Power transmission incorporating tensioner lever

A power transmission comprising:

• an endless, flexible, traveling transmission medium arranged to transmit rotational power from a driving sprocket to at least one driven sprocket;
• a main tensioner lever in sliding engagement with a part of the length of said transmission medium extending from said driving sprocket to said driven sprocket on the side of said transmission in which the transmission medium moves from the driving sprocket toward said driven sprocket, said lever being elongated along the direction of said length of said transmission medium, having first and second opposite ends, and being pivoted on a pivot axis for movement in a direction to increase tension in said length of said transmission medium;
• and
• an auxiliary lever having an arc-shaped surface in sliding engagement with another part of said length of said transmission medium, said auxiliary lever being attached, and pivotable relative to, said main tensioner lever, adjacent one of said first and second ends of the main tensioner lever.