Can't remove B.bracket - help, pls!

BigBenBiker said:

Hi All,

I'm trying to change my bb. This is the first time I'm trying such
thing, and I'm surprised that after getting what seems the right tool,
that engages in the notches around the bb, although not as deeply as
though it would, despite pulling hard on the wrench (in the direction
opposite to pedaling motion) it doesn't move :-O

It's possible you have an Italian-threaded BB on which both sides
unscrew in the normal sense, i.e. LHS in direction of pedalling motion,
but RHS the other way.

Some of them have arrows engraved on them indicating which way they
tighten up.

Quoted message said:

Is there such a thing as BBs stuck to frames, like some stems after a
long time without being removed??

I've known them to be very difficult to get out.

Quoted message said:

Sugestions, please?

Penetrating oil I suppose. I've not tried this but my plan for next time
is to see if I can find some drain holes on the bottom of the BB shell
and squirt some penetrating oil in there to try to get it to the
threads.

Let us know how you do get it out in the end.

clean the groove between BB and frame with brush/razor blade
then apply PC Blaster for 1-2 weeks. Wrap a PC soaked cloth arond the
groove after dripping a fresh batch in every 5- hours
run over to Home Depot. Buy the largest vice grip. measure the Nut.
measure or read the vice grip info so you know the grip will fit
before running back.
while there, get a turbo torh and a can of Mapp gas
wrap AL foil around delicate parts that could be hit with flame or
heat up and disinteragate.
adjust grips to fit. choose the position.
heat frame till the sucker smokes. then vice grip.
clean all threads with BB brush from bikepartsect.
or a small brass brush from NAPA using PC blaster as solvent on
threads/brush.
when vice gripping move right/left right/left loosen-tighten to move
the debris in there on the threads to one side rather than loosen
loosen causing the debris to dam up and jam the operation.

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

Quoted message said:

Hi All,

I'm trying to change my bb. This is the first time I'm trying such
thing, and I'm surprised that after getting what seems the right tool,
that engages in the notches around the bb, although not as deeply as
though it would, despite pulling hard on the wrench (in the direction
opposite to pedaling motion) it doesn't move :-O

Is there such a thing as BBs stuck to frames, like some stems after a
long time without being removed??

Sugestions, please?

TIA,
jbr

Ride your 2 wheels, but in order to ride them yet another day!
bbb

Hi bbb,

I removed my BB recently, for the 1st time on this bike. (And this was my
1st experience removing any BB at all.)

Make ABSOLUTELY sure you are turning in the correct direction. On my bike,
the left side of the BB is removed by turning the conventional way,
counter-clockwise. The right side of my BB is removed by turning CLOCKWISE.
I had no trouble removing the left side, but since I tend to only read
instructions AFTER I get in trouble, the right side was really 'good and
tight' before I read the Park website instructions
http://www.parktool.com/repair/readhowto.asp?id=94 . At that point, I had to
buy a length of pipe for additional leverage to extend my socket drive
wrench. I was then able to remove the BB, and I feel foolish for not doing
my homework before attempting my BB project - J.

(BigBenBiker) said:

Hi All,

I'm trying to change my bb. This is the first time I'm trying such
thing, and I'm surprised that after getting what seems the right tool,
that engages in the notches around the bb, although not as deeply as
though it would, despite pulling hard on the wrench (in the direction
opposite to pedaling motion) it doesn't move :-O

Is there such a thing as BBs stuck to frames, like some stems after a
long time without being removed??

Sugestions, please?

TIA,
jbr

Ride your 2 wheels, but in order to ride them yet another day!
bbb

Hi there.

Is this a cartridge bottom bracket?

Peter

Sir Ridesalot said:

Is this a cartridge bottom bracket?

Yes, it is. I've been working on the pedaling side only, so far,
trying to rotate it counter-clockwise.

Regards,
bbb

Ben C said:

It's possible you have an Italian-threaded BB on which both sides
unscrew in the normal sense, i.e. LHS in direction of pedalling motion,
but RHS the other way.

I don't think I have an Italian threaded BB. I can't recall the exact
measures right now, but I can tell you we're talking about a Trek MTB
frame.

Quoted message said:

Some of them have arrows engraved on them indicating which way they
tighten up.

I'll inspect closer searching for that.

Quoted message said:

Penetrating oil I suppose. I've not tried this but my plan for next time

OK, I'll give that a try.

