Ceramic balls for bearings?

i dunno. we always throw those units out when wear appears and replace
with new.

Jasper Janssen said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

they might be lighter. that said, I still wouldn't want them

\\paul

In article <[email hidden]>,
[email hidden] says...

Quoted message said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Harder, lighter, more precise, and ridiculously expensive overkill
for cycling applications.

--
[email hidden] is Joshua Putnam
<http://www.phred.org/~josh/>
Braze your own bicycle frames. See
<http://www.phred.org/~josh/build/build.html>

Jasper Janssen said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

More money than brains
EJ in NJ

On Fri, 28 Oct 2005 18:10:26 GMT, Jasper Janssen <[email hidden]>

Quoted message said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

The word of the day at the FSA booth was ceramic. FSA has been working
closely with the Danish firm, CeramicSpeed, to offer ceramic bearing
upgrades on a number of drivetrain components.

The ceramic bearings, made of silicon nitride, offer hugely reduced
friction, dramatically lighter weight, and reportedly, practically
infinite life spans as compared to even the best steel bearings.
Upgrade kits will be available for external bottom brackets (including
non-FSA branded ones), cartridge bearing hubsets, as well as
derailleur pulley wheels. According to the manufacturer, a full
accoutrement of ceramic bearings can save as much as a full second per
kilometer in a time trial.

Interestingly, the manufacturer is also quite sure that Tyler Hamilton
was the only rider to use ceramic bearings in the Olympic time trial.
How's he so sure? Well, there aren't exactly a bunch of people making
these things, and he still has the copy of the check from Tyler (yes,
he actually paid for these himself, and they're not cheap).

Skeptics of Tyler's innocence cite the whopping 19 second advantage he
held over second place in that race, but if these projected time
savings are accurate.... well, you do the math. I'm not taking sides
here, but it is rather interesting nonetheless, don't you think?
Complete external bottom brackets will run about $249USD and complete
hub upgrades will cost consumers about $300-400 for six cartridge
bearings. Sure, it sounds like a lot, but what's that podium spot
worth to you?

http://www.cyclingnews.com/tech/2005/shows/interbike05/?id=results/interbike0513

Jasper Janssen said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

Zipp makes an uberexpensive version of some of their wheels with ceramic
ball bearings.
You can distinguish them on some pro bikes because they have white
stickers instead of red.
Over the 35k km a pro rides during a year, you can probably save a
couple of Joules :-)

Quoted message said:

The ceramic bearings, made of silicon nitride, offer hugely reduced
friction,

But since bearing friction is lost in the noise of overall performance
anyway, this just won't matter.

Half of darn near nothing is still the same.

dramatically lighter weight

I sincerely doubt you'd save more than 50 grams replacing every
bearing on the bike by ceramics.

Quoted message said:

wheels. According to the manufacturer, a full accoutrement of ceramic
bearings can save as much as a full second per kilometer in a time
trial.

They have to promise something in order to sell these. But you can never
prove/disprove 1 sec/km gain, anyway, so they are probably safe.

--

David L. Johnson

__o | When you are up to your ass in alligators, it's hard to remember
_`\(,_ | that your initial objective was to drain the swamp. -- LBJ
(_)/ (_) |

David L. Johnson said:

Quoted message said:

wheels. According to the manufacturer, a full accoutrement of ceramic
bearings can save as much as a full second per kilometer in a time
trial.

They have to promise something in order to sell these. But you can never
prove/disprove 1 sec/km gain, anyway, so they are probably safe.

It's easily disproven, really, because it's so far beyond what could
even theoretically be possible. You'd need something like 20 watts of
more power to gain 1 s/km in a typical time trial situation.

The coefficient of friction for a ball bearing is somewhere between
0.001 and 0.002. If you do the math, with a 80 kg load even at high
speeds (40+ km/h) the power loss in the bearings would be less than one
watt.

-as

I would expect the 19 second advantage would be about 1/10 sec due to
the balls, and the balance due to the man.

The friction and weight advantage of these ceramic balls is so close to
zero that it is negligible. IMHO anyone who buys them (believing that he
will seriously improve performance) is being duped by the seller.

EJ in NJ

Quoted message said:

On Fri, 28 Oct 2005 18:10:26 GMT, Jasper Janssen <[email hidden]>

Quoted message said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

The word of the day at the FSA booth was ceramic. FSA has been working
closely with the Danish firm, CeramicSpeed, to offer ceramic bearing
upgrades on a number of drivetrain components.

