In a race situation, there's nothing worse than clearing a rough section of trail only to find that your chain has jumped gears or fallen of the chainring entirely when it comes time to accelerate. For XTR M9100, Shimano debuts their own low-profile chain guide that ensures drivetrain stability in these critical moments. Made of a lightweight yet durable resin material, the XTR SM-CD800 Chain Guide holds up to the rigors of aggressive riding without adding significant weight to your bike.