Weird mechanical problem

On 11/8/2020 12:52 PM, Tom Kunich wrote:
On Sunday, November 8, 2020 at 8:47:46 AM UTC-8, AMuzi wrote:
On 11/8/2020 10:27 AM, Tom Kunich wrote:
On Saturday, November 7, 2020 at 6:50:13 PM UTC-8, Frank Krygowski wrote:
On 11/7/2020 9:32 PM, John B. wrote:
On Sat, 7 Nov 2020 21:21:54 -0500, Frank Krygowski
wrote:

On 11/7/2020 4:55 PM, Jeff Liebermann wrote:
On Sat, 7 Nov 2020 13:22:27 -0500, Frank Krygowski
wrote:

Yesterday we rode with a friend. At times during the ride, her bike was
making a very loud clicking noise, very sporadically, only while
pedaling. It wasn't synchronized with crank rotation, wheel rotation,
chain rotation or anything else I could spot...

Can I guess(tm)?

Asynchronous noises are usually caused by two or more damaged
components that only make a noise when they come into alignment. If
there was a depression in both the bearing cup and the spindle, that
might produce a clicking noise when the two damaged surfaces come into
alignment. However, that would not explain the rather long time
between clicks. The third part of the puzzle might be single ball
with a flat spot. The time of all three parts to come into alignment
seems about right for a "long" period.

Perhaps I should explain a bit more about the long periods of silence.
They were often much more than fifteen minutes. In fact, we rode for
over an hour before I heard (or at least noticed) the clicks. Granted,
she was usually quite a few feet behind me, but not always.

And the clicks were amazingly loud. Not just a mild "tick tick" - more
like "Wow! What's that noise your bike is making!" - impossible to ignore.

Assuming I'm correct, how could a pedal be damaged when aligned in
three places? Corrosion would be my guess(tm). If the bicycle was
sitting in one place, in a wet environment, with no grease on the
bearings, water could build up around the lowest part of the bearing.

I've seen rusted bearings, rusted cups, and rusted spindles, but I've
never done a post mortem to see if the rusted areas aligned in the
position the pedal was stored. I do exactly what you did, which is
disassemble, clean, replace the balls, grease, and adjust.

Yep. I expect she'll be willing to leave the pedal with me. I'll
disassemble again to re-inspect, just for curiosity. Maybe I can get
some decent photos. But I know good closeup photos of tiny mechanical
parts are not simple.

I have no idea why it would be so tricky to adjust, unless the cup is
out of round or something else is mangled.

Ask the owner if the bicycle was stored in a fixed position for a few
months in a potentially wet environment.

This is one of our best friends. Her bike is very well cared for -
actually pristine. It's stored in an attached (semi-heated) garage.

One possibility has since occurred to me: I counted the balls I removed
(13 & 10 IIRC) and replaced the same numbers (inner and outer), but I
have no guarantee that those numbers were correct. I wonder if (say) the
inner race was short one ball. If the resulting gap between balls
happened to line up with a slight eccentricity on either the pedal axle
or pedal body, it might allow contact where there should be a tiny
clearance.

I can envision such a problem being much worse when the adjustment was
as bad as this one was, and becoming much reduced but not cured with
proper adjustment. (But who knows how it ever came out of adjustment...)

I'll report further after another disassembly.

The so called "rule of thumb" for loose balls in a bearing is 1 less
then the maximum that will fit. Which has worked well in my
experience.
It's what I usually do. This time I counted the old ones. I'll see if
that was a mistake.

Frank, you don't count them. You fill the bearing race and then remove one. This has always been the way for loose bearings. I thought you were a mechanical engineer?

That's not correct.
It's an often useful rule of thumb where bearing counts are
high, such as a headset. Even there it's not dispositive.

Where the manufacturer's size and count are unknown errors
abound, both over and under, which can lead to destructive
errors.

I'm afraid you've lost me Andrew, I assume you KNOW what size balls are supposed to be inserted and that the open bearing races are properly made. I have never seen say, a bottom bracket free bearing system in which you could "overfill" the races. If you ever used old open bearing heavy shop machine tools that was also the way they were designed. These are taken directly off of a chart that left you with a particular size ball filling the races completely which would cause excessive friction from ball to ball unless you removed one ball. (https://www.amroll.com/internal-clea...practices.html) Grease is an oil that is combined with a gel. So that the weight of this is important so that you do not have excessively heavy grease allowing the oil to fill any clearance between the ball and the race. It is also necessary not to have the bearing turning when it is greased so that turning it after the application of grease allows any excess gel/oil to be pushed out of the way r
ather than compressed between the balls and the race. I assume that Frank will attempt to mislead us.