The ceramic bearings, made of silicon nitride, offer hugely reduced
friction, dramatically lighter weight, and reportedly, practically
infinite life spans as compared to even the best steel bearings.
Upgrade kits will be available for external bottom brackets (including
non-FSA branded ones), cartridge bearing hubsets, as well as
derailleur pulley wheels. According to the manufacturer, a full
accoutrement of ceramic bearings can save as much as a full second per
kilometer in a time trial.

Interestingly, the manufacturer is also quite sure that Tyler Hamilton
was the only rider to use ceramic bearings in the Olympic time trial.
How's he so sure? Well, there aren't exactly a bunch of people making
these things, and he still has the copy of the check from Tyler (yes,
he actually paid for these himself, and they're not cheap).

Skeptics of Tyler's innocence cite the whopping 19 second advantage he
held over second place in that race, but if these projected time
savings are accurate.... well, you do the math. I'm not taking sides
here, but it is rather interesting nonetheless, don't you think?
Complete external bottom brackets will run about $249USD and complete
hub upgrades will cost consumers about $300-400 for six cartridge
bearings. Sure, it sounds like a lot, but what's that podium spot
worth to you?

http://www.cyclingnews.com/tech/2005/shows/interbike05/?id=results/interbike0513

Quoted message said:

According to the manufacturer, a full
accoutrement of ceramic bearings can save as much as a full second per
kilometer in a time trial.

According to my calculations, with a rider producing 400W and traveling
at 30mph, a 15W power savings is needed to drop 1 s/km. This is 3.75%
of the total power.

That is a lot of evergy to be sucked up by bearing friction... let
alone *saved* by using ceramics. I'd say the burden of proof is on
FSA...

But wait! For the same person producing only 10W and traveling at
6.5mph, a mere .065W savings would yield a 1 s/km improvement! Maybe
this is the realm they are thinking of?

Quoted message said:

Complete external bottom brackets will run about $249USD and complete
hub upgrades will cost consumers about $300-400 for six cartridge
bearings. Sure, it sounds like a lot, but what's that podium spot
worth to you?

Or... How much is marketing hype worth to you? Sure, if I was making a
million dollars a year to go fast on my bike...

Quoted message said:

On Fri, 28 Oct 2005 18:10:26 GMT, Jasper Janssen <[email hidden]>

Quoted message said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

The word of the day at the FSA booth was ceramic. FSA has been working
closely with the Danish firm, CeramicSpeed, to offer ceramic bearing
upgrades on a number of drivetrain components.

The ceramic bearings, made of silicon nitride, offer hugely reduced
friction, dramatically lighter weight, and reportedly, practically
infinite life spans as compared to even the best steel bearings.
Upgrade kits will be available for external bottom brackets (including
non-FSA branded ones), cartridge bearing hubsets, as well as
derailleur pulley wheels. According to the manufacturer, a full
accoutrement of ceramic bearings can save as much as a full second per
kilometer in a time trial.

Except the cones and cups are the things that wear\, not the ball
bearings. Unless they harder tha cones/cups, ceramic is an expensive
answer to a not asked question. Like a guy at shimano once told me when
I pointed to a shimano 'thing', asking, "what's that for?", "selling'
was his response.

Quoted message said:

Interestingly, the manufacturer is also quite sure that Tyler Hamilton
was the only rider to use ceramic bearings in the Olympic time trial.
How's he so sure? Well, there aren't exactly a bunch of people making
these things, and he still has the copy of the check from Tyler (yes,
he actually paid for these himself, and they're not cheap).

Skeptics of Tyler's innocence cite the whopping 19 second advantage he
held over second place in that race, but if these projected time
savings are accurate.... well, you do the math. I'm not taking sides
here, but it is rather interesting nonetheless, don't you think?
Complete external bottom brackets will run about $249USD and complete
hub upgrades will cost consumers about $300-400 for six cartridge
bearings. Sure, it sounds like a lot, but what's that podium spot
worth to you?

Too bad their bearing seals will still be sluggish, in spite of ceramiv
balls.

Quoted message said:

http://www.cyclingnews.com/tech/2005/shows/interbike05/?id=results/interbike0513

Qui si parla Campagnolo said:

Too bad their bearing seals will still be sluggish, in spite of ceramiv
balls.

Well, sluggish or ineffective. Ineffective can work for some people.

