Sudden BB disintegration

Ron-<< When your BB starts wobbling, it's time to tighten up the thing
slightly. Once. >><BR><BR>

Sort of. Cups generally don't loosen if properly installed. If the BB has been
fine, and then all of the sudden it is loose, probably cuz a BB cup or spindle
race has gone south, created more play=loose BB.

I would take the arms off, feel how smooth or not the BB spindle is. If smooth,
adjust and see, if not, remove and examine.

All above for cup and ball BBs.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"

On 23 Jan 2005 15:25:44 GMT, [email hidden] (Qui si parla

Campagnolo ) may have said:

Ron-<< When your BB starts wobbling, it's time to tighten up the thing
slightly. Once. >><BR><BR>

Sort of. Cups generally don't loosen if properly installed.

I think he means that the balls and cups had been degraded to the
point where the surfaces which bear the major load are toasty, making
the assembly sloppy.

Quoted message said:

If the BB has been
fine, and then all of the sudden it is loose, probably cuz a BB cup or spindle
race has gone south, created more play=loose BB.

Yeah, I think that's what he meant.

Quoted message said:

I would take the arms off, feel how smooth or not the BB spindle is. If smooth,
adjust and see, if not, remove and examine.

All above for cup and ball BBs.

His plan to rotate 90 degrees and put the load on the least-worn part
of the BB assembly probably had the best chance of success among the
possible not-really-fixing-it actions, but in the long run, I think
he'd be better off with a sealed BB installed with lots of grease.
Either that, or he needs a place like the one I know not too far from
here where used bikes of that ilk can be reliably had for $25.
They're mostly not in bad shape.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

If the CUPS are going, no amount of crank relocation will matter. Duh.

- -

"May you have the winds at your back,
And a really low gear for the hils!"

Chris Zacho ~ "Your Friendly Neighborhood Wheelman"

Chris'Z Corner
http://www.geocities.com/czcorner

On Sun, 23 Jan 2005 13:12:59 -0500, [email hidden] (Chris

Zacho 'The Wheelman') may have said:

If the CUPS are going, no amount of crank relocation will matter. Duh.

Yeah, that's right, he was going to swap the cranks to a different
clock position on the spindle, but I was thinking in terms of the fact
that the slop would also put the cup into a different rotational
position after reassembly, presenting a less toased face in the
load-bearing areas. It went crunch! first. Probably just as well,
really.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Werehatrack said:

On Sun, 23 Jan 2005 13:12:59 -0500, [email hidden] (Chris

Zacho 'The Wheelman') may have said:

If the CUPS are going, no amount of crank relocation will matter. Duh.

Yeah, that's right, he was going to swap the cranks to a different
clock position on the spindle, but I was thinking in terms of the fact
that the slop would also put the cup into a different rotational
position after reassembly, presenting a less toased face in the
load-bearing areas. It went crunch! first. Probably just as well,
really.

I had a friend in college who ran his junker through untold noises and
clunking, until the face of one of his BB cups fell off - he had ground
clear through the cup! Either the threads were garbage or the failure
had munged them, 'cause we had to use a carbide rod saw to cut the cup
out. The whole bike wasn't worth the effort, but it was a sentimental
thing (and a kind of crazy challenge).

You *can* go too far with avoiding BB maintenance.

Mark Janeba

In article <[email hidden]>, Ron Hardin

Quoted message said:

When your BB starts wobbling, it's time to tighten up the thing slightly.
Once.

When it starts klunking, I have learned not to tighten it, as it will
disintegrate shortly. Instead, reverse the crank arms by 180 degrees, so
that an unworn part of the spindle is used. Indeed, this doubles the
lifetime of the thing.

My plan was, the next time, to rotate the cranks 90 degrees, and then
another 180 after that, but the ``next time'' the BB gave one revolution
of klunk warning and then disintegrated, leaving a walk home. Fortunately,
unlike most walks home, both tires were fine and so the bike actually
rolled easily.

I imagine, but I have not looked, the BB being encased in road salt and ice
at the moment, that the race has worn completely through. Once a bearing
takes
a pioneering new route, it's all over. The klunk is the bearing making up
its mind about this possibility.

So it's time to replace the power train again. The chain indeed is on
the outer limits of the chainwheel teeth and pops off on a really hard
start.

I hate to put on a new power train in road-salt season though.

Maybe go to the backup Huffy for a couple months, rather than just the few
days it takes to gather up parts for the thing.

Yeah, there's no better time to demolish a BB than during winter (been
there myself). Why not just pop in a new *cartridge* BB for the time
being and leave the rest until spring? A Shimano UN-73 or UN-52 can be
had cheaply; then you won't have to resort to the Huffy!

Luke

You have a funny idea of the meaning of "sudden".

Bad Idea said:

You have a funny idea of the meaning of "sudden".

It ran another 4k miles with the reversed cranks, no wobble
or klunking. That is, the original klunking is produced by
the spindle, not the races, and removing the wear on the spindle
from the pressure that produced it solved the problem.

This avoids a ``premature'' complete power train replacement and
accompanying greasy hands and hammered thumbs, more or less doubling
the lifetime of the whole power train.

I was just saying, that the second time it wears to the point that
bearings pioneer new paths and produce warning klunks, the warning
(in this case, anyway) is just one revolution, not an entire trip
home where you can do something about it.

You may like disassembling your bike (you will outgrow it) but I don't,
particularly. I just ride them, given my choice. If it ain't broke,
don't fix it.
--
Ron Hardin
[email hidden]

On the internet, nobody knows you're a jerk.