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  #11  
Old June 1st 16, 06:39 PM posted to rec.bicycles.tech
ian field
external usenet poster
 
Posts: 1,008
Default Sealed Bearings



"John B." wrote in message
...
On Tue, 31 May 2016 21:38:48 +0100, "Ian Field"
wrote:



wrote in message
...
With all the bikes I have I also have a bike for which I built the
wheels
on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me
while
I was not in the best of health I rebuilt the wheels with new balls and
Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who
make
the modern Campy hubs etc.) These wheels have sealed bearings. These
sort
of bothered me when I saw them because of the drag of the seals. You can
tell simply spinning the wheels in a stand. But I imagined that with the
weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in fact
you CAN feel the difference between the open bearings and the sealed. It
does coast much further and with less noise.



If you mean regular bearings like the ones used for gear box shafts;
there's
a choice between shielded and oil seal bearings.

The oil seal type have noticeable friction, while AFAIK: the shielded type
just have a stainless steel shield that doesn't have any actual contact
with
the inner ring.

The oil seal type are only unavoidable if you need to contain oil.
The shielded type are OK with grease, but not 100% at keeping road grit
out.


You over simplify, There are basically three types of cartridge
bearing. Plain (open, no seals or shields), Shielded and Sealed.


Evidently not simple enough for you - the discussion was not about open
bearings.

Ads
  #12  
Old June 2nd 16, 03:46 AM posted to rec.bicycles.tech
John B.[_6_]
external usenet poster
 
Posts: 2,202
Default Sealed Bearings

On Wed, 1 Jun 2016 18:39:42 +0100, "Ian Field"
wrote:



"John B." wrote in message
.. .
On Tue, 31 May 2016 21:38:48 +0100, "Ian Field"
wrote:



wrote in message
...
With all the bikes I have I also have a bike for which I built the
wheels
on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me
while
I was not in the best of health I rebuilt the wheels with new balls and
Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who
make
the modern Campy hubs etc.) These wheels have sealed bearings. These
sort
of bothered me when I saw them because of the drag of the seals. You can
tell simply spinning the wheels in a stand. But I imagined that with the
weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in fact
you CAN feel the difference between the open bearings and the sealed. It
does coast much further and with less noise.


If you mean regular bearings like the ones used for gear box shafts;
there's
a choice between shielded and oil seal bearings.

The oil seal type have noticeable friction, while AFAIK: the shielded type
just have a stainless steel shield that doesn't have any actual contact
with
the inner ring.

The oil seal type are only unavoidable if you need to contain oil.
The shielded type are OK with grease, but not 100% at keeping road grit
out.


You over simplify, There are basically three types of cartridge
bearing. Plain (open, no seals or shields), Shielded and Sealed.


Evidently not simple enough for you - the discussion was not about open
bearings.


No it wasn't, but then, you are so accustomed to shouting "****wit" I
thought it best to be overly cautious and cover all possible points of
contention, as it is obvious from the "Great V-brake Discussion" that
your mechanical abilities is, well, rather limited.

Obviously it was a mistake as you still shout and scream.
--
cheers,

John B.

  #13  
Old June 2nd 16, 06:40 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Sealed Bearings

On 2016-06-01 17:55, Phil W Lee wrote:
Joerg considered Wed, 01 Jun 2016
10:02:11 -0700 the perfect time to write:

On 2016-05-29 20:03, Frank Krygowski wrote:
On 5/29/2016 2:40 PM, wrote:
With all the bikes I have I also have a bike for which I built the
wheels on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me
while I was not in the best of health I rebuilt the wheels with new
balls and Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who
make the modern Campy hubs etc.) These wheels have sealed bearings.
These sort of bothered me when I saw them because of the drag of the
seals. You can tell simply spinning the wheels in a stand. But I
imagined that with the weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in
fact you CAN feel the difference between the open bearings and the
sealed. It does coast much further and with less noise.

Has anyone else noticed this?

FWIW, of my four most-ridden bikes, two have sealed bearing hubs and two
do not. I can't tell the difference in the hubs. Perhaps it's because
the bikes are quite different; but even on the workstand, I haven't
noticed any difference.


