Ceramic bottom bracket vs. non-contact seal bearings

Triathlon Forum
1

A few days ago, I looked into the different options to upgrade my bike. After a bit research in the internet and also after a visit with a local bearing factory I would like to know about your experience with bearing upgrades. Before my visit and research with the factory I only new about the normal standard bearing in your bike and the ceramic upgrade. Well the marketing worked for sure, because I thought those are the only 2 different kind of bearings you could use in a bicycle.

However, after the owner of the bearing factory explained me, that instead of buying the really expensive ceramic bearings, I should look into the non-contact sealed (special low-friction seals), with a unique low-viscosity lubricant. I had the Shimano Dura Ace bottom bracket already with me and the difference between the DA bearings and the non-contact (no ceramic balls) sealed one was amazing. I took them with me to my local bike shop and everybody made huge eyes after I told them this bearings are not ceramic bearings. The mechanic’s in the shop thought I bought ceramic.

The research I did in the internet showed that you get about 4 free watt by the use of ceramic balls in your bearing, but I do believe you get the same out of this bearings as well without the huge price difference. I mean, all bearings are usually used in high turning machines and the ceramic once for extreme high turning. Well, even if you are super human you won’t make it for long with more than 200 RPM so I don’t think you will bring any of the bearings to the limit.

However, the start up torque penalty you pay with a normal bearing is “huge” compare to the non-contact seal which are designed for low torque applications.
So why still pay for a ceramic bearing? The non-contact seal bearings are made also in the size for your hubs. Same here, why upgrade to ceramic? Also the new Trent to the ceramic bearings in your headset? I don’t think it is worth the money like other athletes in this forum said in other posts.

The last thing what made me smile during my conversation with the owner of the bearing company was that he told me about a TEST done in Germany (I am from Germany) a few years back. He said that Porsche has the option to upgrade as well to ceramic bearings for an extra $5000…well the test showed that the ceramic bearings would only make sense once you reach the speed of 145 mph and up. Cool, so I don’t need that upgrade because I don’t know any place in Florida to drive that fast…lol

No, seriously what do you think about ceramic and how many of you heard about the non-contact sealed bearings with the special lubrication? Fact is, that I use them now in my Time Trial bike and the whole upgrade cost me less than $100. I went for a 100mile ride yesterday and I do believe there is a difference in the effort I have to put into my crank and the best part is that my wife still lets me sleep in the bed and not on the sofa because I didn’t spend again that much money for an upgrade. It took her a while to understand why I need a $6k bike plus the carbon rim set.

Thanks for your reply

2

You are a VERY smart man.

The difference in “feel” that most people experience with ceramic bearings in bike applications is basically ALL about the differences in seal drag.

3

Beautiful story. I need to find me a “bearing store.”

4

Well, I gotta admit, that’s the first I’ve ever heard of “non-contact seal bearings”.

Do you have a link to an example? Where would you buy such a bearing?

5

Wait, there is a trend of replacing headset bearings with ceramics? Why?

6

Wait, there is a trend of replacing headset bearings with ceramics? Why?

It’s for those really sharp turns where you need an instantaneous angular velocity of 20,000 rpm from your basebar. :-^

7

Wait, there is a trend of replacing headset bearings with ceramics? Why?

Exactly. Why?

I believe the quoted “advantage” is that it’s less likely to corrode…yeah right, like that’s a BIG issue with current headsets…yup, got those balls corroding with the races ALL the time…

8

+1, but dont forget about lubricant choice.

If you want to try and see what the differences are, remove the seals from your Shimano BB and repack with lighter grease. They will ride about like ceramic. No seals work great, but require very regular maintenance.

9

There are several factors giving resistance in ball bearings, ut til now this discussion has only touched 2 of the factors:

  • The seals “rubbing” (Will normally be reduced a bit by time)
  • The grease

Ceramic bearings do not change the first one (are produced in versions with normal(contact) and versions with non-contact seals.)
Ceramic bearings can normally be used with less/thinner grease then steel bearings.

2 factors where ceramic bearings might improve the resistance:

  • Roundness of balls (depends of course of quality, high-quality steel balls are rounder than low-quality ceramic balls - but high qualit ceramic balls are better than high-quality steel).
  • Hardness/flexibility of balls. I suppose non of us would prefer wooden or rubber balls i a bearing (even if they were completly round). Cheramic balls are harder (less flex) then steel, giving a clear advantage in bearings where high pressure is applied = bottom bracket.
10

There are several factors giving resistance in ball bearings, ut til now this discussion has only touched 2 of the factors:

  • The seals “rubbing” (Will normally be reduced a bit by time)
  • The grease

Ceramic bearings do not change the first one (are produced in versions with normal(contact) and versions with non-contact seals.)
Ceramic bearings can normally be used with less/thinner grease then steel bearings.

