Abstract: A harvester reel having a shaft is journalled on a supporting frame of a harvesting vehicle for rotation relative to the frame about a main horizontal, transverse axis. A pair of mounting arms are axially spaced apart on and fixed to the shaft, which may be tubular. Extending parallel to the axis and journalled on the two arms is a bat rotatable with respect to the arms for movement about a bat axis parallel to the main axis. At least at one end the bat has a crank carrying a crank pin with a crank axis offset from but parallel to the bat axis. Fixed on the main frame is a circular guide symmetrical about a guide axis eccentric from and parallel to the main axis. A follower, like an eccentric strap, is mounted to rotate on the circular guide. A rod connection to the follower extends to a journal connection on the crank pin.