A bicycle chain guide assembly that includes a mounting bracket adapted to be affixed to a bicycle, and a movable member movably mounted to the mounting bracket. The movable member includes a chain guide portion adapted to be positioned adjacent a chain ring of the bicycle and below a bottom bracket of the bicycle. When the assembly is mounted on a bicycle with a chain-ring, the movable member can move in a first direction such that the chain guide portion moves toward an outer circumference of the chain-ring and the movable member can move in a second direction such that the chain guide portion moves away from the outer circumference of the chain ring.