Thanks!
bbb

On 26 Apr 2007 15:57:41 -0700, "[email hidden]"
<[email hidden]> wrote:

I'm sure I'd feel confident doing that kind of work myself...

I'll try the local equivalent of PC blaster, and see what gives.

Thanks!
bbb

Quoted message said:

clean the groove between BB and frame with brush/razor blade
then apply PC Blaster for 1-2 weeks. Wrap a PC soaked cloth arond the
groove after dripping a fresh batch in every 5- hours
run over to Home Depot. Buy the largest vice grip. measure the Nut.
measure or read the vice grip info so you know the grip will fit
before running back.
while there, get a turbo torh and a can of Mapp gas
wrap AL foil around delicate parts that could be hit with flame or
heat up and disinteragate.
adjust grips to fit. choose the position.
heat frame till the sucker smokes. then vice grip.
clean all threads with BB brush from bikepartsect.
or a small brass brush from NAPA using PC blaster as solvent on
threads/brush.
when vice gripping move right/left right/left loosen-tighten to move
the debris in there on the threads to one side rather than loosen
loosen causing the debris to dam up and jam the operation.

(BigBenBiker) said:

On 26 Apr 2007 17:22:47 -0700, Sir Ridesalot

Quoted message said:

Is this a cartridge bottom bracket?

Yes, it is. I've been working on the pedaling side only, so far,
trying to rotate it counter-clockwise.

Regards,
bbb

Sometimes you can secure the BB tool with a quick release lever from a
wheel. If there's no hole through the center of your BB spindle, you
can get a tool designed for this from a bike shop. Now that you don't
have to worry about the tool slipping out of the splines, you can get
vicious with it. Either twist it out of there with a long wrench, or
else take the wheels off, stick the BB tool into a vise, and turn the
frame. The latter approach always works (although if it's horribly
corroded in there, you'll destroy your frame's BB threads - rare, but
it happens.)

-Vee

yeah. there's a shimano cartridge BB here in the dining room. looks
like you can file two flats on the cup for the vise grips.
afetr you heat it till it smokes once. allow to cool then add the PC
blaster again. Blaster is at WalMart: conatins magnetic particles
carrying the fluid onward, also corrosive which you may need.
Sometimes after heating when the original, if you lucked out here,
loctite disintegrates powdering to a thread lube form, additional
corrosion best though of as sandy dirt then jams the operation. Adding
a very LIGHT lube fluid like Blaster may help more than more heat. BUT
in any case, once you get it moving evr so slightly probabbbbly by
rapping the vice grips 'once' with a hammer, lube it with PC.
USE HEAT

BigBenBiker said:

Yes, it is. I've been working on the pedaling side only, so far,
trying to rotate it counter-clockwise.
Regards,
bbb

Unless you have an Italian frame that's your problem. Odds are you
ahve an ISO bottom bracket and by trying to turn it counter clockwise
you are actually tightening it. The "pedalling" side-I assume you
nmean the side with the chainrings because you pedal from both sides-
is left hand threaded. Try it clockwise.
Phil Brown

(BigBenBiker) said:

Hi All,

I'm trying to change my bb. This is the first time I'm trying such
thing, and I'm surprised that after getting what seems the right tool,
that engages in the notches around the bb, although not as deeply as
though it would, despite pulling hard on the wrench (in the direction
opposite to pedaling motion) it doesn't move :-O

There's your problem right there - that's the tightening direction. To
unscrew you go the SAME direction as pedaling. Drive side has left-
hand threads, and non-drive side has right hand threads. It's the
other way around for pedals though.

The rotation of the bearings lightly pushes the cups opposite the
pedaling direction, so they won't come loose.

Hank Wirtz said:

The rotation of the bearings lightly pushes the cups opposite the
pedaling direction, so they won't come loose.

But the pedal shaft doesn't spin, it's fixed in the crank. The pedal
itself is held relatively fixed by your foot. If you follow the odd
orbit around, the bearings are pushed one way in the front of the
stroke, and then the other way in the rear.

Someone snipes:

Quoted message said:

Quoted message said:

The rotation of the bearings lightly pushes the cups opposite the
pedaling direction, so they won't come loose.

Quoted message said:

But the pedal shaft doesn't spin, it's fixed in the crank. The pedal
itself is held relatively fixed by your foot. If you follow the odd
orbit around, the bearings are pushed one way in the front of the
stroke, and then the other way in the rear.

