5x13x4mm Precision Ceramic Ball Bearings Hybrid Seals Yellow (2)

These bearings don't exactly spin better and faster than plain Steel bearings. I spun them up in a drill before installing to check function and they were very stiff. Felt like plain Steel bearings. much drag when spinning. From my experience, Ceramics should not come lubed very heavily as these probably are???? By comparison, I have Boca Bearing Ceramics and they spin out the box very smooth and fast, no break in needed. I just may take them apart to see if they are in fact Ceramic balls and remove grease if they have too much, I may clean out and use a drop of oil ...no grease. Hope this helps others considering these Ceramics. BTW, I dont feel Ceramics should last any longer than Steel BB's. Its the performance gain that matters with cermaic BB's. I dont think these cut it in this regard. These are Motor bearings for my Arrma 1/8 2050 KV motor. FWIW.