No wonder. Just imagine what would happen if only 2% of a sporty rider's
200W would be lost in the bearings. That would come to 1W dissipation
per bearing and they'd become very toasty. Yet they never do.


I think you'll find that a typical aluminium bicycle wheel hub will
VERY easily dissipate quite a few watts - probably well into double
digits - without getting in the least bit toasty, with only the normal
airflow to cool it.



I was thinking about the material used in the seals. On MTB that is
usually rubber and on road bikes often some sort of fiber. Very small,
so the seal itself would likely burn up.


It has more surface area than heat sinks used for integrated circuits
which need to dissipate tens of watts, and FAR better airflow than you
find inside most electronic equipment as well.

And 2% of 200 is 4, by the way.


But you have four bearings, so 1W each.

--
Regards, Joerg

http://www.analogconsultants.com/
  #14  
Old June 2nd 16, 07:16 PM posted to rec.bicycles.tech
ian field
external usenet poster
 
Posts: 1,008
Default Sealed Bearings



"John B." wrote in message
...
On Wed, 1 Jun 2016 18:39:42 +0100, "Ian Field"
wrote:



"John B." wrote in message
. ..
On Tue, 31 May 2016 21:38:48 +0100, "Ian Field"
wrote:



wrote in message
...
With all the bikes I have I also have a bike for which I built the
wheels
on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me
while
I was not in the best of health I rebuilt the wheels with new balls
and
Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who
make
the modern Campy hubs etc.) These wheels have sealed bearings. These
sort
of bothered me when I saw them because of the drag of the seals. You
can
tell simply spinning the wheels in a stand. But I imagined that with
the
weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in
fact
you CAN feel the difference between the open bearings and the sealed.
It
does coast much further and with less noise.


If you mean regular bearings like the ones used for gear box shafts;
there's
a choice between shielded and oil seal bearings.

The oil seal type have noticeable friction, while AFAIK: the shielded
type
just have a stainless steel shield that doesn't have any actual contact
with
the inner ring.

The oil seal type are only unavoidable if you need to contain oil.
The shielded type are OK with grease, but not 100% at keeping road grit
out.

You over simplify, There are basically three types of cartridge
bearing. Plain (open, no seals or shields), Shielded and Sealed.


Evidently not simple enough for you - the discussion was not about open
bearings.


No it wasn't, but then, you are so accustomed to shouting "****wit" I
thought it best to be overly cautious and cover all possible points of
contention, as it is obvious from the "Great V-brake Discussion" that
your mechanical abilities is, well, rather limited.

Obviously it was a mistake as you still shout and scream.


You're the one that keeps on ranting - and I've seen at least one other
person on the receiving end.

  #15  
Old June 2nd 16, 07:19 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Sealed Bearings

On 6/2/2016 12:40 PM, Joerg wrote:
On 2016-06-01 17:55, Phil W Lee wrote:
Joerg considered Wed, 01 Jun
2016
10:02:11 -0700 the perfect time to write:

On 2016-05-29 20:03, Frank Krygowski wrote:
On 5/29/2016 2:40 PM, wrote:
With all the bikes I have I also have a bike for which
I built the
wheels on old Campy record hub on the back and DuraAce
on the front.

After getting this bike back from a friend who was
saving it for me
while I was not in the best of health I rebuilt the
wheels with new
balls and Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum
(the people who
make the modern Campy hubs etc.) These wheels have
sealed bearings.
These sort of bothered me when I saw them because of
the drag of the
seals. You can tell simply spinning the wheels in a
stand. But I
imagined that with the weight of a person this would be
insignificant.

For the last couple of days I have been riding the old
Look and in
fact you CAN feel the difference between the open
bearings and the
sealed. It does coast much further and with less noise.

Has anyone else noticed this?

FWIW, of my four most-ridden bikes, two have sealed
bearing hubs and two
do not. I can't tell the difference in the hubs.
Perhaps it's because
the bikes are quite different; but even on the
workstand, I haven't
noticed any difference.


No wonder. Just imagine what would happen if only 2% of a
sporty rider's
200W would be lost in the bearings. That would come to 1W
dissipation
per bearing and they'd become very toasty. Yet they never
do.


