A roller of an undercarriage track system for a machine is disclosed. The roller includes a body and a sensed feature. The body is a solid of revolution formed about a roller axis. The body includes a bore surface and a roller contact surface. The bore surface defines a bore extending through the body. The bore surface is a radially inner surface of the body. The roller contact surface is located outward from the bore surface. The sensed feature is located at the body. The sensed feature is configured to rotate with the body and to be detectable by a sensor.