Ceramic

[Boeing]

I hear mixed opinions. In addition mixed claims. Some say ceramic last longer. Some say they dont. SOme say lighter some say not....All clain to help efficency

My brief self taught engineer days suggest that Ceramic was more for heat reduction in large friction than resistance...

In the words of Wall Street Are you 'buying or selling' the Ceramic Hype?

I got a BB and some pullies and the pedaling feels smooth but I am no faster yet. but not enough miles at fitness to tell anything. The cranks certainly free spin longer...

Hub Bearings? should I?

Headset? come on now....

 

[Martin318is]

Some also say that a simple search on the word "ceramic" will return more than 47 threaded results....

 

[BroDeal]

Ceramic bearings are one of the biggest scams in cycling, and that is saying a lot in sport that is full of scam products.

 

[Boeing]

Some also say that a simple search on the word "ceramic" will return more than 47 threaded results....

yea but a search for "legs" wont find You any

 

[Master50]

Campy, cone and cup steel bearings roll with less resistance than any ceramic cartridge bearing where there is s seal.
Shimano does have a rubber seal and are more resistant than Campy but still less resistant than say Mavic.
truth is the improvements are so small that it is almost all useless hype

 

[tubularglue]

correct me if I'm wrong,

Shimano has never used a sealed bearing on a wheelset.


steel ball bearings, and white shimanogreaze..........mmmmmmmmmmmmm


ceramic bearing........don't stand the test of time


eventually all balls drop on eachother..........as the wheel turnz

 

[Master50]

correct me if I'm wrong,

Shimano has never used a sealed bearing on a wheelset.


steel ball bearings, and white shimanogreaze..........mmmmmmmmmmmmm


ceramic bearing........don't stand the test of time


eventually all balls drop on eachother..........as the wheel turnz

Shimano has seals in many of their wheels, Just not cartridge bearings

 

[Black Dog]

Testing shows that when loaded good steal bearings roll as well as ceramics. Ceramic roll better by hand because they often have poor seals. It is a scam. A non solution to a non problem.

 

[Bustedknuckle]

I hear mixed opinions. In addition mixed claims. Some say ceramic last longer. Some say they dont. SOme say lighter some say not....All clain to help efficency

My brief self taught engineer days suggest that Ceramic was more for heat reduction in large friction than resistance...

In the words of Wall Street Are you 'buying or selling' the Ceramic Hype?

I got a BB and some pullies and the pedaling feels smooth but I am no faster yet. but not enough miles at fitness to tell anything. The cranks certainly free spin longer...

Hub Bearings? should I?

Headset? come on now....

Ceramics were developed for high pressure, high temps, hi speed...none of which are found in a bicycle.
Most ceramic bearings use standard steel cones and cups, not hardened and when contaminated, the hardness of the ceramic ball kills the steel parts quickly.

Save your money.

 

[Bustedknuckle]

Ceramic bearings are one of the biggest scams in cycling, and that is saying a lot in sport that is full of scam products.

Hear, hear.

 

[AnythingButKestrel]

The other prime issue I thought ceramics were a fix for was corrosion. Maaaybe they're a good deal if you ride in lots of water or live near the ocean. From what I've read from most honest wheelbuilders is that they simply won't make you go faster, and are usually inferior in rolling resistance to a quality steel bearing.

 

[Speedneedle]

Ceramics are not just ceramics... There an immensely big difference in the quality from cheap china ceramic bearings to eg. Ceramic Speed bearings. A few years ago I had a demonstration from the owner of Ceramic Speed, where he showed the quality differences from his bearings to cheap China ones.
The balls are much, much harder and he challenged us to try and break a small ball with a sledgehammer on a thick steel plate. We couldn't. Only things that got damaged was the hammer and steel plate, which got dimpled. The China balls shattered with a moderate blow from the hammer.

This translates to a much harder wearing bearing, as the Ceramic Speed bearing races has a very tough surface treatment as well. This also means that the seals does not have to be as tight and the amount and type of grease also can be tuned for less drag.

These bearings are expensive, but lasts a very long time. My BB bearings has now nearly 40.000km on them, with an grease repack twice a year. They still feel like new and spin very, very well.

I find this forum a bit old fasion and conservative sometimes. I know very well that the bike industry is filled with hot air products and hyperbole, but some new stuff is actually very good. Ceramic bearings CAN be an asset to a bike. You just need to look into what's good and what's crap, instead of making blanket statements. It's actually not that hard to stay informed these days.

PS. I don't say that Ceramic Speed is the only ones making good bearings, but I stick to them as I know what they are capable of. There's probably a few other companies out there making quality stuff. (not Boca and Ultimate. Thats cheap ****. Been there, done that...). Half of the Pro Tour teams are using their bearings, so there has to be something to it.

