What causes the knock in my electric hub?

On Aug 23, 12:35*pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six





wrote:
On Aug 23, 2:19*am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22*pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. *In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. *If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. *If they are damaged, they will simply be
replaced. *Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. *Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. *Horizontal
positionining is parallel to (or level with) the horizon or still
water. *With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. *The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. *With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. *It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. *Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,
and, as far as can be determined it has little to do with lubrication.

But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?

Cheers,

John B.

From the shape of the box in which the wheel came, I imagine it was
shipped standing up. Certainly not running for months either, as the
battery was well charged on arrival. Trevor's only talent is
pedontology, foot in mouth disease. -- Andre Jute

On 8/23/2011 6:35 AM, john B. wrote:
I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,
[...]

So if I only ride in the dark, I will not have any issues with bearings
fretting? Good to know.

--
Tºm Shermªn - 42.435731°N, 83.985007°W
I am a vehicular cyclist.

On Aug 23, 12:35*pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six





wrote:
On Aug 23, 2:19*am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22*pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. *In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. *If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. *If they are damaged, they will simply be
replaced. *Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. *Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. *Horizontal
positionining is parallel to (or level with) the horizon or still
water. *With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. *The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. *With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. *It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. *Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,

You have something against nightime couriers? The damage may occur
in less than an hour and heavy bearings are known for this. It has
nothing to do with sunlight or the lack of it.

and, as far as can be determined it has little to do with lubrication.

It's "to do with" a lack of (effective) lubrication. Bearings are not
meant to be static, they are meant to turn and the lubricant choice is
dependant upon temperature, load and angular velocity in service.
Advanced lubricants make it possible that bearings will survive poor
handling, but that does not detract from the facts.


But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?
Vibration from the carriage of the wheel, not it's operation (which
would be fine).

On Aug 24, 4:18*am, Andre Jute wrote:
On Aug 23, 12:35*pm, john B. wrote:





On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six

wrote:
On Aug 23, 2:19*am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22*pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. *In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. *If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. *If they are damaged, they will simply be
replaced. *Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. *Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. *Horizontal
positionining is parallel to (or level with) the horizon or still
water. *With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. *The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. *With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. *It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. *Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,
and, as far as can be determined it has little to do with lubrication.

But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?

Cheers,

John B.

From the shape of the box in which the wheel came, I imagine it was
shipped standing up. Certainly not running for months either, as the
battery was well charged on arrival. Trevor's only talent is
pedontology, foot in mouth disease. * -- Andre Jute- Hide quoted text -

- Show quoted text -

You can manage to be ignorant and obnoxious simultaneously, quite a
feat.

On Tue, 23 Aug 2011 22:55:31 -0500, "T°m Sherm@n"
" wrote:

On 8/23/2011 6:35 AM, john B. wrote:
I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,
[...]

So if I only ride in the dark, I will not have any issues with bearings
fretting? Good to know.

Only if you have a theory about it
Cheers,

John B.

On Tue, 23 Aug 2011 22:49:03 -0700 (PDT), thirty-six
wrote:

On Aug 23, 12:35*pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six





wrote:
On Aug 23, 2:19*am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22*pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. *In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. *If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. *If they are damaged, they will simply be
replaced. *Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. *Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. *Horizontal
positionining is parallel to (or level with) the horizon or still
water. *With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. *The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. *With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. *It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. *Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,

You have something against nightime couriers? The damage may occur
in less than an hour and heavy bearings are known for this. It has
nothing to do with sunlight or the lack of it.

Interesting. the bearings we had the problems with were on a 500 KW
generator. We were running a 750 kw generator as primary power and the
500 kw units were standby only. It took nearly 6 months, just sitting
there, for the bearings to fret enough to vibrate.

and, as far as can be determined it has little to do with lubrication.

It's "to do with" a lack of (effective) lubrication. Bearings are not
meant to be static, they are meant to turn and the lubricant choice is
dependant upon temperature, load and angular velocity in service.
Advanced lubricants make it possible that bearings will survive poor
handling, but that does not detract from the facts.