I think you'll find that a typical aluminium bicycle wheel
hub will
VERY easily dissipate quite a few watts - probably well
into double
digits - without getting in the least bit toasty, with
only the normal
airflow to cool it.



I was thinking about the material used in the seals. On MTB
that is usually rubber and on road bikes often some sort of
fiber. Very small, so the seal itself would likely burn up.


It has more surface area than heat sinks used for
integrated circuits
which need to dissipate tens of watts, and FAR better
airflow than you
find inside most electronic equipment as well.

And 2% of 200 is 4, by the way.


But you have four bearings, so 1W each.



There's nothing new in bearing seals, big selection:

http://www.skf.com/au/products/beari...als/index.html


The seal type is the last part of the bearing number. If you
need tighter sealing or more free running seals, buy a
bearing with a different suffix.

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


  #16  
Old June 3rd 16, 05:28 AM posted to rec.bicycles.tech
James[_8_]
external usenet poster
 
Posts: 6,153
Default Sealed Bearings

On 03/06/16 03:40, Joerg wrote:



I was thinking about the material used in the seals. On MTB that is
usually rubber and on road bikes often some sort of fiber. Very small,
so the seal itself would likely burn up.



I have never seen a fibre "seal" used on any bicycle bearing. All of
the seals I've seen are rubber, and they most certainly do not "burn up".


It has more surface area than heat sinks used for integrated circuits
which need to dissipate tens of watts, and FAR better airflow than you
find inside most electronic equipment as well.

And 2% of 200 is 4, by the way.


But you have four bearings, so 1W each.


I used an on line estimator of bearing losses by SKF some time ago, to
find out what they estimate bearing loses to be for a typical double
sealed cartridge bearing as used in the wheels I had at the time. The
bearings have a rubber seal on both sides. If I remember correctly, the
loses per bearing were in the order of 0.5W at a road speed of 50km/h.
0.1W of that was rolling friction. I.e. sticky grease and friction in
the ball cage. 0.4W was from the seal friction.

So a total of about 1W per wheel at 50km/h. Hardly enough to raise the
bearing temperature by some detectible level above ambient - even if the
bike was stationary and being pedalled on rollers!

--
JS
  #17  
Old June 3rd 16, 08:46 AM posted to rec.bicycles.tech
John B.[_6_]
external usenet poster
 
Posts: 2,202
Default Sealed Bearings

On Thu, 2 Jun 2016 19:16:44 +0100, "Ian Field"
wrote:



"John B." wrote in message
.. .
On Wed, 1 Jun 2016 18:39:42 +0100, "Ian Field"
wrote:



"John B." wrote in message
...
On Tue, 31 May 2016 21:38:48 +0100, "Ian Field"
wrote:



wrote in message
...
With all the bikes I have I also have a bike for which I built the
wheels
on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me
while
I was not in the best of health I rebuilt the wheels with new balls
and
Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who
make
the modern Campy hubs etc.) These wheels have sealed bearings. These
sort
of bothered me when I saw them because of the drag of the seals. You
can
tell simply spinning the wheels in a stand. But I imagined that with
the
weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in
fact
you CAN feel the difference between the open bearings and the sealed.
It
does coast much further and with less noise.


If you mean regular bearings like the ones used for gear box shafts;
there's
a choice between shielded and oil seal bearings.

The oil seal type have noticeable friction, while AFAIK: the shielded
type
just have a stainless steel shield that doesn't have any actual contact
with
the inner ring.

The oil seal type are only unavoidable if you need to contain oil.
The shielded type are OK with grease, but not 100% at keeping road grit
out.

You over simplify, There are basically three types of cartridge
bearing. Plain (open, no seals or shields), Shielded and Sealed.

Evidently not simple enough for you - the discussion was not about open
bearings.


No it wasn't, but then, you are so accustomed to shouting "****wit" I
thought it best to be overly cautious and cover all possible points of
contention, as it is obvious from the "Great V-brake Discussion" that
your mechanical abilities is, well, rather limited.

Obviously it was a mistake as you still shout and scream.


You're the one that keeps on ranting - and I've seen at least one other
person on the receiving end.


Yes, and you might see more.

But one thing you won't see, is me calling someone that is trying to
help me a "****wit".
--
cheers,

John B.

