Bicycle Mechanics - 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.

Not worth it. Far more gains in position and technique, IMHO.

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.

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.

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.

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.

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.

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:

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.

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.

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.

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.

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. :50:

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.

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.

nfmisso seems to know what he's talking about...

.. 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.

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.

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.

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!

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

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..."

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..

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? :)

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.

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.

http://media.tumblr.com/tumblr_m0d2c07iRw1qcqm5r.jpg

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.

Fabian Cancellara is happy with FSA Gossamers, and you could be too. :thumb:

Good artical on bearings
http://www.active.com/cycling/Articles/Bearing_It_All__Ceramic_Bearings.htm (http://www.active.com/cycling/Articles/Bearing_It_All__Ceramic_Bearings.htm)

if you want ceramic to you need to go with a full ceramic other wise hust get good old steel but not cheap.

Good artical on bearings
http://www.active.com/cycling/Articles/Bearing_It_All__Ceramic_Bearings.htm (http://www.active.com/cycling/Articles/Bearing_It_All__Ceramic_Bearings.htm)

if you want ceramic to you need to go with a full ceramic other wise hust get good old steel but not cheap.

That article is crap simply because it doesn't quantify the advantages in real world terms. Ask Mr. Zinn what the actual savings are and compare that to the whole. Hint: you'll be hard pressed to actually measure it. And no, spinning wheels and cranks with absolutely no load is not a valid demonstration (unless you ride your bike that way).

That article is crap simply because it doesn't quantify the advantages in real world terms. Ask Mr. Zinn what the actual savings are and compare that to the whole. Hint: you'll be hard pressed to actually measure it. And no, spinning wheels and cranks with absolutely no load is not a valid demonstration (unless you ride your bike that way).

You would need to take up that issue with the person who wrote the artical By Lennard Zinn • VeloNews (http://www.velonews.com/)

+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.

I disagree your over mechanical explanation negates the consideration of molecular wear due to the attraction between two rotating pieces of steel. Also everyone knows that stainless has very good toughness properties but is not exceptionally hard.
Most people are not riding bikes that need their bearings fine tuned but are concerned about the edge the weight reduction makes, and the decrease in friction from a high grade polished surface which has a tendency not to wear as compared to its steel counterpart. Also your expansion tables are wacky, ceramics does not expand and contract in different temperatures the way steel does and therefore does not require fine tuning relatively due to expansion.
Either you are trying to impress us with engineering prowess or you are working for a steel bearing manufacturer.
please replay:- Ray Evans (Rolls Royce jet engine machine build engineer)

PS Have you ever riding a bike with ceramic wheels I go through the swedish winters every year with them and they are fabulous. you dont have to worry about the harsh weather taking out your lube and they stay in shape regardless of the beating they take.
Besides everyone in this forum keeps barking about the cost and you can pick up a set for 23bucks a wheel on ebay including lithium soap. I know none of us are that broke hahaha

Amen brother. I think you are wrong about the benefit. It's more like burning a 50 or 100 dollar bill. :50:

Nah, they all weigh the same. Oh, you meant benefit on one's bank account?;)

OP get the ceramic (if you can afford them) and decide for yourself. If I had a lot of money, I wouldn't mind giving it a try, for fun.
Stainless steel vs ceramic, this is how it was explained to me. "When using stainless steel bearing, under high RPM and/or load (friction). Stainless still will create electro static energy, causing the steel bearings to break down on the molecular level. Ceramic bearings do not have this characteristic, however, more expensive and more brittle"

I disagree your over mechanical explanation negates the consideration of molecular wear due to the attraction between two rotating pieces of steel. Also everyone knows that stainless has very good toughness properties but is not exceptionally hard.
Most people are not riding bikes that need their bearings fine tuned but are concerned about the edge the weight reduction makes, and the decrease in friction from a high grade polished surface which has a tendency not to wear as compared to its steel counterpart. Also your expansion tables are wacky, ceramics does not expand and contract in different temperatures the way steel does and therefore does not require fine tuning relatively due to expansion.
Either you are trying to impress us with engineering prowess or you are working for a steel bearing manufacturer.
please replay:- Ray Evans (Rolls Royce jet engine machine build engineer)

PS Have you ever riding a bike with ceramic wheels I go through the swedish winters every year with them and they are fabulous. you dont have to worry about the harsh weather taking out your lube and they stay in shape regardless of the beating they take.
Besides everyone in this forum keeps barking about the cost and you can pick up a set for 23bucks a wheel on ebay including lithium soap. I know none of us are that broke hahaha

Gee Ray, after spending sone 35 years in the aerospace industry myself, I usually like to exchange ideas and info with other people from that field - but I'd prefer to do it with people who are at least objective.
your previous post read:

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.

