In an aspect, a tensioner is provided for tensioning a belt and includes first and second tensioner arms having first and second pulleys respectively. The first and second pulleys are configured for engagement with first and second belt spans, and are biased in first and second free arm directions respectively. A second tensioner arm stop is positioned to limit the movement of the second tensioner arm in a direction opposite the second free arm direction. The second tensioner arm stop is positioned such that, in use, the second pulley is engaged with the endless drive member while the second tensioner arm is engaged with the second tensioner arm stop throughout a first selected range of operating conditions.