  #18  
Old June 3rd 16, 10:55 AM posted to rec.bicycles.tech
John B.[_6_]
external usenet poster
 
Posts: 2,202
Default Sealed Bearings

On Fri, 3 Jun 2016 14:28:29 +1000, James
wrote:

On 03/06/16 03:40, Joerg wrote:



I was thinking about the material used in the seals. On MTB that is
usually rubber and on road bikes often some sort of fiber. Very small,
so the seal itself would likely burn up.



I have never seen a fibre "seal" used on any bicycle bearing. All of
the seals I've seen are rubber, and they most certainly do not "burn up".


It has more surface area than heat sinks used for integrated circuits
which need to dissipate tens of watts, and FAR better airflow than you
find inside most electronic equipment as well.

And 2% of 200 is 4, by the way.


But you have four bearings, so 1W each.


I used an on line estimator of bearing losses by SKF some time ago, to
find out what they estimate bearing loses to be for a typical double
sealed cartridge bearing as used in the wheels I had at the time. The
bearings have a rubber seal on both sides. If I remember correctly, the
loses per bearing were in the order of 0.5W at a road speed of 50km/h.
0.1W of that was rolling friction. I.e. sticky grease and friction in
the ball cage. 0.4W was from the seal friction.

So a total of about 1W per wheel at 50km/h. Hardly enough to raise the
bearing temperature by some detectible level above ambient - even if the
bike was stationary and being pedalled on rollers!


Could you have used "seal one side" bearings. I have a set of wheels
with cartridge bearings and before I built the wheels I took the hubs
apart and that is what they had. So (I guess) only 1/2W at 50 :-)
--
cheers,

John B.

  #19  
Old June 3rd 16, 12:59 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Sealed Bearings

On 6/2/2016 11:28 PM, James wrote:
On 03/06/16 03:40, Joerg wrote:



I was thinking about the material used in the seals. On
MTB that is
usually rubber and on road bikes often some sort of fiber.
Very small,
so the seal itself would likely burn up.



I have never seen a fibre "seal" used on any bicycle
bearing. All of the seals I've seen are rubber, and they
most certainly do not "burn up".


It has more surface area than heat sinks used for
integrated circuits
which need to dissipate tens of watts, and FAR better
airflow than you
find inside most electronic equipment as well.

And 2% of 200 is 4, by the way.


But you have four bearings, so 1W each.


I used an on line estimator of bearing losses by SKF some
time ago, to find out what they estimate bearing loses to be
for a typical double sealed cartridge bearing as used in the
wheels I had at the time. The bearings have a rubber seal
on both sides. If I remember correctly, the loses per
bearing were in the order of 0.5W at a road speed of 50km/h.
0.1W of that was rolling friction. I.e. sticky grease and
friction in the ball cage. 0.4W was from the seal friction.

So a total of about 1W per wheel at 50km/h. Hardly enough
to raise the bearing temperature by some detectible level
above ambient - even if the bike was stationary and being
pedalled on rollers!


There are bearing shields made of various fibers, usually in
phenolic resin:
http://www.ib-bearings.com/product2.html

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


  #20  
Old June 3rd 16, 05:36 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,345
Default Sealed Bearings

On Sunday, May 29, 2016 at 11:40:18 AM UTC-7, wrote:
With all the bikes I have I also have a bike for which I built the wheels on old Campy record hub on the back and DuraAce on the front.

After getting this bike back from a friend who was saving it for me while I was not in the best of health I rebuilt the wheels with new balls and Campy grease.

I have mostly modern wheelsets from Campy or Fulcrum (the people who make the modern Campy hubs etc.) These wheels have sealed bearings. These sort of bothered me when I saw them because of the drag of the seals. You can tell simply spinning the wheels in a stand. But I imagined that with the weight of a person this would be insignificant.

For the last couple of days I have been riding the old Look and in fact you CAN feel the difference between the open bearings and the sealed. It does coast much further and with less noise.

Has anyone else noticed this?


From the discussion it would appear that the lost of 2% of the pedaling energy in the wheel bearings doesn't appear to be noticeable to most people.

I most surely notice it so I assume that most of you ride well within your limits while a large part of my time I am at or near mine. And I am not a very fast rider anymore.
 




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