I think you can visualize the direction of the load on the pedal shaft
that rotates in space and has primarily a downward force applied to
it... along with some upward strokes of lesser duration and magnitude
on occasion. Therefore, the pedal spindle is loaded as it rotates
while attached to the crank and supports a downward load. Whether the
spindle rotates under unidirectional load or the load rotates about
the spindle is irrelevant. From this the spindle threads move in the
crank, no matter how tight you make it. That is why it needs a left
hand thread on the left crank.

The right BB cup has a up an down force, depending on which pedal is
pushing down and with these motions, the chain pulls rearward.
Therefore, there is 3/4 of a circular load on the cup and because it
doesn't have a tapered face (like and automobile lug nut) to withstand
radial loads, it frets in its threads in a motion that wants to loosen
a right hand thread. Because, bicycles have survived with this crude
attachment for many years, no one is stepping up to change the BB
shell diameter (it is too small) or change the face of it (it should
be conical).

Most bicycles today, in contrast to 40 years ago, use left hand
threads on right BB cups to counter that effect. Just the same,
fretting continues even if the cup does not unscrew. Over the course
of approximately 40,000 miles my BB threads eroded to nothing so the
cup could be pried out with a screw driver... all that from
continuous fretting.

Rotation of these loaded joints is caused by precession, an effect
that can be demonstrated by making a ring of thumb and forefinger and
rolling the opposite index finger around in that ring. Rotation of
the index finger is opposite to the load path as it rolls around the
circle.

Jobst Brandt

Quoted message said:

Hank Wirtz said:

The rotation of the bearings lightly pushes the cups opposite the
pedaling direction, so they won't come loose.

still me said:

But the pedal shaft doesn't spin, it's fixed in the crank. The pedal
itself is held relatively fixed by your foot. If you follow the odd
orbit around, the bearings are pushed one way in the front of the
stroke, and then the other way in the rear.

Such an odd machine you ride! Got photos of that contraption?

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Because, bicycles have survived with this crude

Quoted message said:

attachment for many years, no one is stepping up to change the BB
shell diameter (it is too small) or change the face of it (it should
be conical).

a conically faced BB cup? and where would the conical face be formed?
as the threaded conical face or...?

if locktite is liberally used then no fretting occurs. or am I
repeating myself?

I haven't used vice grips on an aluminum shimano BB: does the BB
easily deform? I guess it doesn't matter as the unit was design as
disposable.

datakoll? said:

Quoted message said:

Because, bicycles have survived with this crude attachment for many
years, no one is stepping up to change the BB shell diameter (it is
too small) or change the face of it (it should be conical).

Quoted message said:

a conically faced BB cup? and where would the conical face be
formed? as the threaded conical face or...?

Quoted message said:

if Loctite is liberally used then no fretting occurs. or am I
repeating myself?

I suggest you put a tandem left crank (right hand thread) on your
bicycle and see if you can keep it from loosening. Th forces there
are great enough top make aluminum yield and fret. Loctite is not as
strong as aluminum and even if it were, the aluminum will yield.

Quoted message said:

I haven't used vice grips on an aluminum Shimano BB: does the BB
easily deform? I guess it doesn't matter as the unit was design as
disposable.

I guess you missed the crank modification I made to address this
problem after breaking at least one crank per year for more than two
dozen years.

http://www.chiark.greenend.org.uk/~damerell/bikes/brandt-cranks.jpg

I haven't even inspected a crank since I made this modification a few
years ago. It simulated a pedal spindle with a 90° conical taper.
The split allows it to be positioned in the thread relief and
tightening it closes it like a collet on the spindle. The crank in
the foreground shows the fretting erosion that occurs.

http://pardo.net/bike/pic/fail-001/FAIL-016.html

This picture shows my last crank failure with an arrow on the crack
that goes nearly through that side of the pedal eye.

Jobst Brandt

Quoted message said:

Because, bicycles have survived with this crude

Quoted message said:

attachment for many years, no one is stepping up to change the BB
shell diameter (it is too small) or change the face of it (it should
be conical).

a conically faced BB cup? and where would the conical face be formed?
as the threaded conical face or...?

well, we could have a nice thick bb shell, conical face and a nice big
conical land on the cup. 3/8" shell thickness would probably be ok...
or we could just use a normal cup and bb and a little judgment. the
only bb i've ever had thread problems with was one where the threads
were "loose" from factory. manufacturer clearly aiming for ease of
assembly - or preempting having the lbs "help" the threads by loosening
them up with a tap. either way, loose threads like this do indeed fret,
and relatively fast, especially on an aluminum bb. tight threads fret
also, but so slow it's glacial. no prizes for guessing which side of
the tolerance scale jobst has his bb's.