2 factors where ceramic bearings might improve the resistance:

  • Roundness of balls (depends of course of quality, high-quality steel balls are rounder than low-quality ceramic balls - but high qualit ceramic balls are better than high-quality steel).
  • Hardness/flexibility of balls. I suppose non of us would prefer wooden or rubber balls i a bearing (even if they were completly round). Cheramic balls are harder (less flex) then steel, giving a clear advantage in bearings where high pressure is applied = bottom bracket.

Possibly…but the difference in power losses for equivalently sealed BBs is measured in milliwatts, not watts, even when running a lighter lubricant…so, what’s the point?

11

Yes, one very important aspect for a bearing is the lubrication the other the friction you have while cranking your RPM caused by the seal.
Well, like I said the non-contact seal does 100% do the job for me and those once are so affordable already with the good lubrication that I wouldn’t repack any of my bearings.

However, it is right that the ceramic bearing balls are much rounder etc, but if it doesn’t make a difference in the Porsche if you just driving it around town, it will 100% make NOT a different to me riding my bike. The balls in a bearing change form with heat and very high RPM (+18.000) and cause than more friction. Well, that happens at about 250 degree Fahrenheit. Is that correct? If so, I won’t be on my bike and I could care less. So far, I don’t see a reason to use ceramic bearings instead of the non-contact seal bearings nor would I recommend it to any of my friends, but I would always change the bearing to a non-contact seal bearing.

12

Yes, one very important aspect for a bearing is the lubrication the other the friction you have while cranking your RPM caused by the seal.
Well, like I said the non-contact seal does 100% do the job for me and those once are so affordable already with the good lubrication that I wouldn’t repack any of my bearings.

However, it is right that the ceramic bearing balls are much rounder etc, but if it doesn’t make a difference in the Porsche if you just driving it around town, it will 100% make NOT a different to me riding my bike. The balls in a bearing change form with heat and very high RPM (+18.000) and cause than more friction. Well, that happens at about 250 degree Fahrenheit. Is that correct? If so, I won’t be on my bike and I could care less. So far, I don’t see a reason to use ceramic bearings instead of the non-contact seal bearings nor would I recommend it to any of my friends, but I would always change the bearing to a non-contact seal bearing.

Exactly.

One other point to make is that ball bearings are not necessarily the best bearing design for a BB bracket, ceramic or otherwise. A much better design for the application (low speed, high load) is a roller bearing. That’s why the DuraAce Octalink BB is comprised of roller bearings to take up the large radial loading (and spread it over a LARGE race area) combined with relatively small balls to accommodate the smaller axial loads…of course, all in a package that allows you to actually adjust the preload of the bearings for best operation. Both of my bikes (road and TT) have the DA octalink BB.

To take it even further, IMHO balls in a headset are sort of silly. Tapered roller bearings would be much more appropriate for the application. But, in this day of cartridge bearings, I’m sure that balls are the cheapest, and seem to work OK. However, to compound that silliness with making the balls out of ceramic…well, that’s just DOUBLE silly! :wink:

13

Good info. Does anyone know where to buy these bearings or lubricants? I frequently replace the cartridge bearings in my BB and wheels with ordinary industrial bearings and know how to pull the seals out and relube, but how do you buy low friction seals?

14

Help a noob out:

So the change you made was a non contact seal, lubricant, and ball bearings made to work with a non contact seal?

are their downsides to this setup? more regular maintenance needed?

where would one obtain these items and how do you set it up/install it?

15

The research I did in the internet showed that you get about 4 free watt by the use of ceramic balls in your bearing I think the ‘4 free watt’ claim is not even close to reality. I’ve seen other claims that put it ‘400 times’ better or some nonsense–but 400 times nothing is still nothing. I’ve yet to see any documentation that shows a BB takes more than a single watt to spin…
No, seriously what do you think about ceramic and how many of you heard about the non-contact sealed bearings with the special lubrication?
I’d be curious about how a non-contact sealed bearing would hold up in a wet climate. Obviously it would depend on the seal, but I’d be suspicious (though I’d like to hear your experience). I’m the biggest hater there is when it comes to ceramic bearings for bicycles, but after having my last DA bottom bracket last about 2 weeks before it started making a ton of noise, I decided to try a cheap ceramic BB (I was happily using the Enduro steel bearings, but unfortunately they didn’t work with my SRM). It’s been noise-free for about 4 months, and that’s really my only requirement for a BB, since I don’t think the rolling resistance differences are substantive. If I were buying a new bottom bracket right now, I’d probably try the Chris King BB. I figure if it took this long to get on the market, they must have done an OK job with it.

