Ceramic Bearings Black Bearing: The Black Bearing are hybrid bearings commonly referred to as ceramic bearings. These bearings meet the requirements of cycling (road, MTB, time trial, cyclo-cross...) and are used for wheels, cranksets, derailleur pulleys, and more. Compared to a standard steel bearing, the Black Bearing ceramic hybrid bearings offer numerous advantages: weight savings (the density of ceramic is lower than that of steel), durability at very high speeds, a significantly longer lifespan (multiple times that of a standard bearing), less friction = less loss while pedaling, higher stiffness, greater precision, and better mechanical properties (hardness, compressive strength). The Black Bearing ceramic hybrid bearings consist of the following elements: inner and outer rings made of treated stainless steel for better mechanical strength, balls made of silicon nitride, a steel cage, specific low-friction seals for water and dust protection (2RS), and grease specifically formulated for ceramic bearings.