PPS. Full ceramic bearings are no good for most bicycle applications, as the ceramic races are very brittle and will not tolerate peak forces that is found in eg. wheels. Apparently it's not possible to manufacture the races to be as hard and strong as the balls.

 

[James Huang]

I'll agree that there's an awful lot of heady claims made in the industry and far too many people simply tossing the 'ceramic' word around. But lower friction is lower friction no matter how you slice it and in many cases, the losses aren't always negligible. We had a third-party lab test an FSA ceramic bottom bracket years ago (when they were still coming with bearings from CeramicSpeed) and the results surprised even us:

http://autobus.cyclingnews.com/tech/?id=2006/reviews/FSA_MegaExo

That same lab also tested a bunch of other bottom brackets (both old and new) and the recurring theme was that most modern ones were pretty bad in terms of bearing friction.

That being said, ceramic bearings are like any other bearing: there are widely varying levels of quality, grease type, grease fill percentage, and seals and it all affects friction. All ceramic bearings are definitely not created equal and while the crappy ones are just that, the really good ones can be shockingly good. In some ways, it's akin to the frame material debate where someone invariably says something like 'carbon is always better than aluminum'. Part of the reason why Mavic wheels seem to spin so well, for example, is that the bearings use non-contact metal shields on their inner sides (the ones not facing the outside world).

Yes, so-called ceramic bearings in the bicycle industry are almost always hybrid ceramics with steel races (and I do my best to make sure to make that distinction wherever possible) and in general, don't offer as much of an advantage as full ceramics of similar quality (which are far more expensive).

But none of you can spin the drivetrain of a Pro Tour bike that's been fully treated (and yes, some of them still have full seals) and say that there's no perceptible difference.

Does it matter to general consumers? Probably not. But to generalize and say that all ceramic bearings are nothing but marketing BS with no benefit to cycling isn't exactly accurate, either.

 

[Boeing]

PErhaps mods are better suited modifying search engins than policing personalities

Top Results for ceramic - Pre Discoboy's meat grind modflame (no pun intended with result toward bottom titled "plea for Integrity in cycling journalism 2010") pure thread topic results.

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Ceramic Headsets



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Cycling Etiquette

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You might be a poser...




checkout LA's size...

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The Other Kind of Doping


evans, Basso, doping, who's not doping thread!


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A Plea For Integrity In Cycling Journalism in 2010

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Battle of the frame materials.


Bb30


Di Lucca back racing


My Bikes

 

[BroDeal]

Testing shows that when loaded good steal bearings roll as well as ceramics. Ceramic roll better by hand because they often have poor seals. It is a scam. A non solution to a non problem.

To expand on this, I'll quote a post from EpicriderGMAC on weightweenies:

In the low temperature, low speed applications that bicycles face, there is no benefit to ceramic bearings over steel bearings in an apples to apples comparison.

Here's why:

A hub or bottom bracket bearing faces axial loads while the cyclist applies power to the bike. Axial loads must be distributed by the balls of the bearing on the bearing race.

A misaligned bearing, even by the smallest of margins (outside +/- 0.0005''), will cause substantial increases in rolling friction.

Ceramic balls on steel races, commonly marketed as Hybrid Ceramic bearings (such as Enduro and Boca bearings), are not good unless perfectly sized. This is because ceramic balls are much harder than the steel races. If the balls are not perfectly toleranced (as they rarely are for hybrid ceramics) to the race outer diameter, once axial loads are applied to the bearing during bicycle riding the race will be damaged. Once the race is damaged due to the hardness of the ceramic balls, friction increases and the bearings will deteriorate quickly.

Alright, so you purchase a set of perfectly toleranced, high precision full ceramic bearings from Ceramic Speed for your Mavic wheels. You install them noticing that they are so light and spin so smooth in the bike stand.

Why are the bearings so light? Why do they spin so smooth in the stand? The dirty secret about ceramic bearings in the bicycle industry is that the key ingidient is less grease and fewer seals.

That's it. Zipp uses 85% fill for steel bearings and 50% fill for ceramics.

FSA reduces the number of seals in their ceramic bottom brackets from 4 down to 2, as well as fills their ceramic BB's with lower viscosity grease. They feel great in the stand!

The truth is that ceramic bearings DO NOT work for long without proper grease! The balls still need to be protected from the race, just like in every steel bearing. You can get away with it for a while (or even just use oil as fill), but the bearing will deteriorate quickly and increase in friction yet again.

Even if everything is perfect, comparing good bearings to good ceramic bearings, we are talking a MAX net power gain in IDEAL conditions to be 0.5-1 watt.

