ABEC Ratings (Annular Bearing Engineer’s Committee) are manufacturing and testing standards that each bearing must pass. These include noise testing at high RPM, precisely defined tolerances for inside and outside bearing diameters, roundness of ball, trueness of races, and the surface finish for all of the above. ABEC ratings are numbered 1 thru 9, odd numbers only, with 9 being the best possible rating. A bearing with a 7 or 9 rating is very difficult and expensive to manufacture, might be perfect for a 40,000 rpm dental hand piece, but is overkill for the slow rotational speeds of bicycle cranks and wheels.Some aspects of ABEC ratings are important for bicycle bearings, but not all. In fact, a high ABEC rating does not mean the bearing spins with less drag, nor does it necessarily equate to high performance, long lasting bearings.  ABEC standards do not account for critical bicycle performance influencers such as load handling capabilities, ball grade and precision, Rockwell hardness, bearing seal quality or lubrication specification. This can lead to confusion in the bicycle marketplace.Visit Enduro Bearing Basics to learn more.