Ceramic Wheel Bearings

I've seen some high end wheels that offer ceramic bearings as an option.  My front wheel bearings showed their "growl" while getting my tire balanced and it is time to replace.  Anybody have any experience with ceramic wheel bearings either pro or con?

The ones I'm looking at are hybrid bearings with stainless steel races, shielded, nylon cage with the hardest, most durable type of ceramic sealed ball bearing silicon nitride (Si3N4, same type used in rocket engines).  These are ABEC-5 rated at electric motor quality at 11,000 rpm which far exceed the 2,200 front wheel rpm our bikes do at top end.  Benefits are they are more durable (4 times more than steel balls), less friction, lower manufacturing tolerances, and more heat tolerant with less thermal expansion.

http://www.vxb.com/p...gs/PROD/Kit8172

Any thoughts, comments, or insights are appreciated.  Thanks...

I thought about it, but it's pretty cost prohibitive, in my opinion. I can't believe you would ever notice any difference in normal usage.
Here's something I noticed when I had my front wheel apart to have powder coated:
Just for fun, I installed the front axle into the forks with the bearings and spacers in their proper positions. What I suppose I kinda knew, but never really thought about is that the only moving parts are the bearing outer races (and ball bearings, of course). Meaning that the inner races are locked in against the outer spacers and inner spacer. The dust seals are locked into the wheel, so they spin against the spacer. Point of my comments? I never greased the dust seal before, but now I do. There is a groove im the inner diameter of the seal, so I smear a bit of grease in there to help reduce friction against the spacer. I think that you would see more benefits in friction reduction from that over the ceramic bearings.

Also, keep your calipers clean. Make sure the pistons are clean and can retract enough to reduce the friction of the pads rubbing on the rotors when the brakes are not engaged. I know Trace suggests that new o-rings aid in this.
By the way, I'm not telling you not to do it. Just that for $140 I don't think you will get any noticeable results and my above suggestions are free. :idea3:

Is that 68 bucks for one or for both?
Regardless, a motorcycle wheel may or may not spin at 2200 RPM at the furthest point in its diameter.  I don't want to do the math or eat pie this early in the morning, but I bet that at the race, it spins MUCH slower.  Even if it did spin at 2200 rpm, I'd still say that it's one of those mods you would do for your own pleasure, knowing full well that there is not going to be any practical gain.

68 bucks each. not cost effective.

Great if you are going superbike racing.

[image: View Post]Rice, on 26 April 2012 - 09:58 AM, said:

Is that 68 bucks for one or for both?
Regardless, a motorcycle wheel may or may not spin at 2200 RPM at the furthest point in its diameter.  I don't want to do the math or eat pie this early in the morning, but I bet that at the race, it spins MUCH slower.  Even if it did spin at 2200 rpm, I'd still say that it's one of those mods you would do for your own pleasure, knowing full well that there is not going to be any practical gain.

Not to be too picky... but RPMs do not take diameter into account. it's Revolutions Per Minute, which is how many times the same point on the wheel passes a fixed point. From the inside of the wheel bearings to the outside of the tire, the RPMs are the same.

That being said, While ceramic sounds cool those are like 5x the price of regular bearings. Can't imagine you get 5x the performance.

[image: View Post]Rice, on 26 April 2012 - 09:58 AM, said:

Regardless, a motorcycle wheel may or may not spin at 2200 RPM at the furthest point in its diameter.  I don't want to do the math or eat pie this early in the morning, but I bet that at the race, it spins MUCH slower.
My thought on this is that the outer race is fixed against the wheel bearing mounting surface of the wheel hub and it rotates without any slippage so it must revolve at the same rate as the outer wheel.  The linear speed is much much slower at the bearing because of the smaller circumference but the rpms are the same.  My quick calcs for 120/70 R17 tire gave 2,277 rpms at 160 mph.  This might not be exact, but I figure it is in the ball park.

Also RE: your previous post, I agree completely about lightly greasing the seals where they meet the spacers, this also should help keep any water out of the bearing area.  And the calipers and rotors will also add friction if not properly maintained and aligned.  I think a poor fork alignment from the previous owners wheel self install caused the bearing failures to begin with and was part of my soft front brake lever feel.

[image: View Post]Veefer800Canuck, on 26 April 2012 - 10:09 AM, said:

68 bucks each. not cost effective.
Great if you are going superbike racing.
I know these are expensive, to be honest, it makes me a little nervous not having good 'ol trusty steel spinning along under me so I started looking top of the line which leads to $$$.  There was an episode of Cafe Racer where one of the Bostrom Bros took a spill because of a bad front wheel bearing that collapsed and locked up the front end.  May have been a result of the builder not properly installing the bearings.

Another benefit I'm hoping for with the ceramic bearings is a smoother front end.  I have a screw holding my right wrist together from a previous injury and it is suseptable to high frequency vibrations that leads to numbness and pain.  As smooth as my VFR is, after a while my hand goes numb and I think it is from some barely perceived vibrations and I'm thinking the ceramic bearings may be a little smoother.

