BMW uses a new tetrahedrally amorphous carbon (ta-C) coating material for the rollers. It is also known as industrial diamond.
This coating is harder and more resistant than Diamond Like Carbon. The only thing tougher is pure diamond.
BMW says the ta-C industrial diamond coating “does not wear off” and “drastically” reduces the friction coefficient.
“Thanks to excellent dry lubrication properties and the elimination of wear, the tetrahedral amorphous carbon coated rollers of the M Endurance chain offer maintenance comfort equivalent to that of a shaft drive motorcycle,” BMW claims.
“This includes all the cleaning work that is unavoidable with a conventional chain due to splashed lubricant. Accordingly, the M Endurance chain also offers maximum environmental friendliness.”