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Old 05-11-11, 03:54 PM   #1
I_like_cereal
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Ceramic Bearings or Stick with steel

Should I consider replacing my steel bearings in my front and rear hubs with ceramic?

I will be repacking the hubs later this year as a yearly maintenance issue and am just curious if the increase in cost is paid for in performance gains.

I assume the performance increase will be very low maybe .5 to 1 watt and the weight decrease would be negligible.
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Old 05-11-11, 04:12 PM   #2
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Not worth it. Far more gains in position and technique, IMHO.
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Old 05-11-11, 04:42 PM   #3
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Ceramic bearings were developed for high temperature high rpm applications which would destroy grease and oil. Bicycles don`t operate in excess of 10,000rpm or at 100`s of degrees C.

High grade steel bearings are already available in tolerences that exceed the requirements of any bicycle by a factor of 10. But there is always the novelty value. Lots of people buy things they don`t really need.
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Old 05-11-11, 05:59 PM   #4
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But there is always the novelty value. Lots of people buy things they don`t really need.
That was pretty much my thought after reading some research on ceramic bearings. It appears that a rounder steel bearing would be a better investment.
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Old 05-11-11, 07:34 PM   #5
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Ceramic bearings were developed for high temperature high rpm applications which would destroy grease and oil. Bicycles don`t operate in excess of 10,000rpm or at 100`s of degrees C.

High grade steel bearings are already available in tolerences that exceed the requirements of any bicycle by a factor of 10. But there is always the novelty value. Lots of people buy things they don`t really need.
This is just wrong.

Go read some of zipps technical briefs. Even mentioning ceramic bearings without any grade is a waste of time. When people understand how a steel bearing can roll with less resistance than a ceramic bearing and vice versa then they should start typing.
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Old 05-11-11, 07:47 PM   #6
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This is just wrong.

Go read some of zipps technical briefs. Even mentioning ceramic bearings without any grade is a waste of time. When people understand how a steel bearing can roll with less resistance than a ceramic bearing and vice versa then they should start typing.
Lets go further than that. Even mentioning ANY bearing without mentioning any grade is a waste of time. However - for equivalent grades - the only advantage ( besides a slight weight reduction) a ceramic bearing has over any other is that they don`t need lubrication. However ceramic races are more prone to cracking than conventional races.

I think you`re entitled to your own opinion but before you decide that what I`m posting is `just wrong` suggest you read some other material besides just Zipp technical publications - preferably from a neutral reputable authority.
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Old 05-12-11, 08:19 AM   #7
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Zipp isn't exactly a non-biased source are they?

The power savings from ceramic bearing in good quality hubs are so small as to be almost undetectable, even assuming you replace Grade 25 steel balls with Grade 5 ceramic. The OP could get nearly the same benefit by just setting fire to a $20 bill.
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Old 05-12-11, 09:03 AM   #8
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I know there are several studies on the benefits of ceramic in the bottom bracket. Generally it saves 2-4 watts. The studies used various consitions like speed, grade, temperature.

This is from the pbk site:
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1.Apparently in our video demo above the Dura-Ace jockey wheel uses 0.78w to spin at 500rpm (I guess a typical rpm for a jockey wheel?) while a ceramic one requires just 0.06w. (CC)
2.Ceramic is very rigid, think almost of your Grandma’s old bone china, in a deformation test against steel bearings the ceramic deformed by 0.55 micrometres, a steel one by well over 0.70 (my eyes aren’t good enough to tell and the important part is the difference!).
3.According to Campagnolo if you use this sort of bearing in your wheels if you were rolling along nicely at 25mph you would save around 0.8 to 1 watt. Transfer this 1 watt to an 8% incline and it’s the equivalent of removing 340g from your bike!
So if you used ceramic all around, you might save maybe 5 watts. That's not insignificant. But it comes at a steep price.
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Old 05-12-11, 09:15 AM   #9
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The races are the part to go rough, first .. but that's part of the hub..
grade 25 balls are good enough ,

until you are a fast enough pro, then the people who make the ceramic bearings
will sponsor you with stuff, so they can claim it was their product
that made you fast, rather than your abilities, winning, making them look good.
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Old 05-12-11, 09:50 AM   #10
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So living in a wet environment and not having to lube the bearings would be a good thing?

Also I have regular races in the hub so replacing the steel bearings with ABEC5 ceramic and the jockywheels to ceramic would save some wattage. My jockey wheels are getting worn so maybe I can replace them.
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Old 05-12-11, 09:52 AM   #11
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Originally Posted by I_like_cereal View Post
Should I consider replacing my steel bearings in my front and rear hubs with ceramic?

