Topic: CERAMIC TRANSMISSION BEARINGS

[KRONUS0100]

hey guys an gals.  been doing the ebay search thing for 750 trans bearings, have found all of them.  Interesting enuff, most of them are available as cereamic open type ball bearings, the whole thing being made of ceramic polymers.  i then did a google seaarch on these bearings and found they are being used in performance applications.  My question is, for you guys who build the SOHC engines for endurance and racing, would you use these bearings?

i was typing in 6205 open bearing
                      6304 open bearing
                      6305 open bearing
                      6204 open bearing
                      6008 open bearing
                       5206 open bearing
 these appear to be all the bearings in the 750 trans, some are used twice, and all these bearings are available grooved.     so are the ceramics worth the hefty price?    just asking.

[lucky]

hey guys an gals.  been doing the ebay search thing for 750 trans bearings, have found all of them.  Interesting enuff, most of them are available as cereamic open type ball bearings, the whole thing being made of ceramic polymers.  i then did a google seaarch on these bearings and found they are being used in performance applications.  My question is, for you guys who build the SOHC engines for endurance and racing, would you use these bearings?

i was typing in 6205 open bearing
                      6304 open bearing
                      6305 open bearing
                      6204 open bearing
                      6008 open bearing
                       5206 open bearing
 these appear to be all the bearings in the 750 trans, some are used twice, and all these bearings are available grooved.     so are the ceramics worth the hefty pri

I think the question is not can they take the heat but can they take the wear and load without cracking. I would call a bearing company and ask one of the engineers. Matter of fact I think I did one time and they said it was not a good idea. Also I am not sure if they are as round as a steel ball.

From the net...
In the early 1980s, Toyota researched production of an adiabatic engine using ceramic components in the hot gas area. The ceramics would have allowed temperatures of over 3000°F (1650°C). The expected advantages would have lighter materials, no or reduced cooling system, and hence a major weight reduction. The expected increase of fuel efficiency of the engine (caused by the higher temperature, as shown by Carnot's theorem) could not be verified experimentally; it was found that the heat transfer on the hot ceramic cylinder walls is higher than the transfer to a cooler metal wall. Obviously the cooler gas film on the metal surface works as a thermal insulator. Thus, despite all of these desirable properties, such engines have not succeeded in production because of costs for the ceramic components and the limited advantages. (Small imperfections in the ceramic material with its low fracture toughness lead to cracks, which can lead to potentially dangerous equipment failure.)

[MRieck]

Thanks for the research....I appreciate it! I do not know about that Toyota testing BUT the thing that caught my eye was it was done in the 80's.

[KRONUS0100]

ok so its a bad idea in an engine.  the article i briefly read i think was on Volvo.

[MRieck]

ok so its a bad idea in an engine.  the article i briefly read i think was on Volvo.

Woah, woah, woah....it depends on the application. Guys use them all the time in bike engines.

[tweakin]

When I raced road bikes (cycling) all I used was ceramic bearings in all rotating parts.  The parts would roll significantly smoother and longer with less resistance.

Like Mike said, thanks for the research.  Not sure I will put them in my current build but it is a thought.

[MCRider]

Seeing as how its virtually impossible to quantify any advantage in a street bike, consider this. Buy all standard bearings and have them cryogenically treated.

You'll get most if not all the claimed advantages at lower cost and virtually no concern about did i do the right thing, will these fail etc.

At our level its all about parking lot bragging rights. I mean unless you're prepared to run all kinds of sophisticated testing how would you ever know the difference?

[MCRider]

I don't know the price difference. I bought all my bearings from Joe at CBR Bearings.  http://www.cbrbearing.com/ceramic_hybrid_ball_bearings.htm

They are big on ceramics, but i went with standard and cryo.

When I called him and told him I was doing a CB750 trans, he practically rattled off the numbers.

[lucky]

I like the people that have the courage to try new things but sometimes they fail. Just be careful it don't pitch you off the bike at high speed would be my concern.

[754]

 We have a guy here runs them, I think on his wheels (and other places)and he has set a six-pack of records and some pretty impressive speeds at Bonneville.....

[wannabridin]

i read an article where they did the wheel bearings on a 'busa and claimed significant results from less rolling resistance.  my bachelors and masters are in metallurgy and materials science and I've experienced ceramics in loading applications. 

i would say they're fine for newer street bikes or purpose built machines with exacting and tight tolerances, but in a "worn" out 30 year old bike with 30 year old castings, i wouldn't trust them.  the amount of slop, even though minimal, could be enough to cause a stress crack and lead to catastrophic failure.  ceramics do not hold up well to sharp loads, but they're just fine when continuously loaded. 

i would just stick with having the standard bearings (SKF or equivalent) cryo-treated, which will aid in grain refinement and surface hardness.  you will get the best of both worlds here: less rolling resistance and a lot more ductility than ceramic.

just my $.02

[Sam Green Racing]

i read an article where they did the wheel bearings on a 'busa and claimed significant results from less rolling resistance.  my bachelors and masters are in metallurgy and materials science and I've experienced ceramics in loading applications. 