Anyone familiar with bicycle service will affirm that
consumers regularly add too many balls to hubs and crank
bearings which is often destructive, especially when
combined with 'crank that thing down tight' instead of a
bearing adjustment.

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

On Sun, 8 Nov 2020 07:22:15 -0800, sms
wrote:

On 11/7/2020 8:49 PM, Jeff Liebermann wrote:

snip

Drivel: I also had some rust damage when storing my bicycle in a
spare bedroom over one winter. It wasn't condensation that created
the problem, but rather a bottle of sulfuric acid in the same closet.
I got the clue when all the coat hangers, metal buttons, and other
metal things in the closet began to corrode.

Yeah, I stopped storing hydrochloric acid in a bedroom closet because of
the same problem. Other than rust, a bedroom closet is the obvious place
to store acid.

I thought this might be a good time to visit my collection of
hazardous, toxic, and dangerous substances in the closet:
http://www.11junk.com/jeffl/pics/drivel/index.html#Red-Fuming-Nitric.jpg
That's 94% red fuming nitric acid. The bottle is less than half full
and probably 45 years old. However, I did find some problems.

1. The cardboard box in which the bottle and styrofoam shock absorber
were stored crumbled to dust when I touched it. Looks like the acid
is still leaking. The rubber bottle cap also looks like it mighte be
time for a replacement.

2. Despite warning labels with arrows and "this side up", I managed
to store the bottle on its side. This is a really bad idea as changes
in temperature and atmospheric pressure will cause the acid to leak
out through the cap. That would explain the relatively small amount
of acid left in the bottle. I'm fairly sure there was more. I know
it was stored in the correct position when the fumes rusted my bicycle
and clothes, but not so sure if I put it back that way. I think what
kept it from corroding a repeat performance was a plastic storage box
and multiple plastic bags.

https://store.interstateproducts.com/products/Acid-Corrosive-Cabinets
One of these in 12 gallon size will burn a big hole in my wallet.

Mention of this posting entitles the reader to correctly accuse me of
being a dangerous and sloppy idiot. Try not to enjoy yourself too
much.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 8 Nov 2020 10:52:29 -0800 (PST), Tom Kunich
wrote:
(https://www.amroll.com/internal-clea...practices.html)

Could you point me to where on the Amroll web page or in your
explanation I might find a method of calculating how many balls are
considered optimum for a given size ball bearing? Unless I missed
something, ball count was what we were discussing.

Incidentally, radial and axial clearances in bearings are commonly
called "play" or "slop" and have little to do with the number of balls
used in typical bicycle bearings.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 11/7/2020 1:22 PM, Frank Krygowski wrote:
Yesterday we rode with a friend. At times during the ride, her bike was
making a very loud clicking noise, very sporadically, only while
pedaling. It wasn't synchronized with crank rotation, wheel rotation,
chain rotation or anything else I could spot. Gear selection didn't seem
to matter. It would pop up for a few seconds then go completely silent
for very long periods. Sometimes they were sort of double clicks, mostly
single clicks.

We stopped, I inspected everything and found nothing wrong except her
left pedal had lots of bearing slack. Her bike is a Trek touring bike,
nearly all original, and these are SR pedals from the 1980s with
replaceable balls. I offered to work on it when we got back to my house.

I put the pedal in the bench vise, removed all the 1/8" balls, cleaned
and inspected and saw nothing wrong except terribly loose cone
adjustment. Put in new 1/8" balls with new grease and adjusted the
bearings.

Here's the weird part. Adjustment was very touchy, going from slightly
loose everywhere to slightly binding at just one spot. At that spot, the
resistance or drag would appear, then disappear as I rotated the spindle
back and forth through maybe 30 degrees.

The resistance would not be enough to really interfere with pedaling -
it was very easily overcome with my finger and thumb - but it's just not
right. And I'm having trouble visualizing what could be going on in
there. It's not like I haven't done this before!

I'm sure a bike shop would say "Just put in new pedals," since the labor
I already put in would be more expensive. And she has a spare set. She
just likes these better, so I'd like to get them fixed for her.

