A Steering Arm is the lever projecting from the upright to which the tie rod attaches, converting tie rod travel into rotation of the wheel about its steering axis. Its effective length sets the overall steering ratio for a given rack travel, so a shorter arm produces faster steering and higher steering effort while a longer arm does the opposite. The angle of the arm relative to the vehicle centerline determines the Ackermann characteristic, which is how much more the inside wheel steers than the outside wheel through a turn. Steering arm height also sets the vertical position of the outer tie rod pivot, making it a primary variable in bump steer.