ryan.karr22

Is it possible to up grade cup and cone bearings with ceramic balls, and what grease is the fastest? I looked for upgrade parts for my Shimano hubs and all i could find where sealed bearings. where should i start looking?

Mark Kelly 

It is perfectly possible to replace the steel balls with ceramic ones. Just buy the appropriate number of Si3N4 balls in the correct size and grade from the likes of Boca Bearing

IMO you are wasting your time and money, but they're yours to waste so go ahead.

BikeWise1

Waste of time and money. AS IF the races in the hubs are anywhere smooth and round enough to be able to exploit the tolerances of ceramic balls.

Sixty Fiver

Possible - yes.

Practical - no

531phile 

badamsjr

There are some sellers on ebay who list different size SI3N4 balls in Grade5. Enduro Fork Seals sells 'web grease' which is formulated to cling to the smoother surfaces of ceramics. MANY will tell you it is a waste of money to do this, but FEW have actually done it themselves, so are only giving you their opinion on it. I have done it, and like the result. As always, YMMV.

Sixty Fiver

I see at least two mechanics here with nearly as much experience between them as you are old saying that ceramics aren't worth it and the only mechanics I know who have suggested using ceramics have had a financial interest in performing this upgrade.

If you have money to burn and need a marginal upgrade in performance then go for it... am quite sure the benefit people perceive stems from the fact they go from their old hubs to new ones that are fitted with ceramic bearings so there will be an improvement.

I use grade 25 steel bearings and my wheels spin forever... a grade 5 ceramic won't improve that by any noticeable degree.

ryan.karr22

all good advice. Thank you

DannoXYZ 

Heh, heh... I was a mechanic for 10-years and I'll add my very well-backed and researched opinion that while there may be measureable improvements with ceramic bearings (needs a lab environment), those improvements are so negligible in real-world conditions that it's IS a waste of time & money.

I also raced bikes for 10-years and got to cat-2 on road and cat-3 on track. There's a 10-mile TT course here that I can do back-to-back runs within 5-seconds of each other. Just for giggles, I did two runs within 1-hour using wheels with grade-25 steel balls and an identical set of wheels with ceramic balls. My times were roughly the same, the improvements were less than the confidence-window of my TT runs. In fact, I bet if I took one drink of water during this TT, it would skew the times more than what you'd gain from ceramic bearings.

Remember that you have compare like-for-like. Brand-new grade-25 or even 100 steel balls with new grease adjusted optimally compared to brand-new ceramic balls. You can't take crusty 10-year old dried out hubs and re-pack them with new grease and ceramic balls and call that a valid comparison. Because there WILL be a noticeable difference in this case, but that difference would be the same if you rebuilt with steel balls as well.

badamsjr

So what you are saying is that you would have to rebuild steel ball bearings to make them comparable to ceramics? Performance is only PART of why ceramics are superior to steel balls IMHO. The fact that they are harder, smoother, and less 'corodable' than steel only increases their advantage. Again MY OPINION.
In spite of all the conspiracy theorists who think the bearing companies are only out to 'fool' us about the 'suposed' advantages of ceramics, I find it real hard to believe that the top race teams in the world are only using ceramics because they are free (by sponsorship). It seems MUCH more likely that they realize there is a performance advantage (however small) to be gained with them.
"Let the flames begin"

badamsjr

I'm curious--do you use knobby tires on your road bikes that are ridden on pavement? On a much larger scale, this is the advice you are giving for bearings.

FBinNY 

Ceramic bearings do lower friction, hybrid bearings (ceramic balls in steel races) also do but to a lesser degree.


BUT ---- You need to maintain a bit of perspective before plunking down your cash.

Energy loss to bearing friction is the smallest part of the total drag on a bicycle. It's much smaller than power loss to the chain drive, and the tire rolling resistance. More important it's a constant, so you can see and feel how tiny it is on a free spinning wheel.

Compare that to the total energy involved in wind drag, which is proportional to the square of speed, and even at a moderate 15mph already accounts for the vast majority of your power requirement, and you'll realize that the benefit of ceramic bearings to your performance is comparable to lowering your mortgage payment by a penny.

