Bicycle belt or chain drive tensioning systems and IGH-thru-axle conversion systems are described that includes first and second anti-rotation keys, a bushing, and first and second fasteners configured to center the IGH laterally within first and second dropouts of the bicycle. The belt or chain tensioning device includes a mounting clamp, a swing arm assembly with a stepped pivot shaft, a swing arm, a first pulley rotatably supported by the pivoted shaft, and a second pulley rotatably attached to the swing arm, the first pulley and the swing arm rotating about a longitudinal axis of the stepped pivot shaft. Methods for assembly and operation of such systems are also disclosed.