NoWhammies

I recently replaced the bearings in my rear wheel as well as in my bottom bracket. I replaced like-for-like, but in speaking with the fellow from the LBS he mentioned ceramic bearings. His comment was I may want to think about using ceramic bearings the next go around.

So here I am, posting so see what forum members think of ceramic bearings. Are they worth the added costs? Do they last longer? Etc. Thanks.

JohnDThompson 

Bicycles are not a heavy-duty application for bearings, so any advantage is likely to be minimal. You could overhaul and replace your bearings several times for the cost of a set of ceramic bearings. Unless someone else is paying for them (e.g. sponsored team), I'd pass.

horatio 

The bearings are too hard for the races, according to an aerospace engineer.

Marcus_Ti

They don't really net you much in the real world, especially given the cost.

OTOH some very nice hubsets come with them anyway, and would still be nice hubsets even with plain-old steel bearings.

DrIsotope

In the R/C world, ceramic bearings are a necessity for many brushless motors-- I have several motors that will spin to 80,000+ RPM. I can't see any bearing on a bike ever exceeding even 500rpm.

Buy steel, replace them as often as you like. The typical cartridges used in bicycles can be had for $2-3 each, and will last thousands if not tens of thousands of miles.

If you want the absolute in chasing marginal gains, pull the seals out of the bearings, flush out the grease, and replace with a lightweight bearing oil.

Yeah, you'll have to re-oil before every ride, and the bearing life will be drastically reduced, but you're sure to free up a few watts.

Troul 

The benefit I can see is that it would reduce the chance at creating corrosion, especially when the bicycle is not being used for lengths of times.

smarkinson

I think most of the benefit is the bigger profit margins for the LBS.

studbike1

don't waste your money.

the internals only last as long as the seals. once that seal is compromised, the bearing is going to fail soon thereafter no matter what.

it's a different discussion when dealing with high-speed machine bearings. they spin really fast, at constant speeds, for hours on end, and usually are not exposed to the elements. all of that tilts the balance towards wear-and-tear of the internals.

Wilfred Laurier

I don't find this to be an issue on any reasonably well sealed loose bearing set (esp. Shimano labyrinth sealed hubs) that has been properly lubricated. You might be amazed at the destroyed and gunked up drivetrains that, when disassembled, reveal clean grease in the hub bearings.

wphamilton

Personally I'd take the ceramic bearings suggestion as a joke, so as not to be offended by it.

dmanthree

I tried a set of wheels with ceramic bearings. It's marketing, nothing more. Pass.

caloso

There's a bit of weight lightening. Unfortunately, it's all in your wallet.

Doge

I do both - a lot. It is not just the bearing, it is the market they are after and what comes with it. Many ceramic bearings use very light oil and non-contact seals. If you did that on steel you would feel a difference. I can't find that in steel. They are also lighter. Every time ours are used in rain or grit, or someone washes the bike with a sprayer - things get ruined.

Way back in the loose ball days, light oil on steel good bearings would spin really free. But I'm not doing loose balls anymore. Many ceramic bearings are hybrid with ceramic balls and steel races. These press in better. I think those are more suitable for hubs.

Anyway, yes - they make a huge difference is a very small area. So net might be a few watts - <1%, but it all adds up. I'd focus on RD pulleys first - mostly for seals. But the difference is huge compared to other pulleys, but insignificant in the whole bike system.

I'm made fun of often for my little bit here and there (on kid's setup) and then folks complain that he had an unfair advantage.

Edit/Add: My kids climbing bike/my hobby saves around 10-15W total on chain, pulleys, BB, pedals, hubs over std "pro" setup. I also disassemble and re-do the freewheel. I believe, he believes, it makes a difference. It may not. But in many Strava segments riders of equal mass show much more power and go no faster. Most of that, I expect is he has a hub meter and they have pedal ones. That also speaks to friction loss.


As much of cycling is about art and emotion, then sure, save a few grams reduce bearing friction by 50% or more depending on where you use them and have fun. I doubt you will feel it. But you might.

Doge

I watched this after my last post. He makes assumptions that we are dealing with hybrid and BB and hubs.

The BB data for Enduro Ceramic (what I use) is .13W vs .48W. ~300-~400% - huge.
He made the point on seals - yes. Seals he shows are 60%. And the cage. Just that if you want non-contact seals - you buy ceramic, or swap them.
His illustration was a larger steel bearing with steel cage. The best ones are a plastic variant - maybe Teflon. So IMO he briefly mentions the most important stuff and went on to meaningless stuff.
He is misguided, or misguiding.