Bearings don't fret if they are constantly rotated, regardless of the
lubrication. You can spin a dry ball bearing with compressed air until
it turns blue without a sign of fretting.


But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?
Vibration from the carriage of the wheel, not it's operation (which
would be fine).
Cheers,

John B.

On Aug 24, 1:05*pm, john B. wrote:
On Tue, 23 Aug 2011 22:49:03 -0700 (PDT), thirty-six





wrote:
On Aug 23, 12:35 pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six

wrote:
On Aug 23, 2:19 am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22 pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. If they are damaged, they will simply be
replaced. Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. Horizontal
positionining is parallel to (or level with) the horizon or still
water. With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,

You have something against nightime couriers? * The damage may occur
in less than an hour and heavy bearings are known for this. *It has
nothing to do with sunlight or the lack of it.

Interesting. the bearings we had the problems with were on a 500 KW
generator. We were running a 750 kw generator as primary power and the
500 kw units were standby only. It took nearly 6 months, just sitting
there, for the bearings to fret enough to vibrate.

You like to put the cart before the horse, I see.

and, as far as can be determined it has little to do with lubrication.

It's "to do with" a lack of (effective) lubrication. *Bearings are not
meant to be static, they are meant to turn and the lubricant choice is
dependant upon temperature, load and angular velocity in service.
Advanced lubricants make it possible that bearings will survive poor
handling, but that does not detract from the facts.

Bearings don't fret if they are constantly rotated, regardless of the
lubrication. You can spin a dry ball bearing with compressed air until
it turns blue without a sign of fretting.

I've no desire to do that.



But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?
Vibration from the carriage of the wheel, not it's operation (which
would be fine).

Cheers,

John B.- Hide quoted text -

- Show quoted text -

On Wed, 24 Aug 2011 05:59:28 -0700 (PDT), thirty-six
wrote:

On Aug 24, 1:05*pm, john B. wrote:
On Tue, 23 Aug 2011 22:49:03 -0700 (PDT), thirty-six





wrote:
On Aug 23, 12:35 pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six

wrote:
On Aug 23, 2:19 am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22 pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs. In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. If they are damaged, they will simply be
replaced. Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. Horizontal
positionining is parallel to (or level with) the horizon or still
water. With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,

You have something against nightime couriers? * The damage may occur
in less than an hour and heavy bearings are known for this. *It has
nothing to do with sunlight or the lack of it.

Interesting. the bearings we had the problems with were on a 500 KW
generator. We were running a 750 kw generator as primary power and the
500 kw units were standby only. It took nearly 6 months, just sitting
there, for the bearings to fret enough to vibrate.

You like to put the cart before the horse, I see.

How so?

and, as far as can be determined it has little to do with lubrication.

It's "to do with" a lack of (effective) lubrication. *Bearings are not
meant to be static, they are meant to turn and the lubricant choice is
dependant upon temperature, load and angular velocity in service.
Advanced lubricants make it possible that bearings will survive poor
handling, but that does not detract from the facts.

Bearings don't fret if they are constantly rotated, regardless of the
lubrication. You can spin a dry ball bearing with compressed air until
it turns blue without a sign of fretting.

I've no desire to do that.



But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?
Vibration from the carriage of the wheel, not it's operation (which
would be fine).

Cheers,

John B.- Hide quoted text -

- Show quoted text -
Cheers,

John B.

On 8/21/2011 5:48 PM, "T°m Sherm@n" wrote:
On 8/21/2011 10:32 AM, thirty-six aka Trevor Jeffrey wrote:
On Aug 21, 6:31 am, Andre wrote:
With only about 50 klicks on it, my 8FUN electric hub has developed a
knock. It happens once per revolution. It is as yet small but
definite. It appears to be a double knock. It doesn't happen unless
there is some weight on the front wheel, such as just pressing down on
the handlebars as I walk the bike. The fit and tightness of the axle
and anti-rotation washers in the fork have been checked, also the
spokes and the headset and are all good.

What you think it is?

Something beyond your investigative skills.

Not very helpful, but funny.


And it's Andre, so that makes it fair.

