A vehicular external rearview mirror system comprises a twin-arm assembly comprising a pair of parallel support arms connected at one end to a base attached to the vehicle and movably connected at another end to a reflective element assembly through a movable support bracket. The support bracket supports a reflective element assembly and is attached to the twin-arm assembly through a pair of integral bearings which translate along the arms to extend or retract the reflective element assembly. In one embodiment, the bearing imparts a friction force to the arm to enable the bracket to be moved along the arm under the influence of an extension/retraction force, but to maintain the bracket at a selected position along the arm when the force is removed. In another embodiment, the bearing is adapted for frictionless translation of the bracket along the arms under the influence of a powerextend actuator. In yet another embodiment, the bearing is integrated into the movable support bracket for frictional support of the bracket on the arms.