FULL (inner, outer race and bearings) Ceramic RD pulleys are barely under load.

Want to save friction? Then 1st buy a Shimano Dura-Ace chain. Second - buy cheap full ceramic pulleys. Next the BB and then the hubs. Do all and you may notice.

Homebrew01

Damn, beat me to it

Marcus_Ti

So you save 3/10ths of a Watt in the context of a system with 100s of watts of aerodynamic resistance. Absolutely huge.

Doge

His numbers are deceiving. A Ceramic BB vs a Steel one is more like 3-6W. That 3/10th watt due to seals, not bearings. That part was addressed in the video, but largely ignored.

My post before makes it clear that it is a huge difference on a small thing.

In an ITT - all ceramic vs steel can be worth a couple places. If you care about that stuff it matters. Again, not due to ceramic or bearings, but due to the other stuff that you get with them - no seals, loose etc.

I don't buy Ceramic Speed as I don't think it is worth it, but happy to spend $20 for full ceramic pulleys. I pay about $40 more for the Wheels Mfg ceramic bearings shown.

There was a company called "Friction Facts" that used to test all this stuff. They were bought by Ceramic Speed. Pulleys 1.337 W between least and most efficient. Pedals 1.2W difference. 3-4W on chain then - and more now. The Dura-Ace chain is about 5W, others are 10W.

Anyway add it all up and you get over 10W. Many can feel 10W.

Doge

1st vs 2nd or 3rd place in an ITT.

Obviously this is a performance thread. If you are just tooling around, why would you care.​​​​​​ If you want to get to work faster - get a motor.

Context. Guy on top had ceramic bearings. 2nd, a later world junior ITT champion and new WT contract rider didn't. The difference was .6 sec.
HUGE difference to me, easily worth the $100.
YMMV.

TiHabanero

If durability is the goal, keep the traditional hub serviced and it will last tens of thousands of miles. For example, I have a hub set from 1986, Campy NR, with at least 50,000 miles on them, and they are still spinning along beautifully. The hubs don't even have seals. I service them once a year now, but back when I was racing on them I serviced them once every two months, but was hammering the miles rain or shine. Honestly, they spin as well as the DT Swiss 350 hubs I got this summer. Still using the original balls, too. Smooth as a baby's rear end!

If speed in fractions of a second over a 20 mile or whatever course is the concern, then you just may benefit from them, but honestly, I doubt you will win any races because you are running ceramic bearings. What JohnDThompson said just makes sense.

HTupolev

What?

Not a useful way of approaching the issue. A common theme with friction tests is that there'll be a few items that perform extremely badly on the slow end, but most things will be closely-spaced. For instance, in the 2013 FrictionFacts BB test, the slowest BB was about half a watt slower than the second-slowest, but about the top 2/3rds the BBs all performed within half a watt of each other.

So unless you're in the rather terrible situation of always using the absolutely slowest parts on everything, realistic gains tend to be tiny compared with what a "best versus worst" comparison might suggest.

Clem von Jones

The ceramic-bearing-titanium-spindle square taper bottom brackets are 160g compared to 250-330g for typical BBs but I suspect they aren't as durable. I'm tempted to try one though. The bearing races are metal so it doesn't really solve the corrosion problem.

Doge

I thought what I typed was clear. I'll repeat - it is not the bearings as much as the seals and grease and cages. But the net result is if you buy a Wheels Mfg Ceramic BB - you will see 3-4 W difference over the Shimano
on my desk that I just took a picture of for you. Actually, I can't speak to that one as it is NIB, but I have replaced others. If I don't replace I cut out the seal dragging on the inner race.

This



vs This





Here are bigger claims - I am not making.
When added to the full CeramicSpeed component upgrade (the OSPW System, Bottom Bracket and Wheel Kit), chain optimisation can take the total saving to between 10-16 watts.
https://www.ceramicspeed.com/en/cycl...n-shimano-11s/

Doge

Pulleys do not take much load. A ceramic pulley here. It has light oil and non contact seals.

HTupolev

What you typed was clear, what's unclear is where the 3-4 watts claim comes from and what its context is.

Koyote

I think what is clear is that the poster is citing data provided by the very same companies that are selling the expensive ceramic bearings.