Phill P wrote:
HSC make full ceramic bearings as well - but they don't recommend even zirconia races for use on bikes. The shock loads tend to cause the races to crack.
I know a few brands use them for BBs - but the price increase is enormous
Yes, there is that risk. But the way I see it, the BB is suspended between the wheels so won't take much road shock. I'm doing it more as an experiment than anything else. So far so good. However, I would never put full ceramics in a front hub.
I had the HSC full ceramic bearings on my THM BB and they only lasted less than 6 months -- about 700 or so miles. The ceramic races are quite delicate and can easily shatter when you hit a bump while off the saddle. BB started to creak after about 700 miles of the full ceramic install. When I spun the cranks on a stand without the chain, it was obvious that the bearings were toast.
Replaced them with HSC hybrids -- good so far after about 1000 miles.