So--you want fast bearings? Get a good set of steel bearings, lube them up well with low viscosity grease, and take out the seals. Check up on them every couple of weeks to regrease.

Mission accomplished.

http://weightweenies.starbike.com/f...sid=7bd644c97b1d947ab23d5e8c6731dcf9&start=30

And that pretty much sums it up.

And that incredible--make that unbelievable--4% figure in the CN article above has been roundly criticized on more knowledgeable forums. 4%!! Give me a freakin' break. Just what percentage did the drivetrain and hubs supposedly consume in this test? They must have used Superglue instead of grease for the steel bearings.

 

[James Huang]

BroDeal:

That test was run on a dedicated test rig looking *only* at the bottom brackets - no other drivetrain components were used aside from a reference chain that was shared between all tests.

I'm fine with criticism on "more knowledgeable forums." But what would be much more interesting is a link to another study where someone has actually measured the differences instead of just tossing out conjecture.

 

[Bustedknuckle]

I hear mixed opinions. In addition mixed claims. Some say ceramic last longer. Some say they dont. SOme say lighter some say not....All clain to help efficency

My brief self taught engineer days suggest that Ceramic was more for heat reduction in large friction than resistance...

In the words of Wall Street Are you 'buying or selling' the Ceramic Hype?

I got a BB and some pullies and the pedaling feels smooth but I am no faster yet. but not enough miles at fitness to tell anything. The cranks certainly free spin longer...

Hub Bearings? should I?

Headset? come on now....

Gadget among a long list of gadgets in a flat bicycle market. There are many better places to spend your $. BTW-pro teams get these for free, replace or service these regularly in a 3 week race, have a legion of mechanics and a warehouse full of spares. For the 'mere mortals' of us out there, again, save your $. Along with things like oversized fork steerer lowers, seatmasts, oversized handlebars, internal cable routing and my favorite, BB30('creaky' 30).

 

[BroDeal]

I have a finely tuned bullsh!t detector, but in this case the figures are so outrageous that it does have to be that finely tuned. If someone had never read anything about bicycle drivetrain efficiency, he could still do a simple thought experiment to show that 4% of 100W loss in the BB is unbelievable. Most drivetrain losses obviously occur in the chain, so start adding numbers. 4% for the BB, several times that for the chain, and a little more for the jockey wheels, and figure of 20% is quickly reached. At that point it is not hard to ask yourself if it sounds remotely possible that around 20% of power at 100W would be consumed by the drivetrain. That is the point when the light bulb should go on, indicating that something is very wrong.

Wilson's Bicycling Science gives a figures for drivetrain losses of less than 4% at 100W. The BB losses are a small fraction of that. In fact testing by SKF and pulbished in Cykel Magasinet showed that at 100 RPM and 400W, a Record BB used only 0.6W. The same BB with ceramic bearings used 0.02W, so if you happen to be able to sustain 400W--I am sure I'll have no problem doing that --then you could save a whopping 0.58W. Divide 0.58 by 400 and you get:

Yes, folks it's true. You too can buy this wonderful, new fangled doohickey of the space age and save a collosal amazing 0.145%. Not 14.5%. Not 1.45%. But 0.145%. I know it is hard to believe, but it is fantastic and true. Order now and we'll send you not one, but two--two!!--for a special price only available on TV. Call within the next twenty minutes. Special offer not available in California and New York. You must be at least eighteen to order.

This of course disregards the fact that in bicycles applications the seal drag overwhelms bearing losses by a considerable margin...

 

[Night Rider]

I remember reading an article by some physicist (from memory name was Ben from a company in UK) that absolutely blew that 4% figure (theory) to pieces. He wrote all the scientific formulas down for each of steel bearings, ceramic, seal drag, etc and concluded that even if ceramic bearings were up to fifty percent more efficient than steel (pie in the sky theory) that the gain in watts would be about three quarters of one watt at the crank.

Basically the independent science proved that in reality the seals were causing more drag, the ceramic balls had marginally less resistance (like one or two percent) and therefore you had no gain. I think one of the quotes from another scientist commenting on the article was that you would get more benefit drafting behind a wasp! Lol

(I will try and search for the article at lunchtime)

So, for those of you with an obscene amount of money to spend, and ridiculously low talent ... go ahead and buy ceramic bearings. You would get has much benefit burning your $50 notes.

 

[bobs nob]

It's times like these I am relieved to know I don't have the money for any such extravagance. I don't even have the money for something that might be a meaningful and instant improvement such as a better saddle or wider bars. But it's interesting to read about the hype.

~ The only difference between men and boys is the cost of their toys~

 

[Boeing]

Higher Modulus of Elasticity

less Weight

less Conductivity

less Thermal Expansion