Ceramic?

Discuss light weight issues concerning road bikes & parts.
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phourgenres
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by phourgenres

What's everyones opinion on ceramic BBs and hubs. Besides the fact they are lighter, do you find them to cause less friction like they advertise, or are they just a fad?

Phill P
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by Phill P

:search:

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sugarkane
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by sugarkane

I always thought it was a fad.. Until I got a set of SR cranks with the campag cult BB
And a set of extralite/evne 45s with the ceramic upgrade..
I'm totally sold now, I wouldn't want a set of wheels or cranks with out em.
It's not a weight thing either they are just so much smoother

Simon BP
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by Simon BP

The weight saving with ceramic bearings is very slim! Only a few grams on a complete set of bearings tops! It's the significantly lower friction that is the benifit. It saves energy, making you go faster. It is however an expensive upgrade, and one that can not be seen visually on the bike like for instance a new wheelset can - so many people choose to spend the money on other more visual parts instead.

phourgenres
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by phourgenres

Phill P wrote::search:


I tried searching this function. I got directed to number of threads about ceramic brakes, and threads about wheels using ceramic, but couldn't find one directly comparing ceramic. If you know of one, can you please direct me to it.

Ghost234
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by Ghost234

For the most part you won't notice much as a result of a ceramic upgrade. They wear away much quicker than steel, and need to be serviced quite regularly.

Expensive upgrade, very marginal returns. But many people like the upgrade.

Simon BP
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by Simon BP

Nope, propper ceramic bearings outlast regular steel ones by far if serviced corectly.

artray
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by artray

Depends on the size and how many ,,,if there small you are not going to notice much difference ,,for most part they seem like a nice selling point ie "and these hubs also have ceramic bearings" like its going to make you ride up alp de huez 10 mins quicker,,,i do have ceramic bb and ceramic jokey wheels but i like many am ceramic fool ,,,,
artray

FredBloggs
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Joined: Wed Jan 28, 2009 11:33 pm

by FredBloggs

Whilst looking for some Ceramic bearings a while back I came across this informative thread which may well be worth taking a look at, specifically Post #31

http://forums.roadbikereview.com/compon ... 754-2.html

HTH

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Zen Cyclery
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by Zen Cyclery

I really don't see the practicality in ceramic bearings.

From my understanding (and engineers please correct me if I'm wrong), ceramic bearings were originally intended for machines that have extremely high rpms. Such things like airplanes that operate in an rpm range a bicycle would never reach. In this range, apparently they do dissipate heat a bit more efficiently.
However, for a bicycle, they make no difference at all. From what I have heard, they have a shorter wear life, and all they really accomplish for us cyclists is the almighty "bling" factor.
So in conclusion, don't waste your money. Putting that towards a different upgrade would more than likely be much more beneficial.
Last edited by Zen Cyclery on Mon Dec 05, 2011 6:39 pm, edited 1 time in total.

Simon BP
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by Simon BP

I can not disagree more.
Have you tried to hold two identical BB's in your hand, where one was with ceramic and the other with standard bearings, and then felt the difference in resistence? It may only be a little, but that is still less friction which means that less energy is wasted, making you go faster for the same amount of energy. It's simple physics..

and btw, propper ceramic bearings are alot stronger than steel, and last longer. At work we have a large metal-clamp(or whatever they are called in english) with a nice small ball-shaped dent in it. That came from a used ceramic bearing that one of the mechanics wanted to test the strength of. So he slammed et very hard with a hammer, and all there happened was the dent in the metal - the bearing did not break.

andyindo
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by andyindo

Marginal gains, VERY marginal gains. If you can afford it then why not. I wouldn't loose sleep over it and I very much doubt my lack of ceramic bearings would cause me to lose a race. But if I could justify it I'd buy some :thumbup:

eric
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by eric

The ceramic bearings marketed to the bike industry aren't very good. They are only hybrid ceramic, not full (too expensive for us). They're the same grade as good steel bearings. To make them seem to be smoother, they're made with lower drag seals. But those seals don't seal as well, so the bearings get contaminated more easily. This leads to a shorter life.

I bought the ceramic hype until I figured this out. Now I use good steel bearings, which work as well and last longer.

JensW
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by JensW

Simon BP wrote:I can not disagree more.
Have you tried to hold two identical BB's in your hand, where one was with ceramic and the other with standard bearings, and then felt the difference in resistence? It may only be a little, but that is still less friction which means that less energy is wasted, making you go faster for the same amount of energy. It's simple physics..

and btw, propper ceramic bearings are alot stronger than steel, and last longer. At work we have a large metal-clamp(or whatever they are called in english) with a nice small ball-shaped dent in it. That came from a used ceramic bearing that one of the mechanics wanted to test the strength of. So he slammed et very hard with a hammer, and all there happened was the dent in the metal - the bearing did not break.


but that doesn´t have to say to much, if the grease and the seals isn´t the same sort in both, the comparison isn´t fair.

Camilo
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by Camilo

For those that feel that ceramic bearings are "smoother" or "more efficient", I wonder how much smoother and more efficient? I mean, the huge forces we're overcoming are air and gravity. Yes, I know that friction in the spinning parts exists, but to what extent is the difference between a high quality steel bearing axle and a typical quality ceramic bearing axle actually meaningful? What is the percentage difference, not only in that single factor, but in the overall forces that are overcome in typical riding?

I guess my point is that there is a difference between a meaningful / significant / measurable improvement and a negligable / insignficant / not measurable improvement.

Feeling and theoretical physics don't tell me that it's actually significant. My "feeling" (and maybe someone has some data proving it wrong) is that it's such a tiny change it is totally meaningless compared to the real forces involved from air and gravity.

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