Any clues what might be wrong?

I finally took the time to dig into the offending pedal from my friend's
bike. Her bike now has a different set of pedals on it. The bike is
quiet and she's happy.

My work on the pedal at the end of our ride together apparently
eliminated the loud clicking noise we heard. She took it for a ride the
next day and said it was much, much better.

But what had really confused me was, after cleaning, inspecting,
greasing but before reinstalling, this pedal had a slight sticking or
hitch I could feel when rotating the pedal axle by hand. That was
despite my best efforts at adjusting the cone. But that was absent, or
almost completely absent, after she had ridden the bike perhaps 35
miles, then brought it back to trade pedals.

So even though this is now her spare set of pedals and seemed to be
turning smoothly, I tore it down again. The number of balls was correct.
(I even tried adding one ball to be sure, but I had to remove it.) There
were no loose cup inserts. The pedal cage is riveted or cast (I can't be
sure which) to the aluminum pedal body and that attachment seems secure,
as do the toe clips and pedal reflectors. Adjustment is still very
touchy. I've got maybe half a millimeter radial play at the outer
bearing, which is more than I would normally tolerate. But if I do
adjust it for zero or near-zero slack, it feels rough.

After high magnitude inspection with a loupe, I can say the outer cone
looks bad. The surface on which the balls roll is not a nice uniform
polished track. Instead the track is indistinct, apparently a bit
eccentric and the cone looks microscopically lumpy. I'm guessing that's
the source of all the problems, although the decibel level of the
clicking noise still astonishes me.

I did note her chain is worn, and I suggested it's time for a major lube
job and tuneup - hubs, bottom bracket and headset re-lube. She's
promised to have that done in the dead of winter. We'll see if anything
else is uncovered when that happens.

--
- Frank Krygowski

On Sunday, November 8, 2020 at 2:16:21 PM UTC-8, wrote:
On Sun, 8 Nov 2020 10:52:29 -0800 (PST), Tom Kunich
wrote:
(https://www.amroll.com/internal-clea...practices.html)

Could you point me to where on the Amroll web page or in your
explanation I might find a method of calculating how many balls are
considered optimum for a given size ball bearing? Unless I missed
something, ball count was what we were discussing.

Incidentally, radial and axial clearances in bearings are commonly
called "play" or "slop" and have little to do with the number of balls
used in typical bicycle bearings.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
It appears that my messages aren't loading properly again so I'll repeat this:

Bearing races are designed specifically for a specific ball size. The thickness of the races are set so that they can have just the right number of bearings to give the proper number. If they use free bearings (which is rare these days) you simply fill the races with all of the bearings that will fit and then remove one. This allows the bearings to revolve without excessive friction against one another and to not get enough slack in the bearings so that one with fall out. Every great once in awhile you can find a caged bearing that has broken its cage and has dumped all of the bearings out into the nearest space if any is available. If you have a bottom bracket caged bearing do this the bearing will usually fall out of the drain hole in the bottom of the BB. But it is EXTREMELY noticeable since the crank rocks to either side making perfectly awful noises.

Come on, Jeff, this was machine shop 101.

On Sunday, November 29, 2020 at 5:05:33 PM UTC-6, wrote:
Every great once in awhile you can find a caged bearing that has broken its cage and has dumped all of the bearings out into the nearest space if any is available.

I think I missed Machine Shop 101, but I've never seen a ball bearing cage that was the thing that kept the balls in the races. In my (admittedly limited) experience, most of the high-end bearings (eg, Shimano Ultegra) do not have cages, and those bearings with cages (eg, Motobecane bottom bracket) perform fine after substitution with loose balls. It would seem the races would have to be quite loose to permit the bearing balls to escape.

On Sunday, November 29, 2020 at 4:50:42 PM UTC-8, Steve Weeks wrote:
On Sunday, November 29, 2020 at 5:05:33 PM UTC-6, wrote:
Every great once in awhile you can find a caged bearing that has broken its cage and has dumped all of the bearings out into the nearest space if any is available.
I think I missed Machine Shop 101, but I've never seen a ball bearing cage that was the thing that kept the balls in the races. In my (admittedly limited) experience, most of the high-end bearings (eg, Shimano Ultegra) do not have cages, and those bearings with cages (eg, Motobecane bottom bracket) perform fine after substitution with loose balls. It would seem the races would have to be quite loose to permit the bearing balls to escape.