[image: View Post]Rush2112, on 26 April 2012 - 10:39 AM, said:

[image: View Post]Rice, on 26 April 2012 - 09:58 AM, said:

Regardless, a motorcycle wheel may or may not spin at 2200 RPM at the furthest point in its diameter.  I don't want to do the math or eat pie this early in the morning, but I bet that at the race, it spins MUCH slower.
My thought on this is that the outer race is fixed against the wheel bearing mounting surface of the wheel hub and it rotates without any slippage so it must revolve at the same rate as the outer wheel.  The linear speed is much much slower at the bearing because of the smaller circumference but the rpms are the same.  My quick calcs for 120/70 R17 tire gave 2,277 rpms at 160 mph.  This might not be exact, but I figure it is in the ball park.

Also RE: your previous post, I agree completely about lightly greasing the seals where they meet the spacers, this also should help keep any water out of the bearing area.  And the calipers and rotors will also add friction if not properly maintained aligned.  I think a poor fork alignment from the previous owners wheel self install caused the bearing failures to begin with and was part of my soft front brake lever feel.

[image: View Post]Veefer800Canuck, on 26 April 2012 - 10:09 AM, said:

68 bucks each. not cost effective.
Great if you are going superbike racing.
I know these are expensive, to be honest, it makes me a little nervous not having good 'ol trusty steel spinning along under me so I started looking top of the line which leads to $$$.  There was an episode of Cafe Racer where one of the Bostrom Bros took a spill because of a bad front wheel bearing that collapsed and locked up the front end.  May have been a result of the builder not properly installing the bearings.

Another benefit I'm hoping for with the ceramic bearings is a smoother front end.  I have a screw holding my right wrist together from a previous injury and it is suseptable to high frequency vibrations that leads to numbness and pain.  As smooth as my VFR is, after a while my hand goes numb and I think it is from some barely perceived vibrations and I'm thinking the ceramic bearings may be a little smoother.
I don't know if you have them, but an excellent cure/abatement of handlebar vibration are these: http://www.vibranato...01-t150-brt.htm . I was skeptical but decided to try them, and believe me they really do work. And they're cheaper than the ceramic bearings, which I think are waaaaay overkill.

Buy them. $140 is not much for peace of mind. They make as much sense as many of the non-performance farkles I read about. Overkill? It's all overkill. Just check out the supercharger thread. And, who knows, there may be a performance improvement.

When we spend $ on motorcycles, Since when does it have to make any Sense how we spent our Cents?

My Bonneville bike has ceramic wheel bearings.  I didn't notice a change in either smoothness or rolling resistance, although I didn't expect very much.  I did it to try and gain any advantage possible.  I did see a significant difference in engine performance when I rebuilt the motor with ceramic bearing, but the rpms are a lot higher.

If you do use them, and if the $ isn't a huge issue I say go for it, make sure you freeze the bearing and get a heat gun on the wheel.  They'll drop right in, and pressing the bearing in can (I've been told) crack the ceramic balls.

Personally I don't see how ceramic bearings are going to give one peace of mind. If I wanted peace of mind I would stick with steel. Ceramic will give a certain of amount of whiz-bang though.

Whiz-bang is what we're all about.

[image: View Post]FJ12Ryder, on 26 April 2012 - 11:27 AM, said:

I don't know if you have them, but an excellent cure/abatement of handlebar vibration are these: http://www.vibranato...01-t150-brt.htm . I was skeptical but decided to try them, and believe me they really do work. And they're cheaper than the ceramic bearings, which I think are waaaaay overkill.
I glad to hear the Vibranators work for you.  I was looking at those too.  My only concerns I have is that I would lose my throttlemeister cruise control and that the Vibranators work on a tuned mass dampening principle.  This implies that the mass used is tuned to a specific frequency and I'm afraid that would be designed more for lower engine frequencies to reduce arm pump and not so much for the higher frequencies.

From your experience do you have any input on the frequencies the Vibranators dampen?

[image: View Post]mk2davis, on 26 April 2012 - 11:50 AM, said:

My Bonneville bike has ceramic wheel bearings.  I didn't notice a change in either smoothness or rolling resistance, although I didn't expect very much.  I did it to try and gain any advantage possible.  I did see a significant difference in engine performance when I rebuilt the motor with ceramic bearing, but the rpms are a lot higher.

If you do use them, and if the $ isn't a huge issue I say go for it, make sure you freeze the bearing and get a heat gun on the wheel.  They'll drop right in, and pressing the bearing in can (I've been told) crack the ceramic balls.
Thanks for the feedback on your experience with ceramic bearings.  I have to admit, I'm a little disappointed you didn't see an improvement in smoothness.  Your comments on freezing the bearings for install are spot on and that was my first thought when Bostrom crashed on the  Cafe Racer show..."builder didn't freeze the bearings and beat them in instead causing bearing failure".

