Ceramic bearings: better in rainy situations?

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

Is using ceramic bearings (i.e. in wheels, BB) better when biking in rainy condition?

Here my thoughts...I am not sure I am right...
- From one side, there are usually no sealing lip in order to have a "free" rotation, so that would allow the water to get easier inside. Unfortunately maybe also some fine particles...
- From the other side, the ceramic bearings don't need grease so even with some water inside they should long laster. If however some particles also enter, then it is of course that would not be that good.
- So the summary, as usually with the rain you have also much small particles in the rain etc... the ceramic bearings would be less good than conventional bearings (that you have to service regularly however)

What do you think?

by Weenie


JackRussellRacing
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Location: North Carolina, USA

by JackRussellRacing

I run Kogel bearings (BB and jockey wheels). They specifically make a version of their products for "less than ideal" riding environments : https://www.kogel.cc/blogs/kbba/the-bes ... ur-journey


.. and BTW, I rode alongside Ard Kessels (Kogel bearings founder) recently on a charity thing here in North Carolina. It was mucho coolness.

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TonyM
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by TonyM

That sounds interesting with the "cross seal version". It would make this ceramic bearings like the "regular" setting with the seal.

But would the ceramic bearings be let's say better in terms of longevity compared to the Dura Ace/ XTR bearings when they are used in rainy situations?

Hexsense
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by Hexsense

It's maybe.
Most ceramic bearings for bike are actually hybrid ceramic bearings. Balls are now ceramic instead of steel or stainless steel but the race is still stainless steel not ceramic. Full ceramic bearing are too fragile for impact crack so hybrid is the way to go. If you have a condition bad enough for stainless steel balls to rust, stainless steel race will also rust no matter what material the ball made of.

So, Ceramic ball bearing alone doesn't make it condition proof. The race become their weak point that need to also gain durability.
Last edited by Hexsense on Wed Sep 27, 2017 9:03 pm, edited 1 time in total.

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TonyM
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by TonyM

Hexsense wrote:It's maybe.
Most ceramic bearings for bike are actually hybrid ceramic bearings. Balls are now ceramic instead of steel or stainless steel but the race is still stainless steel not ceramic. Full ceramic bearing are too fragile for impact crack so hybrid is the way to go. If you have a condition bad enough for stainless steel balls to rust, stainless steel race will also rust no matter what material the ball made of.

So, Ceramic bearing alone doesn't make it condition proof. The race become their weak point that need to also gain durability.


Good point! :thumbup: I forgot the race itself indeed...

AJS914
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by AJS914

A bigger difference may be how you lubricate them. Some manufacturers like Campy recommend only a light oil for ceramic bearings. Grease might give you greater longevity between servicing in wet conditions. I think it also depends on whether you have a cutout in your bottom bracket and are getting any water in there during rides.

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TonyM
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by TonyM

AJS914 wrote:A bigger difference may be how you lubricate them. Some manufacturers like Campy recommend only a light oil for ceramic bearings. Grease might give you greater longevity between servicing in wet conditions. I think it also depends on whether you have a cutout in your bottom bracket and are getting any water in there during rides.


What do you mean with a cutout in the BB?

AJS914
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by AJS914

A hole in the BB shell where water and grit can enter and get at the BB - like in the C60 or my C59.

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TonyM
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by TonyM

AJS914 wrote:A hole in the BB shell where water and grit can enter and get at the BB - like in the C60 or my C59.


You mean under the BB in the frame?
I have one hole also in my C60 there which I actually taped 80% in order to avoid the water etc.. coming into but still having some ventilation.

11.4
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by 11.4

First, as pointed out once above, cycling uses hybrid bearings when they go ceramic -- the races are steel, the balls are ceramic. So lubrication is definitely required and is defined in the spec of most ceramic products.

Second, it's more often the races than the bearings that actually go bad. Even with steel bearings, you had to go back thirty years to find bearings of such poor metallurgy that they'd flatten or crack. If you examine a bad bearing, whether headset or bottom bracket or whatever, it's usually the races that have gone bad and have pits (typically if there's limited rotation, as in a headset) or rough grooves (for the other applications).

Third, seals are basically the same for most components, whether bearings are ceramic or steel.

Next, ceramic bearings today are extremely durable (early versions weren't, and tended to crack too easily). They can take everything you can throw at them including water, grit, and so on. However, you still have the races to deal with, so ..........

Also, one of the benefits of ceramics is that the bearings can be made much more perfectly round (or any other shape you need) compared to steel. Go to YouTube and watch some videos of ceramic bearings being made -- they are spun on air jets as they're being made, so they attain symmetry beyond what can be done with steel. That's really why you get those slight wattage savings when going with ceramic bearings. (It's also why you benefit from going to oversize jockey wheels with oversize bearings, because the bigger the bearings, the less sensitive you are to minute irregularities in the bearings or the races.)

You asked if ceramic bearings were better in rainy conditions. Because it's only the bearings that are being replaced for steel, it's not a lot of weight savings. The ceramic bearings are going to be, if anything, a fair bit more durable than steel bearings, but it's likely the races that will go first anyway, so that doesn't amount to much. Both types of bearings need lubrication and typically have similar sealing. The ceramic bearings will save you a couple watts, but in the rain you'll be losing that elsewhere. In short, I'm not sure I see the benefit you're looking for. Especially when you have to pay a good bit more for it. If those two or three watts are really the difference for you between winning and losing, then yes, go for it. Your pro team will replace the bearings as quickly as is needed and will pick up the bill. For most people, ceramic bearings won't hurt, but they don't do much. Even less so in the rain.

