friend suggested something similar. JB Weld to
glue/weld the fixed cup threads to the bottom bracket shell. For the
cost of a $20 Campagnolo AC-H bottom bracket, which I already own, this
sounds like the best option. When the bottom bracket gives out, I
doubt I would be able to get the bottom bracket out to change it, the
frame can be replaced for $100. I'll go to the auto parts store and
look for the Loctite stuff and JB Weld.

I also thought of doing the JB Weld epoxy AND having my brother weld,
real aluminum TIG weld, the aluminum fixed cup to the aluminum frame's
bottom bracket shell. Permanent. If the JB Weld epoxy does not work,
I will try the real welding route.

Make sure you get the glue all up in there. Otherwise, you may very well
end up with a permanently creaking frame.

--
Phil, Squid-in-Training