I will be repacking the hubs later this year as a yearly maintenance issue and am just curious if the increase in cost is paid for in performance gains.

I assume the performance increase will be very low maybe .5 to 1 watt and the weight decrease would be negligible.
This may be the biggest hype fostered on bikers. They won't save you any measurable difference.
For our use good quality bronze bushings would be fine.
Ceramic bearings are designed for very high speed and heat like a turbocharger.
Bike wheels spin at 340rpm at 30mph.
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Old 05-12-11, 09:56 AM   #12
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Zipp isn't exactly a non-biased source are they?

The power savings from ceramic bearing in good quality hubs are so small as to be almost undetectable, even assuming you replace Grade 25 steel balls with Grade 5 ceramic. The OP could get nearly the same benefit by just setting fire to a $20 bill.
Amen brother. I think you are wrong about the benefit. It's more like burning a 50 or 100 dollar bill.
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Old 05-12-11, 08:10 PM   #13
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So living in a wet environment and not having to lube the bearings would be a good thing?

Also I have regular races in the hub so replacing the steel bearings with ABEC5 ceramic and the jockywheels to ceramic would save some wattage. My jockey wheels are getting worn so maybe I can replace them.
This might get a bit more complicated than you`re planning on. There are ceramic bearings and fully ceramic bearings. Fully ceranic bearings have ceramic races as well as ceramic balls. Anything short of that needs lubrication to prevent oxidation in a wet environment.

Then there is the suitability issue. Ceramic races are more prone to cracking than conventional metal races so unless you have hubs and a frame thats built to close tolerances and rigid enough to elininate all flex - your ceramic experience could be very short lived.

Ceramic bearings in jockey wheels are nothing new. Shimano introduced them some 25 years ago. I think you`ll find any gain from using them would be quickly negated by the drag of using a heavy chain lubricant. Some racers do funny things (funny to the average rider that is) like degreasing all bearings and chain and running a race using only a light oil as a lube. That works for the duration of some races and under those conditions it might be possible to measuse some small gain from doing so. To those riders the minor gain from ceramic bearings might be interesting. Personally I think that unless you completely clean and lube your complete drivetrain on a daily basis you`d not notice any difference with ceramics.

Last edited by Burton; 05-12-11 at 08:19 PM.
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Old 05-12-11, 10:43 PM   #14
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This might get a bit more complicated than you`re planning on. There are ceramic bearings and fully ceramic bearings. Fully ceranic bearings have ceramic races as well as ceramic balls. Anything short of that needs lubrication to prevent oxidation in a wet environment.

Then there is the suitability issue. Ceramic races are more prone to cracking than conventional metal races so unless you have hubs and a frame thats built to close tolerances and rigid enough to elininate all flex - your ceramic experience could be very short lived.

Ceramic bearings in jockey wheels are nothing new. Shimano introduced them some 25 years ago. I think you`ll find any gain from using them would be quickly negated by the drag of using a heavy chain lubricant. Some racers do funny things (funny to the average rider that is) like degreasing all bearings and chain and running a race using only a light oil as a lube. That works for the duration of some races and under those conditions it might be possible to measuse some small gain from doing so. To those riders the minor gain from ceramic bearings might be interesting. Personally I think that unless you completely clean and lube your complete drivetrain on a daily basis you`d not notice any difference with ceramics.
+1

As a Mechanical Design Engineer who has worked on bearing systems for high speed (10+K rpm) and incredibly stiff low speed intermittent motion systems; I strongly recommend AGAINST ceramic bearings for bicycle applications; unless you are a professionally supported racer.

Ceramic bearings are great - except you need a preload system that will compensate for the difference of thermal expansion over the operating temperature range to gain any benefit from them. A professional bike mechanic on hand all the time to adjust the bearings as the thermometer changes. If you don't have that kind of support; your ceramic bearings will only be better than 52100 steel at the very narrow temperature range they were tuned to; and that will only be for a few days.

The high speed spindles I worked on used 52100 (steel) bearings for several generations, then a generation of ceramic ball bearings (worst nightmare) and finally to hydrodynamic (self generating oil bearings) (not suitable for less than 3000 rpm).

The intermittent stuff used (and still uses) 440C (stainless steel) balls and raceways. It is not dissimilar to a headset application, except orders of magnitude smoother and stiffer. They are "sealed" ball bearings with plastic retainers and very low grease loading - all chasing smoothness. Full compliment bearings were tested - not smooth enough because of ball bumping (even class 1 balls have variance in diameter).