I guess this is the site you're referring to:

http://item.mobileweb.ebay.ca/viewitem;PdsSession=fcba55271390a47a063733d7ffe29e33?itemId=140841988668&cmd=VIDESC

But wait a minute ...... thats YOUR site Ray .... complete with a link to your webpage ... http://www.raysbicycle.se/

I really hate it when people use themselves as a reference.

Guess you're not really that good of an engineer - otherwise you wouldn't have to stoop to selling cheap junk on eBay. Yeah - I looked myself and consider it cheap junk relative to what can be bought for the same money from reputable bearing manufacturers : ie a fully assembled 440 stainless radial bearing with grade 5 ceramic balls for typically $9. Thats actually less then what you're charging for loose balls. Full ceramic radial bearings marketed for bicycle wheels , on the other hand, typically cost $99 EACH.

And lets put some facts on the table:
(1) I don't know of ANY ceramic bearing manufacturer that claims that ceramic bearings are 1/20 the weight of steel and you don't even do that on your own site. Most claim a potential weight reduction of up to 60%. But thats only for FULL ceramic bearings.
(2) Ceramics are, in layman's terms, a kind of glass. Glass is hard, and brittle, and doesn't take shocks well. Oh look at that! You're at least aware of that and on your site specified "only recommended for road bikes and commuters." Full ceramic radial bearings are even more fragile, and ceramics do have a different coefficient of expansion than metals, and that combination is what was referred to in the previous post.
(3) The claim that 'ceramics are rounder' is a joke. Ceramics CAN be rounder, but ... grade 5 is grade 5, regardless of the material.
(4) The turbine in a jet engine might spin at 10,000rpm and some microturbines might spin at 500,000rpm, but a bicycle wheel at 30mph is doing less than 500rpm.

I'm all for practical engineering myself. The motor in an F1 race car typically costs several million dollars abd has a life expectancy of less than five hours. I don't want that kind of engineering in my bicycle.

This argument is kinda like comparing a stainless steel spoon and a sterling silver spoon. They both work equally well. One just cost more and has snob appeal.

This argument is kinda like comparing a stainless steel spoon and a sterling silver spoon. They both work equally well. One just cost more and has snob appeal.

This argument is kinda like comparing a stainless steel spoon and a sterling silver spoon. They both work equally well. One just cost more and has snob appeal.

At least with the silver spoon, your friends can see it's silver. With ceramic bearings or lightweight cassettes, no one will notice, so you have to tell them in order to show off.

A quick guide about cartridge bearings-

Bearings come in different types. Most bicycle bearings are roller-ball, with some parts using needle bearings. You normally can't switch the type of bearing since there is not an alternate type of the same dimensions--so don't expect to convert a ball-bearing wheel to needle bearings.

Next there's different material types. From cheapest to most-expensive, they run like this-
1--chrome steel
2--stainless steel
3--hybrid (ceramic balls with stainless races)
4--full-ceramic (ceramic balls and ceramic races)
......Among the ceramic components there are also two different types: Zirconia/ZrO2 (white) and Silicon Nitride/Si3N4 (black). I don't know which of the two is better, but the black ones normally cost more. You can find examples of bearings that have balls of one type and races of the other, but usually they use the same material for both parts of the same bearing.

There is also brands of bearings. To an extent the brand signifies a higher quality, but also a significantly higher price. NSK, F4G (-that '4' is really an "A", but board censors that word,,,), Timken and Natchi are a few brands. Look around on eBay. They may not have retail packaging, but be sure you are buying NEW bearings. A lot of pulls/used parts are on eBay too.

Bearings can be open, or have seals or shields on one or both sides. Bicycle cartridge bearings are almost always double-shielded or double-sealed, and either will work just the same. A seal is a rubber washer and a shield is a metal ring with a rubber washer under it. The shields and seals keep grease in and dirt out.

There are also various systems of rating precision of bearings. The most-common one is the ABEC scale, but it is only applied to metal bearings. It is an odd number, 1 through 9. Typical-quality metal bearings will be rated a 5 or 7. You can look for steel ABEC-9's but you probably won't find them since they are expensive to grind and don't hold the tolerances long anyway. Nowadays if they want a bearing that accurate, they use ceramics instead.

Ceramic bearings can be ground far more accurate than steel can, and so ceramic bearings usually do not give any ABEC rating. http://en.wikipedia.org/wiki/ABEC_scale

Your bicycle's bearings are not anything special. Bearings are rated by their typical inner/outer/width dimensions, and there's about five thousand "standard" sizes less than ~2 inches diameter. Having custom bearings made costs a fortune and there's no reason--maybe NASA did it for the Mars Rover, but no bicycle company does it. The bicycle part manufacturer may specify a certain 'custom' bearing, but it almost certainly is a standard size that can be replaced. Their 'custom spec' is often nothing more than a particular color of plastic for the seals.

