A tensioner for an endless drive member, comprising: a base having a proximal end and a distal end and is mountable at the proximal end to a stationary structure; a first tensioner arm that is pivotable relative to the base about a common axis; a first tensioner pulley that is mounted for rotation on the first tensioner arm about a first pulley axis that is spaced from the common axis; a second tensioner arm that is pivotable relative to the base about the common axis; a second tensioner pulley that is mounted for rotation on the second tensioner arm about a second pulley axis that is spaced from the common axis and spaced from the first pulley axis; a tensioner biasing member that is engaged between the first and second tensioner arms (14, 16) to urge the first and second tensioner pulleys (46, 48) towards each other; a first tensioner arm damping arrangement including a first radial damping portion positioned radially between the first tensioner arm and the base, and a first axial damping portion, wherein the first radial damping portion and the first axial damping portion cooperate to provide damping to movement of the first tensioner arm; a second tensioner arm damping arrangement including a second radial damping portion positioned radially between the second tensioner arm and the base and a second axial damping portion, wherein the second radial damping portion and the second axial damping portion cooperate to provide damping to movement of the second tensioner arm; a damping system biasing member (148, 160, 199) that is positioned to apply an axial biasing force to the first and second axial damping portions to generate friction thereat, wherein the first tensioner arm damping arrangement and the second tensioner arm damping arrangement together include a first arm tophat member, and a second arm tophat member, wherein the first and second arm tophat members (144, 146) each include a cylinder that surrounds the base, and a flange, characterized in that the cylinder of each of the first and second arm tophat members (144, 146) has a radially outer surface that is tapered and the inner faces of the first and second tensioner arms (14, 16) are correspondingly tapered so as to mate with the outer surface of the respective cylinder. a base having a proximal end and a distal end and is mountable at the proximal end to a stationary structure; a first tensioner arm that is pivotable relative to the base about a common axis; a first tensioner pulley that is mounted for rotation on the first tensioner arm about a first pulley axis that is spaced from the common axis; a second tensioner arm that is pivotable relative to the base about the common axis; a second tensioner pulley that is mounted for rotation on the second tensioner arm about a second pulley axis that is spaced from the common axis and spaced from the first pulley axis; a tensioner biasing member that is engaged between the first and second tensioner arms (14, 16) to urge the first and second tensioner pulleys (46, 48) towards each other; a first tensioner arm damping arrangement including a first radial damping portion positioned radially between the first tensioner arm and the base, and a first axial damping portion, wherein the first radial damping portion and the first axial damping portion cooperate to provide damping to movement of the first tensioner arm; a second tensioner arm damping arrangement including a second radial damping portion positioned radially between the second tensioner arm and the base and a second axial damping portion, wherein the second radial damping portion and the second axial damping portion cooperate to provide damping to movement of the second tensioner arm; a damping system biasing member (148, 160, 199) that is positioned to apply an axial biasing force to the first and second axial damping portions to generate friction thereat, wherein the first tensioner arm damping arrangement and the second tensioner arm damping arrangement together include a first arm tophat member, and a second arm tophat member, wherein the first and second arm tophat members (144, 146) each include a cylinder that surrounds the base, and a flange, characterized in that the cylinder of each of the first and second arm tophat members (144, 146) has a radially outer surface that is tapered and the inner faces of the first and second tensioner arms (14, 16) are correspondingly tapered so as to mate with the outer surface of the respective cylinder.