My bikes all use 52100 ball bearings; and boat trailer wheel bearing grease; wheels, BB, and headset.
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Old 05-13-11, 01:19 AM   #15
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nfmisso seems to know what he's talking about...
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Old 05-13-11, 10:55 AM   #16
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.. the jockywheels to ceramic would save some wattage. My jockey wheels are getting worn so maybe I can replace them.
Nope. Unlike hubs and BB, jockey wheels are all but unloaded. Even with a "perfect" bearing (i.e. zero power loss), the savings would be barely measurable much less noticeable.
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Old 09-23-12, 09:52 AM   #17
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Guys you can argue all you want about if they are a good buy or not but the facts speak for themselves. Check out the youtube comparison videos. Sure you can buy a precision steel ball that will run as well over short periods but it is 20 times heavier, rusts, requires maintenance.The ceramic ball kits are so cheap now it is worth it. You can pick up a kit for Shimano hubs for 23 bucks a wheel on ebay and it comes with grease and a spare ball in case you drop one.
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Old 09-23-12, 10:02 AM   #18
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Guys you can argue all you want about if they are a good buy or not but the facts speak for themselves. Check out the youtube comparison videos. Sure you can buy a precision steel ball that will run as well over short periods but it is 20 times heavier, rusts, requires maintenance.The ceramic ball kits are so cheap now it is worth it. You can pick up a kit for Shimano hubs for 23 bucks a wheel on ebay and it comes with grease and a spare ball in case you drop one.
First, you are over a year late to this party. Second, where do you get that nonesense that steel bearings are 20 time heavier? Steel bearings last for a short time? How about two years and 8000 miles and they were still in great shape and no rust of any kind.

Spend you money how you like but don't come up with fictional reasons to justify it.
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Old 09-23-12, 10:11 AM   #19
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Just because something is better doesn't mean it needs to be better for a particular installation. If something needs to be rated for 2,000 rpm for an extended period of time, spending more for something rated for 10,000 rpm won't make it any better. This happens ALL the time in marketing. Lets make something that can be proven better on a spec sheet and people will think it must be better then what they have been buying when in reality for their application it does nothing better then the old one.

Laundry detergent companies, tooth paste, oil, tires,...ect are always coming up with "new and improved". I laugh because essentially what they are tellin me is that what they use to sell me was junk!
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Old 09-23-12, 10:45 AM   #20
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First, you are over a year late to this party. Second, where do you get that nonesense that steel bearings are 20 time heavier? Steel bearings last for a short time? How about two years and 8000 miles and they were still in great shape and no rust of any kind.

Spend you money how you like but don't come up with fictional reasons to justify it.
x2, those kits will just replace the balls, your races and cones are still 20 times heavier and will rust anyways. Some people really like their kool-aid
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Old 09-23-12, 10:52 AM   #21
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First, you are over a year late to this party. Second, where do you get that nonesense that steel bearings are 20 time heavier? Steel bearings last for a short time? How about two years and 8000 miles and they were still in great shape and no rust of any kind.

Spend you money how you like but don't come up with fictional reasons to justify it.
Talking about fictional reasons to justify spending money, I think bicyclists are extremely good at that. See ultra-expensive crank-arms, for an example: "I spent $300 on these cranks, so they are stiffer than a $45 crankset! It must be, because I paid so much..."
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Old 09-23-12, 10:53 AM   #22
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So living in a wet environment and not having to lube the bearings would be a good thing?
Maybe so but ceramic bearings are not required to pull that off..

It is the contact seals on the cartridge bearing that do that ,
More-so ..
If the bearing is itself shielded from direct contamination..

also components like the Venerable SA 3 speed,
are able to flush out a lot of contamination as the oil for the internal gear leaks out Past the axle bearing.. and is replenished in the Core..
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Old 09-23-12, 06:10 PM   #23
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Talking about fictional reasons to justify spending money, I think bicyclists are extremely good at that. See ultra-expensive crank-arms, for an example: "I spent $300 on these cranks, so they are stiffer than a $45 crankset! It must be, because I paid so much..."
A $300 crank isn't expensive, it's mid-level. Priced a Campy Record Carbon or Dura Ace crank lately?
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Old 09-23-12, 06:18 PM   #24
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Talking about fictional reasons to justify spending money, I think bicyclists are extremely good at that. See ultra-expensive crank-arms, for an example: "I spent $300 on these cranks, so they are stiffer than a $45 crankset! It must be, because I paid so much..."
Put some real power into your crankset and maybe you too will be able to tell the difference.

You'd better believe I can FEEL the difference between an FSA crankset, a Shimano Ultegra 6700 crankset, and a Campy Record crankset.
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Old 09-23-12, 06:25 PM   #25
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Put some real power into your crankset and maybe you too will be able to tell the difference.

You'd better believe I can FEEL the difference between an FSA crankset, a Shimano Ultegra 6700 crankset, and a Campy Record crankset.
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