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TonyM
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by TonyM

11.4 wrote:First, as pointed out once above, cycling uses hybrid bearings when they go ceramic -- the races are steel, the balls are ceramic. So lubrication is definitely required and is defined in the spec of most ceramic products.

Second, it's more often the races than the bearings that actually go bad. Even with steel bearings, you had to go back thirty years to find bearings of such poor metallurgy that they'd flatten or crack. If you examine a bad bearing, whether headset or bottom bracket or whatever, it's usually the races that have gone bad and have pits (typically if there's limited rotation, as in a headset) or rough grooves (for the other applications).

Third, seals are basically the same for most components, whether bearings are ceramic or steel.

Next, ceramic bearings today are extremely durable (early versions weren't, and tended to crack too easily). They can take everything you can throw at them including water, grit, and so on. However, you still have the races to deal with, so ..........

Also, one of the benefits of ceramics is that the bearings can be made much more perfectly round (or any other shape you need) compared to steel. Go to YouTube and watch some videos of ceramic bearings being made -- they are spun on air jets as they're being made, so they attain symmetry beyond what can be done with steel. That's really why you get those slight wattage savings when going with ceramic bearings. (It's also why you benefit from going to oversize jockey wheels with oversize bearings, because the bigger the bearings, the less sensitive you are to minute irregularities in the bearings or the races.)

You asked if ceramic bearings were better in rainy conditions. Because it's only the bearings that are being replaced for steel, it's not a lot of weight savings. The ceramic bearings are going to be, if anything, a fair bit more durable than steel bearings, but it's likely the races that will go first anyway, so that doesn't amount to much. Both types of bearings need lubrication and typically have similar sealing. The ceramic bearings will save you a couple watts, but in the rain you'll be losing that elsewhere. In short, I'm not sure I see the benefit you're looking for. Especially when you have to pay a good bit more for it. If those two or three watts are really the difference for you between winning and losing, then yes, go for it. Your pro team will replace the bearings as quickly as is needed and will pick up the bill. For most people, ceramic bearings won't hurt, but they don't do much. Even less so in the rain.

Thanks for the clarification! :thumbup:


That means that for rainy weather either regular bearings or ceramic bearings BUT then they have to have a proper seal (as I understand that some manufacturers removed the seal in order to achieve less friction), right?

But how do I know if a wheelset have a proper seal or not (if they have ceramic bearings)?
for example the Roval CLX 50 Disc ("Roval AFD1/ AFD2 hubs with CeramicSpeed bearings")

hambini
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by hambini

Ceramic bearings are almost always C3 clearance, whether they state this or not is a different matter. If you measure them (and I do) they all come out minimum C3 and often higher than that. If you are not familiar with the bearing clearance, i have written a technical article here

https://www.hambini.com/technical-support/bearings.html

Most of the guidance that other forum members have given you here is valid but I thought I would chirp in with my points.

1. Ceramic bearings are hybrid, the balls are rock hard, the steel not so. They wear out quickly.
2. Due to the increased bearing clearance, they tend to have slightly more friction under load than a decent steel bearing
3. The seals come in two types, contact and non contact. The vast majority of friction comes from here. I would go for full contact if you were riding regularly in the rain or be prepared to change them frequently.
4. If you are riding in the rain, you will find your races die before anything else.

Here's a video on ceramic vs steel - I'm firmly in the steel camp because the speeds involved on a bike do not warrant a ceramic bearing.

https://youtu.be/o7iZVfSDbiA

Hope that helps

Hambini

bm0p700f
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by bm0p700f

It turns out the above is true and not. Take campagnolo cult bearings. The steel races used in those are very wear and corrosion resistant and will tollerate any weather for quite some time. Given the exhoritant cost though its not worth it. For wet weather there is nothing better than a square thaper bb. If gou worry about drag square tapers spin more freely too.

Like all things ceramic bearing are not created equal. This does not meN they are worth it.

hambini
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by hambini

bm0p700f wrote:It turns out the above is true and not. Take campagnolo cult bearings. The steel races used in those are very wear and corrosion resistant and will tollerate any weather for quite some time. Given the exhoritant cost though its not worth it. For wet weather there is nothing better than a square thaper bb. If gou worry about drag square tapers spin more freely too.

Like all things ceramic bearing are not created equal. This does not meN they are worth it.



The campag cult is actually a surface treatment made by FAG (Schaeffler), it was not designed for the application that campag use it on which is an angular contact (cup/cone) bearing. The herzian contact stress that's applied causes it to ripple and it breaks down just like everything else.

Originally the FAG coating was for use with steel bearings in food service (ie no lubrication).

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TonyM
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by TonyM

Thanks for the additional information! :thumbup:

What about the DT Swiss hubs with their SINC ceramic bearings? it seems they have a proper seal which would make them ok or good for a use in rainy conditions, right?
https://www.dtswiss.com/en/technology/w ... echnology/

I am also looking at the Dura Ace R9100/R9170 wheelsets. Unfortunately I could find any information on their hubs, bearings and seals.
I suppose they have proper seals and steel bearings, right?

by Weenie


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