An adjustable vane system for use with a rotor cage of a threshing system of an agricultural harvester. The vane system includes a vane having a generally helically curved inner profile； a surface being an outer profile that is opposite the inner profile and is generally helically curved over a portion of the vane； a first flat portion proximate an end of the vane on the outer profile； and a second flat portion proximate to another end of the vane on the outer profile.