So, yes they lower friction, and no, not by any amount that's significant in the total picture.

Sixty Fiver

Why would I run knobby tyres on a road bike ?

Why would I spend a crap load of money on something that would not improve my bike's performance by any real world measure or suggest that anyone else does this ?

I work with an ex racer and tourer who has logged at least 500,000 miles in his lifetime and who has been building frames and custom cartridge bearing hubs for 32 years... he will never use ceramics either as he too feels that ceramic bearings in a bicycle are a waste of money.

They are designed for high speed operation (25,000 rpm), require special lubricants, and do not create a magnetic field.

HillRider

Perhaps an even better analogy is to pay refinancing and closing costs to lower your mortgage payments by a penny.

FBinNY 

I like it!. I only referenced the relative benefit, yours covers both the cost and benefit. Consider this stolen.

Nerull

...

Of course an old cruddy steel bearing hub needs to rebuilt to be comparable with new ceramics. And an old cruddy ceramic hub would need to be rebuilt to compare to a new steel hub. This isn't a difficult concept.


And why wouldn't pro teams use whatever they are given? Why do you think team members all ride the same bike, and why isn't everyone riding the latest and greatest bike? The whole point of sponsors giving them kit is so they use it, which works as advertising and gets them money in return. They don't sponsor teams out of the kindness of their hearts. Ceramics don't work any worse over the short term, and teams don't care about the possibility of long term increased race wear (Which may or may not exist) on a part they'll ride once.

Do you really think some tiny fraction of a watt is worth the cost?

On another point - given all the other BS bike companies use to sell things for a lot more money than they're worth, why do you think ceramics are somehow immune? There are lots of expensive carbon stems out there. They're often heavier than the alloy ones, and even the pros won't touch them. But there must be a benefit! Bike companies wouldn't make something solely to profit off of gullible people, would they?

FBinNY 

There's little debate as to whether ceramic bearings are superior to their steel counterparts, but that isn't the right issue.

The issue is whether the benefit realized in a specific application warrants the cost. Take the two main benefits cited.

1- lower friction. You can't save here more than the amount that bearing friction factors into the total energy used to propel a bicycle, and that amount is miniscule, so reducing it by half or even reducing it to zero, would still have no measurable impact on a bicycle operating at anything above 15mph.

2- longer service life. This is a major benefit of ceramic bearings, and in certain applications where replacement is difficult or expensive, would justify their cost. But they are a significant up cost over other quality choices for bicycles, and one could easily replace a number of bearings before spending the same as the initial outlay for ceramics.

So it isn't question of pure superiority, but of cost vs benefit, and that's the argument against ceramic bearings. The benefits are marginal (though real) compared to the cost, and more performance improvement could be had by allocating those added dollars elsewhere on a bike.

kamtsa

This is exactly the Amdahl Law https://en.wikipedia.org/wiki/Amdahl's_law

JohnDThompson 

Yes, it's possible but unless your objective is to gain some bragging rights at the coffee shop, why bother?

badamsjr

[QUOTE=FBinNY;11422014]There's little debate as to whether ceramic bearings are superior to their steel counterparts, but that isn't the right issue.

The issue is whether the benefit realized in a specific application warrants the cost.

So it isn't question of pure superiority, but of cost vs benefit, and that's the argument against ceramic bearings. The benefits are marginal (though real) compared to the cost, and more performance improvement could be had by allocating those added dollars elsewhere on a bike.[/QUOTE

What I hear you saying is that ceramics ARE better than steel, just not enough to warrant their cost?

If that is right, and someone is willing to accept the MARGINAL (though real) gains, and is not concerned with the increased cost, then that person SHOULD consider ceramics?

Personally, I think that once a person has done all the things to maximize the performance and longevity of his bike, and has the chance to squeeze even a LITTLE more out of it, then ceramics become a viable consideration, IF cost is not a determining factor--which seems unlikely if they have already done all they could in trying to get maximums.

