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Weird mechanical problem



 
 
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  #11  
Old November 8th 20, 03:32 AM posted to rec.bicycles.tech
John B.[_3_]
external usenet poster
 
Posts: 5,697
Default Weird mechanical problem

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.
--
Cheers,

John B.

Ads
  #12  
Old November 8th 20, 03:50 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 10,538
Default Weird mechanical problem

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 Krygowski
  #13  
Old November 8th 20, 04:31 AM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 5,270
Default Weird mechanical problem

On Saturday, 7 November 2020 21:50:13 UTC-5, 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 Krygowski


To be absolutely certain that it's the pedals, put a different pair on the bike and see if the noise persists. If it does then you know its something other than the pedals.

Like you said, it's weird.

Good luck and please let us know what the noise was.

Cheers
  #14  
Old November 8th 20, 05:49 AM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 4,018
Default Weird mechanical problem

On Sat, 7 Nov 2020 21:21:54 -0500, Frank Krygowski
wrote:

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.


You might not need to take a photo. Take the pedal apart and remove
the balls. Clean off the grease. Roll them down a smooth incline
several times. Look for a bearing that wobbles or follows an
eccentric path. On closer inspection, I would expect a flat spot.

Unlike the bearing cup and spindle, with a flat spot on a ball, it can
take many revolutions before the ball, cup, and spindle align
themselves in exactly the same way.

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.


Next to a washing machine? I think we've been here before with
corrosion damage in a garage with a washing machine.

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.

I think we can probably discount this possibility, but it doesn't hurt
to ask your friend if there's anything volatile and corrosive
(muriatic acid or swimming pool chlorine) stored in the garage. I
also had something similar happen during the 1989 earthquake when a
bottle of vinegar (and a different bottle of sulfuric acid) broke when
they hit the floor. Everything made from steel showed signs of rust.

"Muriatic Acid Rusted Everything In My Shop!!"
https://www.youtube.com/watch?v=pj40G8x2SVY (7:09)

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.


That's a good possibility. However, I can't visualize how an extra
ball would cause the observed symptoms without something else in the
pedal also being damaged.

Good luck.
--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #15  
Old November 8th 20, 04:22 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 9,477
Default Weird mechanical problem

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.
  #16  
Old November 8th 20, 04:26 PM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 5,270
Default Weird mechanical problem

On Sunday, 8 November 2020 10:22:21 UTC-5, 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.


In my studies of chemicals I learned that once an original seal is broken that it's nearly impossible to get an airtight seal again on the package, bottle, can, jar et cetera. Thus it's not a good idea to store anything that has harsh chemicals in it (such as household bleach) in area where a lot of living or sleeping goes on.

Cheers
  #17  
Old November 8th 20, 04:27 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Weird mechanical problem

On 11/7/2020 4:29 PM, Lou Holtman wrote:
Op zaterdag 7 november 2020 om 22:36:48 UTC+1 schreef :
On Saturday, November 7, 2020 at 1:49:58 PM UTC-5, AMuzi wrote:
On 11/7/2020 12:22 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?

Bent pedal spindle is extremely rare. They snap in crashes
but almost never bend.

That leaves a nick or pit in one of the bearing surfaces.
Did you check those in a strong light? At our age a
magnifier is indicated as well.

Did her noise go away after pedal rebuild? From your 1st
paragraph I was thinking seatpost or handlebar/stem noise.

I'd have thought stem noise might have been possible, but I've experienced that
mostly when putting some extra force on the bars. I heard the noise as I rode
beside her on level ground as slow as 10 mph. Also, she said she could feel the
clicks in her feet as they happened. (And yes, I inspected the races carefully.)

She phoned today and said the noise is much, much quieter and still very sporadic, but
still present. Tomorrow she's bringing her bike back, plus her spare pedals.

I think Jay has an interesting idea about the loose bearing cup, although I've
never seen that.

I don't think these pedals were very cheap. She claims her bike was
the second-from-the-top touring bike by Trek, back in the mid-1980s. She did say the
top of the line bike had all sealed bearings, but I'd have thought this bike would have
had good equipment.

The pedals are old, though, and I think she consistently does well over 4000 miles per year.
The bike has toured the Appalachians, the Rockies, etc. etc. I'm sure it deserves new pedals -
but the mechanical weirdness has my curiosity in gear.

- Frank Krygowski



You put in new bearing balls. I think that is the problem. It is like putting on a new chain on a worn cassette. After 40 years the pedals deserve a peaceful retirement.

Lou


I don't think so. Fresh grease with new balls is the
standard regular maintenance practice and doesn't otherwise
present any problem.

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


  #18  
Old November 8th 20, 05:27 PM posted to rec.bicycles.tech
Tom Kunich[_2_]
external usenet poster
 
Posts: 1,318
Default Weird mechanical problem

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?
  #19  
Old November 8th 20, 05:47 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Weird mechanical problem

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.

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


  #20  
Old November 8th 20, 07:52 PM posted to rec.bicycles.tech
Tom Kunich[_2_]
external usenet poster
 
Posts: 1,318
Default Weird mechanical problem

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 rather than compressed between the balls and the race. I assume that Frank will attempt to mislead us.
 




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