Abstract: A rotary component is provided, including a body that has a non-circular periphery and a plurality of teeth positioned about the periphery of the body. The non-circular periphery of the body causes variation in the tension generated in an endless drive member engaged with the rotary component during rotation of the rotary component about an axis. A valley separates each tooth from each adjacent tooth. At least one of the width of each valley and the tooth pitch is generally related to the amount of tension generated in the endless drive member during rotation of the rotary component about the axis at a time when the valley receives a belt tooth. In a preferred embodiment, both the valley width and the tooth pitch are generally related to the amount of tension generated in the endless drive member during rotation of the rotary component about the axis at a time when the valley receives a belt tooth.