TK uses a lot of Italian BBs that have a tendency to unscrew, so maybe his BB unscrewed so far that he was shedding balls out of a broken retainer. Mine never loosened that far because it means your crank is basically banging around in the BB.

-- Jay Beattie.

On 11/29/2020 6:50 PM, Steve Weeks wrote:
On Sunday, November 29, 2020 at 5:05:33 PM UTC-6, wrote:
Every great once in awhile you can find a caged bearing that has broken its cage and has dumped all of the bearings out into the nearest space if any is available.

I think I missed Machine Shop 101, but I've never seen a ball bearing cage that was the thing that kept the balls in the races. In my (admittedly limited) experience, most of the high-end bearings (eg, Shimano Ultegra) do not have cages, and those bearings with cages (eg, Motobecane bottom bracket) perform fine after substitution with loose balls. It would seem the races would have to be quite loose to permit the bearing balls to escape.


You are correct.
The bearing geometry is what it is, retainers facilitate
faster assembly. Retainers can also be designed to run with
fewer than ideal bearing count, those being cost benefits to
the manufacturer to a moderate or severe extent.

Examples include Campagnolo classic crank retainers, much
copied to good effect, with eleven balls. Retainers exist
with nine and even the REG nylon retainer with seven. They
all fit equally well but longevity may suffer.

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

On Sun, 29 Nov 2020 15:05:30 -0800 (PST), Tom Kunich
wrote:

It appears that my messages aren't loading properly
again so I'll repeat this:
(...)

Frank mentioned several times in this thread that he's working with
loose ball bearings. There were no sealed or caged bearing involved.

Come on, Jeff, this was machine shop 101.

That's odd. Your traditional implied insult normally appears at the
beginning of your message. This time it appeared at the end. Is
something wrong?

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sunday, November 29, 2020 at 4:50:42 PM UTC-8, Steve Weeks wrote:
On Sunday, November 29, 2020 at 5:05:33 PM UTC-6, wrote:
Every great once in awhile you can find a caged bearing that has broken its cage and has dumped all of the bearings out into the nearest space if any is available.
I think I missed Machine Shop 101, but I've never seen a ball bearing cage that was the thing that kept the balls in the races. In my (admittedly limited) experience, most of the high-end bearings (eg, Shimano Ultegra) do not have cages, and those bearings with cages (eg, Motobecane bottom bracket) perform fine after substitution with loose balls. It would seem the races would have to be quite loose to permit the bearing balls to escape.

Perhaps you'd like to inform me how you think that flat ball bearing races could possibly be loaded with more than about 1/3 of a full load of balls?

Steve, you certainly must have missed Machine Shop. And you must not have worked on many bicycle bottom brackets. That you've never seen a broken cage obviously means that they never occur correct? Admittedly that is rare but it most certainly happens. Loose ball bearings in bicycle bottom brackets are in tapered bearing races. Else you could not add and subtract a full load. You could not put the balls in a standard caged roller unless it used far less than a full load. This also greatly effects the life of the bearing since the area in a bottom bracket is fixed around the size of the old square taper tapered races which carried probably three times the number of bearings reducing wear a great deal. Caged bearing could work if the size of the BB has been increased enough so that the bearings are large enough to accept the increased bearing loads from fewer bearings and that is why they have largely changed over to external bearings. But then they screw it all up by inserting a 30 mm shaft into this which again shrinks the bear races and bearings down to the size in which the races flex under the loads wearing them out in less time that normal. This is why Campy and Shimano have retained external bearings and 24 mm shafts.

Because of the loads on pedals, the bearings are normally caged rollers instead of balls. This allows them to use something like #5 grease that can maintain long term lubrication which not allowing external dirt into the bearings. The reason that the cages are used on rollers which run in flat races is so that the grease has a place to be safely tucked away since if that heavy a grease was in the races with a large load of rollers it would break the races.

This crap isn't rocket science but neither is it simple mechanical engineering. Bicycles have been under development for 140 years and each year something has received real improvement. Waterford makes steel racing bikes weight competitive with carbon fiber and Di2 shifts so rapidly and quietly that unless it is under a heavy load of climbing you can't even tell when it has shifted. Too bad that they have gone absolutely nuts on the numbers of speeds. I'm quite sure that even the pros don't use that full gear ratios and end up using perhaps 9 just as in the early 2000's