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Did a ceramic bearing crank the other day.  The bearings are 30grams/44grams lighter per bearing on the H2 and man does it spin SMOOOOOOTH!!

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will thinking about when I will give my cranksghaft to rebuild

What about the bearing with snap ring groove?
Are you able to get that one with ceramics and plastic cage too?

PK

Yes, all of the main bearings for all of the triples are available in ceramic with plastic cages. All of them are also rebuildable.

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There is also the option of plastic cages and steel balls instead of ceramic. A bit less friction from standard steel cages but nothing compared to ceramic. The biggest pitfall with ceramic is $$$$$$

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FYI I am no longer using the RB Tech bearings as I have had to return too many that were not within my specs. No failures to date, but better safe than sorry. Japanese Koyo bearings only They are now included in the rebuild cost.

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Crankshaft Testimonials viewtopic.php?f=25&t=7593

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I have had several questions regarding seal choice lately. Hopefully this will help clarify things a bit.

Lab vs rubber

Both types of seals have pros and cons.

Rubber
Pros:
Plug and play. Just drop it in the case and your done. The cases can have minor imperfections to which the rubber will conform.
In the future should an individual cylinder leak test need to be performed, you can do this with the rubber seals.

Cons:
Rubber can dry out if the engine is left to sit for long periods of time.
Rubber seals wear out over time.


Labyrinth
Pros:
Simply put, they do not wear out.
They do not dry and shrink if left in storage

Cons:
They require a little extra attention when installing. They must be centered so as not to rub on the adjacent bearings.
Loctite 620 may be needed but is not required. It is simply a safeguard.
You cannot do a diagnostic pressure test per cylinder as they will leak when static, however they do seal as well as " new" rubber seals at kicking speed and up.

I would say of the many cranks I have built, it is about 50/50 or so lab/rubber. No issues to date with either. It is personal preference and should be decided considering the above listed information. Also it should be noted that Kawasaki did use labyrinth seals, they were rubber however and were substandard. They switched to the full contact rubber seal in the later years.

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Crankshaft Testimonials viewtopic.php?f=25&t=7593

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Hurley and I used the plastic ball guides, taken from FAG/Norma bearings, as early as 1976. We still had the Japanese steel ball bearings we used them in, not the ceramic ball ones. Those ceramic bearings should be GREAT. We used the same plastic ball guides for more than a few seasons of engine/crank rebuilds, modifications, never had one fail.

ALL our center seals, bypass proprietary pressure activated rubber, contact pressure rubber, and bypass aluminum, are a labyrinth design. Yamaha 250/350/400 twins have used aluminum segmented (labyrinth) center seals for their entire lives, so has all the Yamaha road racing cranks, never a problem. I even built a few seals from scratch on my lathe for various persons, including A7RA's Kawasaki twin crank, and all of my personal cranks. Not hard to pressure/vacuum test an engine with aluminum bypass seals, just have to seal the entire engine, all 3 cylinders up, test all 3 cylinders as one, at the same time. We had to do the original H1 proprietary pressure rubber seal cranks that way.

Poly cage bearings are incredible. Here is a short 17 second video showing the difference. Just for clarification these bearings are for demonstration only. Never a good idea to spin bearings without proper lubrication.
https://youtu.be/AudxLnZbLmk

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Crankshaft Testimonials viewtopic.php?f=25&t=7593

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Just got caught up Keep em coming

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Crankshaft Testimonials viewtopic.php?f=25&t=7593

"Let's keep your crankshaft great!"