There are basically 3 types of Ceramic Ball Bearings:
HYBRID CERAMIC BALL BEARINGS
Where the rolling element's (balls) are Ceramic but the inner and outer rings are still conventional steels.
PARTIAL CERAMIC BALL BEARINGS
where the rolling elements and the inner ring are Ceramic, but the outer ring is still made of steel.
FULL CERAMIC BALL BEARINGS
Where the rolling element's inner and outer rings are made of silicon nitride.
The advantages of using Ceramic Ball Bearings in your GS / EFE Suzuki Engine and wheels are:
REDUCED ROTATING MASS: The ceramic balls in the bearings are over 60% lighter than their steel counterparts, resulting in faster acceleration and reduced inertial loads.
LOW FRICTION / LESS VIBRATION: The coefficient of friction for the ceramic balls is an average of 3 times lower than steel and the high tolerances for roundness result in dramatically lower vibration levels.
BEARING LIFE / LUBRICANT PRESERVATION: Because of the unique properties of the ceramic balls drastically reduces surface wear when compared to steel balls. This reduction in wear eliminates a large portion of the oil contamination thus prolonging lubricant life.