Ceramic bearing q'n

I don't want to be a misery guts, but for the forces invoved it's just a way of getting you to part with your hard earned cash!

I don't think there would be any any measurable benefit.

Is this a racing bike or a mountain bike....are you using it on road or off road.

Most important factor sfter the wind resistance is weight, especially of the wheels.

Send me the $200 and I'll send you a special ceramic crystal with magnetic properties which will reduce your wind resistance by 10% (and stop your shower heads getting furred up) ! ......(Joke...terms and conditions apply...not available to anyone of a nervous disposition )

I realize that at first it looks like a foolish thing to do, but here's why i don't think so.

- Firstly due to the fact that ceramic balls are being made in a affordable price in grade 5 which is real good (read: real round) and compared to a steel ball wich is usually grade 25 it means that ceramic balls are much rounder and there for the wheel/hub rolls much better. This means with less effort the same performance or with the same effort more performance.

- Secondly there is no need for large amounts of grease (drag) and that will decrease the effort to move forward with each pedal stroke.

No matter how one looks at it there is a benefit to be had if going to ceramics.

Yes, there is a price to pay, but how many people ride with a carbon fibre water bottle holder for $$$ and a lousy x grams lighter.

When you're a bit involved in cycling that you know that weight on flat roads is nothing but bla, bla. Up hill is a different story, but even then it's for the average rider just a waist of money.

This however is not the case with ceramics as they make something that is relatively ok (bearings on a bicycle) better and in some cases much better.

Now compare the price of a carbon water bottle holder to a set of ceramic (balls) bearings.

Which is the best choice that gives a real positive effect ... :-)

Ceramics are a improvement it's just up to the level of perfection of the rider where he/she wants to end.

It looks like you have answered your own question .

No, not so.

My starting topic hasn't been answered yet or at least not all of it

Boca Bearings in Boce Raton, FL USA

These folks are the experts and they do things that are far more complicated than this. Get on thier web site and email them, they are the best for this application.

h2om@hotmail.com

There would be no problem with hybrid bearings a low rpm.

All bearings preform longer if lubricated. The grease recommended for hybrids is lighter lower viscosity.

Many competitors i believe are running these bearings dry or with a light oil.

Depends on the type of punishment placed on bearing. If mountain biking i say yes. If street racing a standard race would be okay. Have not seen a Extra Harden race listed. standard races are pretty hard.

Unsure what grades you are questioning please be more informative. Bearings are graded due to the clearance tolerances between the balls and the races. The less the clearance the truer the bearing runs. But this reduces top end speed. Because a ceramic ball can be finished to a more spherical shape you can get higher top end speeds in the same grades with steel balls.

That is what i thought too, but the problem is that so far no one even the bearing companies couldn't answer that q'n if i should need any lube for low rpm as almost all of the focus is on industrial applications and no cycling specs.

I certainly accept the fact that pro's do ride with no lube or very little as they are being sponsored and the result is what counts.

Sadly for me this is not the case so i have to be sure by test results and not just marketing bla, bla.

I there for have to find good solid information on the tech.specs of these items and that is where so far the problem is.

I'm not willing to spend a lot of money because some sales rep. tells me it is ok and can't back it up with test results cycling specific.

As far as my information has brought me is that there is a definite need to re harden the races as the full ceramic balls are of a higher hardness grade than the average steel ball. So when putting ceramic balls in standard races than you have a low priced hybrid bearing, but problems on your hand very soon no doubt. Again you get what you pay for like so many people tell and have experienced that i'm afraid.

In fact due to this i decided not going for the DA hubs (with ball cup/cone), but instead for the DT hubs as they have industrial kind of bearings so there's allways a option what to fit and no damage what so ever to the hub itself.

The only company that is explaining it far better than any of the bearing manufactures is a usa based enduro. They give a rather good in easy to understand explanation on what is what and why things have been done.

With all the reply's of everybody and the lack of good solid info on full ceramics my preference so far is for the hybrid version as these are relatively affordable and the performance gain is better to much better than the average steel bearing now being used.

Maybe it could be that the performance gain between a full ceramic bearing and a hybrid one is far less than from steel to hybrid, but again time has to be the judge on this one as tests will be there to read i'm sure.

I think due to the fact that it is all rather new more testing has to be done especially cycling and maybe than the answers i haven't found yet will be more available and no doubt than i and many others will be able to make a far better decision going the full or hybrid version.

Also too many sellers give different advice on the type of grease for ceramic/hybrid bearings and that only confirms my doubts.

I think there will be a lot of trail and error happening even by customers to find what is the best grease and what not, but one can't put clients of with the same grease that is/was working for steel bearings as this would be just as doubtfull as using gasoline in a diesel engine.

I'm cool with all the advantages in friction, brinneling, etc., but what about durability? Do these things turn to powder with mountain-bike-like shock? I'm looking for bearings for a different purpose, but similar requirements, and I'm more concerned about the longevity in harsh conditions than about the cost.

Molybdenum disulfide would be your best bet as a dry powder, purer the better.

low drag very thin film. The ceramic bearings don't need cooling just high pressure lubrication. (Dad,s 25 years in custom lubrication)

I had problems with bearings on my bike: the solution I found best was sealed units - no need for maintenance, and factory set tolerances are better than I could achieve/maintain myself.

The biggest cause of bearing wear is incorrect endfloat, which is very difficult to set up accurately at home - especially when the bike is carrying 130kg+ ( me, 1 child and rucksack)

This is mainly conjecture, but I think the main advantage of a ceramic bearing it it very high stiffness, so the the balls deflect less under load. However, the point contact of a ball on race becomes line contact (and then elliptical contact) as the load increases. As soon as the contact goes to line contact, then there is a need for lubrication, because the "sides" of the ball are skidding along the race, to some degree.

The drag from lube would be a small portion of the drag on a heavily loaded bearing (and would be relatively constant, and relatively independent of load). The drag from deformation and skidding under high load would be higher, I'd think. So it seems that a very low viscosity lube (dry?) would be beneficial. Measured at the pedal, I'd guess drag from lube might add a couple grams of resistance, regardless of crank speed. Drag from bearing deflection, skidding, etc., is more likely to be tens of grams, I think. (And of course the force you apply to overcome tire rolling resistance, aero drag, hill climbing, etc, is thousands of times higher -- many kilograms.)

As you probably know, there is no relationship between the apparent drag of two bearings when spun by hand vs under load: A bearing that feels "tight" when turned by hand may have lower drag (in loaded operation) than one that spins easily.

But, in any case, a bearing manufacturer could tell you more. The bearings on which the wing pivots in the boat in my avatar are steel, but ceramic was a possibility due to their resistance to corrosion. (The standard sailing bearing, delrin or torlon balls on alu races, was much too soft.) So I don't have any real experience with ceramics -- it's all hearsay.

Ah,

Ken, your opinion maybe hearsay...mine was obviously heresy!

Thanks everybody for your input as this is a learn full discussion

The thing that i haven't figured out is this.

I do understand that it would be best to use a either steel or ceramic ball in the lowest grade possible. So a grade 1 is superb, 3 less superb, 5 very, very good etc.

BUT, what i don't know if this is the same for the races (used in hybrid bearings).

Is a grade 1 races also the best or must this be higher say a grade 25 is superb, grade 20 less superb.

I search alll over, but can't find a good explanation.