I don't have a heat gun, how much heat should be introduced to the hub?  Are we talking blow dryer or blow torch?  Those I have...

[image: View Post]Rush2112, on 26 April 2012 - 12:44 PM, said:

[image: View Post]FJ12Ryder, on 26 April 2012 - 11:27 AM, said:

I don't know if you have them, but an excellent cure/abatement of handlebar vibration are these: http://www.vibranato...01-t150-brt.htm . I was skeptical but decided to try them, and believe me they really do work. And they're cheaper than the ceramic bearings, which I think are waaaaay overkill.
I glad to hear the Vibranators work for you.  I was looking at those too.  My only concerns I have is that I would lose my throttlemeister cruise control and that the Vibranators work on a tuned mass dampening principle.  This implies that the mass used is tuned to a specific frequency and I'm afraid that would be designed more for lower engine frequencies to reduce arm pump and not so much for the higher frequencies.

From your experience do you have any input on the frequencies the Vibranators dampen?
My experience, just seat-of-the-pants mind you, is that they ameliorate the lower frequency vibrations more than the high.  My opinion anyway.

[image: View Post]MaxSwell, on 26 April 2012 - 12:01 PM, said:

Whiz-bang is what we're all about.
Good point, as I just spent $50 on a silly rear wheel plug. :smile:

[image: View Post]Rush2112, on 26 April 2012 - 09:34 AM, said:

I've seen some high end wheels that offer ceramic bearings as an option.  My front wheel bearings showed their "growl" while getting my tire balanced and it is time to replace.  Anybody have any experience with ceramic wheel bearings either pro or con?

It would seem to me that ceramic bearings would be prone to fail catastrophically and without warning.   But a steel bearing will always (in my experience) announce their failure long before it arrives, thus the growling you're experiencing.

True?   Untrue?  I've never read a bit of literature on ceramic bearings.

[image: View Post]Lee 2002, on 26 April 2012 - 05:22 PM, said:

[image: View Post]Rush2112, on 26 April 2012 - 09:34 AM, said:

I've seen some high end wheels that offer ceramic bearings as an option.  My front wheel bearings showed their "growl" while getting my tire balanced and it is time to replace.  Anybody have any experience with ceramic wheel bearings either pro or con?

It would seem to me that ceramic bearings would be prone to fail catastrophically and without warning.   But a steel bearing will always (in my experience) announce their failure long before it arrives, thus the growling you're experiencing.

True?   Untrue?  I've never read a bit of literature on ceramic bearings.
Did a little bit more research and here is some literature:

"Silicon nitride bearings are both full ceramic bearings and ceramic hybrid bearings with balls in ceramics and races in steel. Silicon nitride ceramics have good shock resistance compared to other ceramics. Therefore, ball bearings made of silicon nitride ceramic are used in performance bearings. A representative example is use of silicon nitride bearings in the main engines of the NASA's Space Shuttle.[21][22]

...from the Oak Ridge National Laboratory:
Silicon nitride ball bearings are harder than metal which reduces contact with the bearing track. This results in 80% less friction, 3 to 10 times longer lifetime, 80% higher speed, 60% less weight, the ability to operate with lubrication starvation, higher corrosion resistance and higher operation temperature, as compared to traditional metal bearings."

I though that these bearing were made and used to reduce weight.

[image: View Post]mk2davis, on 26 April 2012 - 11:50 AM, said:

and pressing the bearing in can (I've been told) crack the ceramic balls.

[image: View Post]Rush2112, on 26 April 2012 - 12:50 PM, said:

"builder didn't freeze the bearings and beat them in instead causing bearing failure".
Two examples of how improper installation procedures may cause premature failure. When the balls are under pressure while installing the wheel bearings, they put presure on the wrong race. Beating the bearing into it's (aluminum) seat can easily damage the seat.

I haven't used hybrids on the VFR but I have them (Si3N4) installed in my mountainbike. Yes they last a lot longer than regular bearings and when dirt does get past the seals it doesn't immediately ruin the bearings. They offer hardly any reduced friction as it seems most of the friction comes from the seals. I too always put some grease behind the the dust seals of the VFR front wheel, not to reduce friction but to keep them in a good shape for a longer period.

The stock bearings are life time items, if everytime you take the wheel off, you take some gear oil and try to work into the bearings(a tad will get in and thats all you need), greasing the seals and axle is also recommended.

[image: View Post]timmythecop, on 27 April 2012 - 03:02 AM, said:

I though that these bearing were made and used to reduce weight.
They'll definitely be lighter, but it looks like they will offer some other benefits too(less friction, harder, longer life).  The more I learn the more confidence I've gained in them.  I took the plunge and bought a set, they are scheduled to be delivered 5/7.  I'll weigh them and compare to the Honda OEM bearings.  I'm still using the stock VFR wheel so it won't make a huge dent in the weight... but maybe they'll smooth things out... you never know till you try!