Jasper

Francesco Devittori said:

Jasper Janssen said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

Zipp makes an uberexpensive version of some of their wheels with ceramic
ball bearings.
You can distinguish them on some pro bikes because they have white
stickers instead of red.
Over the 35k km a pro rides during a year, you can probably save a
couple of Joules :-)

Ouestion #1; A typical Cat 2 rider, say 150 lbs, on a recient $2000
bike, riding at 25 mph alone, what % of his power is used to over come
wind & what % friction?
Just ballpark figures. I seem to remember <10%, maybe even <5%.
Question #2; If a rider at any speed, is riding into a 60 mph head
wind, why isn't he going backwards?
On a windy day, I once saw the Goodyear blimp flying backwards relative
to the ground.

Just curious, John

Francesco Devittori said:

Jasper Janssen said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Jasper

Zipp makes an uberexpensive version of some of their wheels with ceramic
ball bearings.
You can distinguish them on some pro bikes because they have white
stickers instead of red.
Over the 35k km a pro rides during a year, you can probably save a
couple of Joules :-)

Ouestion #1; A typical Cat 2 rider, say 150 lbs, on a recient $2000
bike, riding at 25 mph alone, what % of his power is used to over come
wind & what % friction?
Just ballpark figures. I seem to remember <10%, maybe even <5%.
Question #2; If a rider at any speed, is riding into a 60 mph head
wind, why isn't he going backwards?
On a windy day, I once saw the Goodyear blimp flying backwards relative
to the ground.

Just curious, John

john said:

Ouestion #1; A typical Cat 2 rider, say 150 lbs, on a recient $2000
bike, riding at 25 mph alone, what % of his power is used to over come
wind & what % friction?

On a smooth road and no wind, roughly 10% would be tire rolling
resistance and 90% would be aero resistance. Bearing friction is
generally so small that it isn't even considered.

Quoted message said:

Question #2; If a rider at any speed, is riding into a 60 mph head
wind, why isn't he going backwards?
On a windy day, I once saw the Goodyear blimp flying backwards relative
to the ground.

Are you riding in a hurricane? If you actually experienced a 60mph
headwind you'd have a tough time going forward... but at least we have
the ground to push off against... the blimp doesn't.

Ron Ruff said:

If you actually experienced a 60mph
headwind you'd have a tough time going forward... but at least we have
the ground to push off against... the blimp doesn't.

But it soon would...
--
Kenneth

If you email... Please remove the "SPAMLESS."

On Fri, 28 Oct 2005 18:10:26 GMT, Jasper Janssen <[email hidden]>

Quoted message said:

In another bike group someone appears to want to buy ceramic bearing
balls. WTF? Why on earth?

Boutique mentality. It's exotic and different, therefore it *must* be
Better. I have largely given up trying to actively discourage such
foolishness; I'll explain the issues as I understand them, and then
encourage the listener to spend *his* money verifying the data if
there's any question in his mind. If nothing else, I view this as an
investment in future entertainment.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

john said:

Question #2; If a rider at any speed, is riding into a 60 mph head
wind, why isn't he going backwards?

In the face of a 60mph headwind, if he's moving at all, he's doing
pretty well. It's not difficult to remain motionless in that
circumstance, but progress upwind would be very tiring and very slow,
involving the use of a very low gear. Bikes interact with the air and
the ground; even when the air is moving fast, the ground isn't. By
choosing a low enough gear ratio, forward progress is still possible.

Quoted message said:

On a windy day, I once saw the Goodyear blimp flying backwards relative
to the ground.

Yes. The blimp's interaction is solely with the air, not the ground.
If the air is moving at a speed greater than the blimp's highest
potential airspeed, then the blimp cannot make ground-relative headway
upwind.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

According to Werehatrack "It's not difficult to remain motionless in
that circumstance"

Just to pick a nit here, how would a bike be able to remain motionless?
Isn't forward motion necessary (ie wheels rotating) to raise the
necessary gyroscopic force to hold the bike upright?

EJ in NJ

Werehatrack said:

john said:

Question #2; If a rider at any speed, is riding into a 60 mph head
wind, why isn't he going backwards?

In the face of a 60mph headwind, if he's moving at all, he's doing
pretty well. It's not difficult to remain motionless in that
circumstance, but progress upwind would be very tiring and very slow,
involving the use of a very low gear. Bikes interact with the air and
the ground; even when the air is moving fast, the ground isn't. By
choosing a low enough gear ratio, forward progress is still possible.

Quoted message said:

On a windy day, I once saw the Goodyear blimp flying backwards relative
to the ground.

Yes. The blimp's interaction is solely with the air, not the ground.
If the air is moving at a speed greater than the blimp's highest
potential airspeed, then the blimp cannot make ground-relative headway
upwind.