16

The research I did in the internet showed that you get about 4 free watt by the use of ceramic balls in your bearing I think the ‘4 free watt’ claim is not even close to reality. I’ve seen other claims that put it ‘400 times’ better or some nonsense–but 400 times nothing is still nothing. I’ve yet to see any documentation that shows a BB takes more than a single watt to spin…
No, seriously what do you think about ceramic and how many of you heard about the non-contact sealed bearings with the special lubrication?
I’d be curious about how a non-contact sealed bearing would hold up in a wet climate. Obviously it would depend on the seal, but I’d be suspicious (though I’d like to hear your experience). I’m the biggest hater there is when it comes to ceramic bearings for bicycles, but after having my last DA bottom bracket last about 2 weeks before it started making a ton of noise, I decided to try a cheap ceramic BB (I was happily using the Enduro steel bearings, but unfortunately they didn’t work with my SRM). It’s been noise-free for about 4 months, and that’s really my only requirement for a BB, since I don’t think the rolling resistance differences are substantive. If I were buying a new bottom bracket right now, I’d probably try the Chris King BB. I figure if it took this long to get on the market, they must have done an OK job with it.
I went to a ceramic BB for the same reason you did, I wrecked two bottom brackets and my LBS recommended that I try a ceramic (which they sold me at cost). Since then I have had no issues and it requires less maintenance then my previous bearing BB. I don’t know how much watts it saves, but even 18 months and almost 2000mi old it is smoother then almost any steel bearing BB I have used (except Phil Wood). I do want to try a CK when this one needs replacement.

17

Word. I wasted darn near a whole day at work researching ceramic hubs and BBs, and the more I learned, the more I started to suspect that ceramic bearings are a giant bike industry boondoggle designed to increase profit margins. I couldn’t find any convincing evidence that they do f-all in real-world conditions.

My favorite was some guy who tested Zipp’s Z4, and posted this to Zipp’s forum (http://www.zipp.com/support/askjosh/hubs.php#):

I’ve now done 7 head-to-head rolling resistance trials between a Zipp 404 and a Z4 on 3 separate days. I’ve been looking for that extra watt or so that ceramic bearing advocates claim.
The Z4 has lost all the trials except one. The average difference is .00009 Crr – or about 1 watt at TT speeds.
Here are some test details: Tests were on rollers with front wheel stand and power measured with SRM professionalWheels were swapped on alternate runsTest speeds varied between 30 and 35mphTires are same make and model. However, the tire on the 404 has a bump in it (that should make it slower, right?)The 404 tire has been glued on for several months longer with the same adhesive (albeit slightly different technique). The Z4, incidentally, has not improved in the 3 weeks since it was originally glued.
I really wanted to see an improvement with the Z4s. But it looks like adhesive technique and curing time may affect your wheel’s performance more than highfalutin’, expensive ceramic bearings… **************************************

And the ever smooth-talking “JoshAtZipp’s” response is just absolutely classic:

“I think that Jens’ study is great and really shows just how far we have come with steel bearings in the last 4 or 5 years…”

Damn, that’s straight up Karl Rove-caliber spin, right there.

After studying these things I will never again trust any number I see coming from Zipp or FSA, except the prices.

HED was honest and says this about their tests, “There was a measurable drag difference between ceramic bearings and steel bearings when we tested unloaded wheels, but the difference was small enough that we could not measure it on a loaded wheel.” I.e., ceramic means f-all in the real world. That, so far, is my conclusion on these things, given that there is a real shortage of publicly available independent testing data.

I think the ‘4 free watt’ claim is not even close to reality. I’ve seen other claims that put it ‘400 times’ better or some nonsense–but 400 times nothing is still nothing. I’ve yet to see any documentation that shows a BB takes more than a single watt to spin…

18

Where did you get the non-contact bearings?

19

sven,

email me on where you got your non-contact seal bearing. i’ve read that steel balls are the weak link in a bearing for the reason that grime and dirt can wear the steel ball which causes the eventual breakdown process of the ball. ceramic balls are so hard, they crush dirt w/o the damage. for the high cost of conventional ceramics in cycling its probably not worth the uncertainty of any speed benefit. faster or not, in my head i’m a teeeny bit speedier because of my ceramic BB and pulleys - nearly 2yrs and thousands of miles later w/o any noises or issues. lets design and market ceramic chain links… ha ha ha!

21

Wait, there is a trend of replacing headset bearings with ceramics? Why?

Exactly. Why?

Why? Because people will pay for them. It’s pretty simple, really.