An agricultural harvester (10) includes a chassis (12)； a threshing and separating assembly (24) carried by the chassis (12)； and a chopper assembly (72) carried by the chassis (12) that receives crop material from the threshing and separating assembly (24). The chopper assembly (72) includes at least one movable chopping knife (74)； a plurality of counter knives (76) movable between a first knife position and a second knife position, the plurality of counter knives (76) configured to cooperate with the at least one chopping knife (74) to cut crop material when in the first knife position； and a shear bar (78) movable between a first bar position and a second bar position. The agricultural harvester (10) is characterized by a linkage assembly (80, 140) connected to the plurality of counter knives (76) and the shear bar (78) such that the linkage assembly (80, 140) is selectively actuable to simultaneously move the plurality of counter knives (76) between the first knife position and the second knife position and the shear bar (78) between the first bar position and the second bar position.