Ceramics do not hold up well to sharp loads, but they're just fine when continuously loaded. 

just my $.02

I agree about the Busa wheel bearings Gee but what do you mean by sharp loads?

Sam.

[lucky]

When I raced road bikes (cycling) all I used was ceramic bearings in all rotating parts.  The parts would roll significantly smoother and longer with less resistance.

Like Mike said, thanks for the research.  Not sure I will put them in my current build but it is a thought.

How did you prove this theory?

[tweakin]

google it....  lots of info.

When I raced road bikes (cycling) all I used was ceramic bearings in all rotating parts.  The parts would roll significantly smoother and longer with less resistance.

Like Mike said, thanks for the research.  Not sure I will put them in my current build but it is a thought.

How did you prove this theory?

[tweakin]

google it....  lots of info if you know what you are looking for.  Remember I was referring to the bicycling industry, I have no experience with ceramics in motorcycles.

When I raced road bikes (cycling) all I used was ceramic bearings in all rotating parts.  The parts would roll significantly smoother and longer with less resistance.

Like Mike said, thanks for the research.  Not sure I will put them in my current build but it is a thought.

How did you prove this theory?

[tweakin]

google it....  lots of info if you know what you are looking for.  Remember I was referring to the bicycling industry, I have no experience with ceramics in motorcycles.  I raced professionally for many years.

When I raced road bikes (cycling) all I used was ceramic bearings in all rotating parts.  The parts would roll significantly smoother and longer with less resistance.

Like Mike said, thanks for the research.  Not sure I will put them in my current build but it is a thought.

How did you prove this theory?

[wannabridin]

Sam,

I meant shock loading, not sharp, oops!!  But if you power shift your trans or something like a harsh downshift, ceramic tends to crack with loads like that.  It has almost no elastic zone (ductility, forgiveness, give) so it tends to fail catastrophically when it does.

I like the cryo route Ron took, and im going to do the same (to damn near everything) when funds allow. 

[MRieck]

We have a guy here runs them, I think on his wheels (and other places)and he has set a six-pack of records and some pretty impressive speeds at Bonneville.....

Correct.

[Retro Rocket]

I researched these a while back and found links to a GSXR forum where there were a few guys using them and they were all happy. I couldn't see a manufacturer making these for any bikes if they were prone tp failure, especially in the litigious environment we live in today. Still considering using them in my bike....

[wannabridin]

Well no company makes something they know has a high likelihood of failure, but incorrect installation or lubrication will cause failure in anything.  That coupled with abuse will wreak havoc on any system.  Another thing to consider is the expansion rates of Al and steel vs ceramic.  Usually these high wear load bearings will have a much lower thermal expansion coefficient, meaning they could possibly become loose as the cases expand with heat and/or wear.  I just don't trust ceramic bearings for a motorcycle.  Yet...  I agree with their potential and KNOW they would help free up a couple of hp in the motor, but I'll let the racers and bigger money spenders have their fun there!

[Sam Green Racing]

Can you get a harder hit on a tranny than when a top fuel bike drops the clutch?

http://www.worldwidebearings.com/motorcycle.htm

Sam.

[wannabridin]

Very good Sam!  But again, those are hybrids.  I'd trust those a lot more, but if they can survive a full clutch drop on something with that much HP, then my bike would be nothing!!

[Tintop]

Can you get a harder hit on a tranny than when a top fuel bike drops the clutch?

http://www.worldwidebearings.com/motorcycle.htm

Sam.

Interesting thread, always something new to be learned here.   It looks from the web site that they only do full ceramics for the wheels, axles, cranks.  Which would make sense, given what wannab has posted re shock load damage.  Looks like hybrids for everything else. 

[Don R]

There is a ceramic bearing thread on dragraceresults.com On the front  of a dragster with ceramic bearings the wheel will continue to spin for 5 minutes. Not sure what grease seal they use. thare was some doubt about the use in a rear axle assembly. The pro stockers are doing it so they surely will take some abuse.
I'd put them in my dragster but funds are already low from some engine issues last season.

[Bill/BentON Racing]

Check out the ones @ microblueracing.com Thinking of using the wheel bearings.Bill