----------

So then, shopping for bearings:

The bearings usually have a number stamped on them. Usually it is a four-digit number, possibly followed by two or three additional letters/numbers. (example: 6902-2RS ) Bearing sites online will give you cross-references; usually you only need to find a double-sealed bearing that has the same first four numbers.

Prices: carbon steel and stainless-steel usually cost about the same.
Hybrids cost about double what carbon or stainless bearings do, but still much less than full-ceramics.
Full-ceramics are the most expensive.

One common wheel cartridge bearing size is a 6902. Here is some real examples of prices for the different materials:

A carbon steel 6902 for $6 ------------------------- http://www.vxb.com/page/bearings/PROD/6902ZZ-1
A stainless steel 6902 for $7 ----------------------- http://www.vxb.com/page/bearings/PROD/Kit7446_1
A hybrid 6902 for $18 ------------------------------ http://www.treefortbikes.com/product/333222341828/349/ABI-Ceramic-Hybrid-6902.html?gclid=CNiBhObw0LICFQsGnQodH3sAFA
A Zirconia (white) full-ceramic 6902 for $70 --------- http://www.vxb.com/page/bearings/PROD/Kit8795
A Silicon Nitride (black) full-ceramic 6902 for $109 -- http://www.vxb.com/page/bearings/PROD/Kit7728

For a bicycle, hybrid bearings offer most of the advantages of full-ceramics, at a much lower cost. One company named ABI markets a line of hybrid-ceramic bearings in common bicycle sizes. Search Google for "ABI hybrid bicycle bearing" to find bicycle-parts retailers carrying them.

If you can afford full-ceramics, hey, have fun. I wish I could.
Often people note that they feel different (harder) and that metal bearings always feel "mushy" afterward.
The full-ceramics do have a small bit less friction, but most technical references only note their advantages for very-high-RPM uses (above 25K RPMs) in low-lube instances (where the bearings are only oiled and not greased). Also they don't take shock-loading well, and a lot of heavy equipment specifies metal-bearings only. Ceramics only come in ball-bearings (that I've seen), all other types (needle, conical roller, radial) are still all metal.

For the lowest possible friction, it is also possible to buy pure teflon powder and add that to the grease in the bearings. Spurlock tools (online) sells it fairly cheap. http://www.spurlocktools.com/id39.htm
Carbon steel bearings still need at least some oil for corrosion resistance but stainless and ceramic bearings don't. With stainless and ceramics, you can remove all the grease and replace it with teflon powder.

I posted this last year in another ceramic bearings thread:

I just spun my front wheel while the bike was on the repair stand. It's a 1550 gram aluminum wheel set, White Industries hubs, Kinlin 30mm rims, and GP4000 tires. I have between 3,000 and 4,000 miles on it so far, with the original factory bearings. I gave it a decent pull, but didn't try to maximize the wheel speed.

Timing the front wheel spin down:
6 min 55 secs: finishing spinning in circles, starting the final oscillation back and forth, due to the weight of the rim joint.
11 min 20 secs: finally stopped completely.

