Originally Posted by csown

Hi guys,

My powertap just went crunchy and I'll need to replace 4 6901 bearings. I'm considering my options and am wondering about the real-world longevity of various types of ceramics and would like to know peoples' experiences with them.

So I know all the stuff about how ceramic bearings don't actually save you much in frictional losses for loaded wheels. What's important to me here is longevity - I really don't want to have to go back in and replace the bearings every 3K miles. I'm also a cheapskate so I really want to do this under about $75, and under $50 ideally. I'd be happy if it doubled the longevity of a good quality all-stainless bearing.

So I was looking at the hybrid bearing type like the $10 ceramic w/ stainless cage from VXB. It's an ABEC-5 and I'm guessing the balls are probably ceramic-coated stainless given their vague description and the fact that they sell another ABEC-5 bearing with Silicon Nitride balls for 50% more. It looks like it might be a good compromise between a good quality stainless at $5 a pop and a full ceramic at $60.

Anyone have problems with the ceramic coating grinding off and wrecking the bearings? Also, any experiences with how these do in the wet?

Thanks!