Thanks for the recommendation Bill. Didn't know you posted until a couple of folks ordering mentioned where they read about the bearings. If anyone has questions regardng ceramic bearings post them here or email & I'll try to help.

Also just posted the info below on another thread which is a little stale, so thought I'd repost it here so those considering ceramic bearings would have more complete info:

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Our little buyer's group has been purchasing ceramic diff/thrust bearings from a manufacturer for about five years now. We have tested eleven of the major brands of ball bearings. I'm posting since what we've found via testing directly contradicts some of the info posted above.

Quality ceramic bearings can perform better (much better) than the best carbide. The problem is that even the very best quality ceramic balls (for our use that would be grade three silicon nitride) can also perform worse -- much much worse -- than carbide. The durability can & does vary radically even when ordering the exact same grade balls.

There is generally very little difference from lot to lot when producing carbide or chrome balls. Ceramic balls are produced in smaller lots & there can be HUGE differences in ceramic balls from one manufacturing lot to the next. All lots are not tested for hardness or durability, in fact generally very few are. This is why R/C racers usually love or hate ceramic bearings. If they get balls from a good batch they are amazingly durable, and if they get balls from a bad batch they can at worst "powderize", which means they disintegrate during use as SRW141 mentions above.

When we asked the manufacturer's response was that a bad batch "is not a rare occurrence". This is consistent with what we found by testing: Seven of the of eleven samples we tested (all were grade 3 SiNi) were more durable than carbide. Four were not, and two of those failed completely (disintegrated) during testing so I'd imagine it is a fairly common occurrence. The only way we've found to insure consistently excellent durability is to buy balls from "certified" lots (where that specific manufacturing run has been tested). The problem is very few ball lots are ever certified since only the USAF, NASA, and a few other buyers require certification (most distributors don't even know what a certified lot is). We need certified balls to race since our little vehicles really put the bearings to the test (especially thrust bearings). NONE of the balls sold for R/C use (by Boca/Acer/IRS/etc) are certified. This is why, even when ordering the best quality, the durability of the bearings varies significantly in R/C. This is also why most experienced racers and all of the pros I know only use ceramic balls from certified lots, or they stick with carbide. And this is why our little buyer's group has been going to the trouble to buy certified balls from the same manufacturer for the past five years or so. We've never had a ball fail & it is simply amazing how long they stay smooth.

We only buy two sizes, as we've found a consistent source for for 3/32 & 5/64 inch size ball bearings (the two we use most in diff & thrust bearings) but there is no consistent source that we been able to find for sealed bearings built exclusively with certified balls. When they are available in the sizes we use they are way up in the stratos in price (around fifteen bucks a bearing) so racers would be better off buying low cost/high quality standard sealed bearings from avidrc.com or rc4less.com.