On Aug 25, 1:02*am, john B. wrote:
On Wed, 24 Aug 2011 05:59:28 -0700 (PDT), thirty-six



wrote:
On Aug 24, 1:05 pm, john B. wrote:
On Tue, 23 Aug 2011 22:49:03 -0700 (PDT), thirty-six

wrote:
On Aug 23, 12:35 pm, john B. wrote:
On Tue, 23 Aug 2011 00:46:11 -0700 (PDT), thirty-six

wrote:
On Aug 23, 2:19 am, john B. wrote:
On Mon, 22 Aug 2011 13:41:42 -0700 (PDT), thirty-six

wrote:
On Aug 22, 8:22 pm, Chalo wrote:
thirty-six wrote:

john B. wrote:

A somewhat belated response but I have the same problem with my front
wheel - a click each revolution with weight applied. Additionally
weaving the bike back and forth across the road indicates that the
problem is only on the L.H. side. I strongly suspect either a bad ball
or a scored race in the front hub.

Andre's original description does seem to fit the idea of a
contaminated bearing or faulty ball found with economy hubs.. In both
cases it is as well to clean out the hubs to remove any swarf or
possibly identify a dud ball. If you have new graded balls, swap them
in after clearing out the muck.

Andre's hub will almost certainly be equipped with industrial sealed
cartridge bearings. If they are damaged, they will simply be
replaced. Probably with some nice German or Swedish-made units, if I
know Andre.

Chalo

It's highly speculative but it is not beyond the bounds of belief that
the wheel was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting.
Oh dear. Is this the fault of the eco wheel supplier, or are they
just doing their best without a suitably qualified engineer?

Errr.... how's that? If the axle is vertical there are about 10 little
balls supporting the wheel; if horizontal, about half that.

Cheers,

John B.

It has nothing to do with your perception of the number of balls in
contact. Vertical positioning links the sky to the ground. Horizontal
positionining is parallel to (or level with) the horizon or still
water. With the axle in the vertical position the balls will
oscillate very fractionally and displace the lubricant between
themselves and the races. The bearing surfaces are then dry and the
chatter will cause fatigue failure in the races at the point of the
ball contact. With the axle in the horizontal position, it is not
loaded by the weight of the wheel and the axle is free to turn. It is
the free turning of the axle to the wheel during carriage which
continues to lubricate the bearing and failure is avoided. Injury
caused by incorrect bearing carriage has been known for over 40
years.

I hate to poke holes in your theories but I have a little experience
with fretted bearings and it is not a process that happens over night,

You have something against nightime couriers? The damage may occur
in less than an hour and heavy bearings are known for this. It has
nothing to do with sunlight or the lack of it.

Interesting. the bearings we had the problems with were on a 500 KW
generator. We were running a 750 kw generator as primary power and the
500 kw units were standby only. It took nearly 6 months, just sitting
there, for the bearings to fret enough to vibrate.

You like to put the cart before the horse, I see.

How so?



and, as far as can be determined it has little to do with lubrication.

It's "to do with" a lack of (effective) lubrication. Bearings are not
meant to be static, they are meant to turn and the lubricant choice is
dependant upon temperature, load and angular velocity in service.
Advanced lubricants make it possible that bearings will survive poor
handling, but that does not detract from the facts.

Bearings don't fret if they are constantly rotated, regardless of the
lubrication. You can spin a dry ball bearing with compressed air until
it turns blue without a sign of fretting.

I've no desire to do that.

But more to the point you specified that the wheel might have been
"was transported on its side with the stress on the axle and
the mass of the motor nicely vibrating the bearing to cause fretting".
given that this is a new installation it seems highly unlikely that
the wheel would have been transported with the motor running, doesn't
it?
Vibration from the carriage of the wheel, not it's operation (which
would be fine).

Cheers,

John B.- Hide quoted text -

- Show quoted text -

Cheers,

John B.

It is vibration of the bearing (which is not turning) which causes the
fretting leading initially to lubricant displacement and bearing
fatigue. Bearings treated with molybdenum disulphide will likely take
relatively long time before failure from simple vibration. It is
worthy of study if you must store bearings next to a running engine.