In spite of all the opinions out there, there are not many who can cite actual experience with ceramics in bicycle use. Probably the cost issue, or not being willing to try something that 'everyone' KNOWS will not be ANY benefit. In an industry that USED to pride itself on inovation, that is kind of sad. Just my opinion, and obviously not shared by many, but I am not really worried what 'they' will say about it--only how it works for me.

Sixty Fiver

badamsjr - No-one is arguing that ceramic bearings won't improve performance but that the improvement is so small that it is not measurable in the real world.

If I was to install new grade 25 bearings in my bike and use oil lubrication instead of grease I would get a better performance gain than what ceramic bearings would offer as this does reduce resistance and an oiled system flushes out contaminants.

This would cost me less than $5.00.

HillRider

We have had similar threads in the past and badamsjr has hammered repeatedly on his belief that since ceramics are "superior" to steel bearings, they are worth using and, since none of us has actually used them, we have no idea what we are talking about. The actual measurement and testing by other "experts" isn't good enough evidence. As above he has used very poor analogies (like the knobby tire claim) to support his position.

You all have to understand that he has been convinced by the ceramic makers' claims of improvement, has bought into (literally and figuratively) the claims and doesn't want to have his beliefs upset by facts. All of the rational and quantitative data in the world isn't going to convince him.

Sixty Fiver

Mebbe he is in the ceramic bearing business ?

Nerull

It's common behavior for people who get suckered to seek out confirmation from other people who get suckered, and avoid hearing any evidence they got suckered.

He seems to have little understanding of bearing systems - see the rebuild comment - he just has his convictions that he must be right.

It exists everywhere, but I see this a lot in audio. People will spend thousands on "improvements" that aren't even physically possible. Treatments that amount to magic. Platinum-plated power cords and quantum tunneling enhanced digital cables. There is a website charging lots of money for blue food coloring and water in a little bottle that apparently improves sound if you drip it in the right parts of the room.

If you do a blind test, they can't tell their equipment from the cheapest stuff you can buy - there was (maybe still is) a $100000 prize for anyone who could pick out a high end speaker cable vs a lamp cord at a rate better than chance. Never claimed.

But they all pat each other on the back and tell each other how awesome their expensive purchases are.

BikeWise1

Some of you still aren't getting the fact that a purpose built ceramic cartridge bearing is a very controlled environment. Everything is built to the tolerance of the balls. Angular contact cup-and-cone type hubs-even of the highest quality-don't maintain the kinds of tolerances necessary to exploit the difference in grade. And even so, the differences are so small as to be practically impossible to measure.

Even the skateboarders get it:

5. What is the purpose of the higher precision bearings ?
Higher precision bearings are designed to allow high precision machinery to operate smoother and sometimes at higher speeds than a standard bearing would allow. Keeping this in mind, a standard ABEC 1, 608ZZ is rated with a limiting speed of 32,000 RPM with grease lubrication and 38,000 RPM with oil lubrication. The actual speed that the bearing will attain without failure also depends on the loads applied and other running conditions but there is really no need to go into that too heavily here.

We feel that we must stress here that the purpose of higher precision bearings IS NOT TO GO FASTER, but (amongst other things) to ALLOW HIGH SPEED MACHINERY TO OPERATE AT FASTER SPEEDS THAN STANDARD BEARINGS WILL ALLOW. PLEASE ALSO READ POINT 6 BELOW.

6. What will be the result of using these higher grade bearings in Skating Applications ?
The most noticeable result is that you will end up with less money in your wallet and the people that sold you the bearings will be eating out at restaurants at your expense for a few days. Under the following conditions, you may notice an improved performance.

(a) You spend a lot of money (i.e. thousands of dollars) to have your equipment (wheels and board) redesigned and manufactured to suit these high precision bearings. You will need to use some type of shock absorber that allows for absolutely no vibration.

(b) You will have to be prepared to skate on a perfectly smooth surface and make no attempts to use your feet to propel yourself. (Doing so would cause shock loads to the bearings and any extra precision would be lost very quickly).

(c) After you work out how you are going to achieve the above two criteria, you may (and that is only "may") experience a better result than using ABEC 1 bearings after you attain a speed of about 390 KPH (240 MPH) with 65mm wheels and grease lubrication.

From this site.