Quoted message said:

if locktite is liberally used then no fretting occurs. or am I
repeating myself?

repeating yourself. you're right, but wrong because any technical
advance post 1950 is not acknowledged or allowed around here.

Quoted message said:

I haven't used vice grips on an aluminum shimano BB: does the BB
easily deform?

youbetcha!

Quoted message said:

I guess it doesn't matter as the unit was design as
disposable.

a proper tool only costs a few bucks - less than the vice grips.

Quoted message said:

datakoll? said:

Quoted message said:

Because, bicycles have survived with this crude attachment for many
years, no one is stepping up to change the BB shell diameter (it is
too small) or change the face of it (it should be conical).

Quoted message said:

a conically faced BB cup? and where would the conical face be
formed? as the threaded conical face or...?

Quoted message said:

if Loctite is liberally used then no fretting occurs. or am I
repeating myself?

I suggest you put a tandem left crank (right hand thread) on your
bicycle and see if you can keep it from loosening.

why don't /you/ do that? you're the engineer. and you're alleging that
henkel/loctite, who have poured millions of dollars and decades of
research into this stuff, don't know their business! since you've
evidently never used cyanoacrylates, it's time to do your homework
jobst! show us the results of your research, not your usual
preconceived conclusions! and start the lawsuit!

Quoted message said:

Th forces there
are great enough top make aluminum yield and fret.

be clear jobst - it's relative movement that causes fretting. force
from static loading is insufficient to cause yield. if relative
movement is arrested [with loctite], there is no fretting.

Quoted message said:

Loctite is not as
strong as aluminum and even if it were, the aluminum will yield.

see above. as usual, you're distorting the facts to fit an
underinformed preconception.

Quoted message said:

Quoted message said:

I haven't used vice grips on an aluminum Shimano BB: does the BB
easily deform? I guess it doesn't matter as the unit was design as
disposable.

I guess you missed the crank modification I made to address this
problem after breaking at least one crank per year for more than two
dozen years.

i guess you missed the fact that no decent cranks break at the pedal eye
any more due to better metallurgy. rather than bleat about something
that "should" be adopted, instead recognize that it's unnecessary. if
it were still necessary and you still wanted to prove efficacy, make
this mod to an old 70's campy record crank and we'll follow your progress.

Quoted message said:

http://www.chiark.greenend.org.uk/~damerell/bikes/brandt-cranks.jpg

I haven't even inspected a crank since I made this modification a few
years ago.

how utterly illogical! "i made this mod, but never bothered to check to
see if it worked." complete nonsense.

Quoted message said:

It simulated a pedal spindle with a 90° conical taper.
The split allows it to be positioned in the thread relief and
tightening it closes it like a collet on the spindle. The crank in
the foreground shows the fretting erosion that occurs.

http://pardo.net/bike/pic/fail-001/FAIL-016.html

This picture shows my last crank failure with an arrow on the crack
that goes nearly through that side of the pedal eye.

"behold - i, the great and magnificent narcissus, can save the world!
pay me $24 and grovel at my feet and i'll anoint you with the secret of
eternal crank life! [eternal spoke life $24 extra.]"

fortunately, people that know more than you have solved the problem for
real. but maybe if you changed your story a little, you could claim the
credit for their efforts - like you do with "eliminating" spoke fatigue...

Quoted message said:

Quoted message said:

datakoll? said:

> Because, bicycles have survived with this crude attachment for many
> years, no one is stepping up to change the BB shell diameter (it is
> too small) or change the face of it (it should be conical).
a conically faced BB cup? and where would the conical face be
formed? as the threaded conical face or...?
if Loctite is liberally used then no fretting occurs. or am I
repeating myself?

Quoted message said:

Quoted message said:

I suggest you put a tandem left crank (right hand thread) on your
bicycle and see if you can keep it from loosening.

jim beam said:

why don't /you/ do that? you're the engineer. and you're alleging that
henkel/loctite, who have poured millions of dollars and decades of
research into this stuff, don't know their business! since you've
evidently never used cyanoacrylates, it's time to do your homework
jobst! show us the results of your research, not your usual
preconceived conclusions! and start the lawsuit!

Quoted message said:

Quoted message said:

The forces there
are great enough top make aluminum yield and fret.

indeed.

I have seen home amateur mechanics use loctite to no success whatsoever
on pedal threads. More than once. Check in at your local shop for
confirmation.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971