Yes, it was moving for over 11 minutes with good old steel bearings. And some of this drag on the wheel was due to air friction when it was spinning fast. How much less drag could there be?


~~~~~~~~~~~~~~~~~~~~~~~
I've seen quite a few comments on BF about early failures of ceramic bearings. And I was on a ride a few years ago, when another rider's bottom bracket locked up completely--he couldn't turn the crank at all. His ceramic bearings were about a week old. Maybe they were installed incorrectly.

Another issue that complicates comparisons is that new bearings are always 'sticky', because the shields or seals are tight. Because of this, any used bearing will probably turn a lot easier than a brand-new one will. Take the seals out (temporarily) if you want to do quick direct comparisons.

What I'd like to see is LESS maintenaince when I spend more money. FSA is one of several companies that market hybrid bearings (ceramic balls in stainless or carbon steel races). Here's how they describe their bearings:

FSA recommends inspecting the hybrid ceramic bearings:

• After each riding season or after 8,000-10,000 KM, whichever comes first
• After use in rain, mud or wet conditions
• After drive train has been cleaned with solvents or sprayed by high pressure water jets
• Anytime rotational smoothness, evidence of corrosion, or seal damage is apparent.

And should I mention that in their opinion 'inspection' involves the removal of the bearing assembly - which on most cases are a press fit requiring bearing extractors and bearing press for removal / installation?

Sorry but I'm not feeling any irresistible compulsion to make a switch. I clean my drivetrain every month and ride in rain every week. And I don't pull my current bearings everytime I do that.

I think the hype over ceramic bearings is frictional.
:D

I guess this is the site you're referring to:

http://item.mobileweb.ebay.ca/viewitem;PdsSession=fcba55271390a47a063733d7ffe29e33?itemId=140841988668&cmd=VIDESC

But wait a minute ...... thats YOUR site Ray .... complete with a link to your webpage ... http://www.raysbicycle.se/

I really hate it when people use themselves as a reference.


Yep, that was my suspicion. Thanks for pointing it out. Newbie is both a spammer and a shill.

I guess I better throw away my Fulcrum Racing Zero Comp Ltd. Ed. wheelset with CULT bearings AND my Campy Eurus with USB bearings. And while I am it I should remove all Campy Record equipment from my bikesand replace it with SORA or whatever.

According to some here I will never, ever notice any difference.

Not! :roflmao2:

I think the hype over ceramic bearings is frictional.
:D

Good one! :D

I guess I better throw away my Fulcrum Racing Zero Comp Ltd. Ed. wheelset with CULT bearings AND my Campy Eurus with USB bearings. And while I am it I should remove all Campy Record equipment from my bikesand replace it with SORA or whatever.

According to some here I will never, ever notice any difference.

Not! :roflmao2:

If the stuff works - why throw away perfectly good equipment? THAT was really the point of this discussion as I saw it. ;)

I guess I better throw away my Fulcrum Racing Zero Comp Ltd. Ed. wheelset with CULT bearings AND my Campy Eurus with USB bearings. And while I am it I should remove all Campy Record equipment from my bikesand replace it with SORA or whatever.

According to some here I will never, ever notice any difference.

Not! :roflmao2:

Yeah, all that bling makes you go so fast!
Seriously, your attitude embodies the worst that there is in cycling: ignorance and consumerism.

There are people like you in the Hi-Fi enthusiast world. The ones who go for these cables. (http://www.amazon.com/Monster-M2-4s-Master-Speaker-15/dp/B000CC1Q5O/ref=sr_1_2?s=electronics&ie=UTF8&qid=1348613237&sr=1-2)

... FSA recommends inspecting the hybrid ceramic bearings:

• After each riding season or after 8,000-10,000 KM, whichever comes first
• After use in rain, mud or wet conditions
• After drive train has been cleaned with solvents or sprayed by high pressure water jets
• Anytime rotational smoothness, evidence of corrosion, or seal damage is apparent.

And should I mention that in their opinion 'inspection' involves the removal of the bearing assembly - which on most cases are a press fit requiring bearing extractors and bearing press for removal / installation? ...
That maintenance advice is a bit,,,,,, overbearing. ;)

I have not known ceramics to require any more maintenance than steel bearings would in the same instance.... And checking all those times isn't a bad idea for steel bearings either.
The main weakness that ceramics have is shock loading, and full-ceramics have that problem a lot more than hybrids do.

Full-ceramic bearings are ideal for spinning very light loads at very-high RPMs, things like dental drills. You can use them in bicycle parts, but you're paying a lot of money for what will be a very small practical gain.

I posted this last year in another ceramic bearings thread:

I just spun my front wheel while the bike was on the repair stand. It's a 1550 gram aluminum wheel set, White Industries hubs, Kinlin 30mm rims, and GP4000 tires. I have between 3,000 and 4,000 miles on it so far, with the original factory bearings. I gave it a decent pull, but didn't try to maximize the wheel speed.

Timing the front wheel spin down:
6 min 55 secs: finishing spinning in circles, starting the final oscillation back and forth, due to the weight of the rim joint.
11 min 20 secs: finally stopped completely.

Yes, it was moving for over 11 minutes with good old steel bearings. And some of this drag on the wheel was due to air friction when it was spinning fast. How much less drag could there be?

The day that you ride your bike with the wheels spinning in the air unloaded will be the day I take your experimental results seriously. This is an apple-to-oranges comparison with no bearing on real life usage parameters (pun fully intended).

OK, so lets go for yet another opinion:


Discussing ceramic bearings recently with industry guru Paul Lew (http://roadcyclinguk.com/blogs/richards-blog/paul-lew-and-the-reynolds-rzr-92-wheelset.html), I was told that he considers them unsuitable for cycle duty, since they are better at sustaining very high rotational speeds with low loadings that the reverse, typical in cycling, where high loadings are applied at low rotational velocities.

Source: http://roadcyclinguk.com/news/ck-ceramics-hollowtech-ii-bottom-bracket-review.html

Paul Lew is the designer of the Shimano Dura-Ace 7800 wheel-set, a consultant to Reynolds Cycling and to the US Military.

The day that you ride your bike with the wheels spinning in the air unloaded will be the day I take your experimental results seriously. This is an apple-to-oranges comparison with no bearing on real life usage parameters (pun fully intended).
Nonesense, it's a suitable demonstration of the inherent friction in the bearings and that relative drag isn't load dependent.