A towed agricultural implement includes one or more processing units each supported on a chassis, in which each chassis supports at least one processing unit on a central axis, the chassis having a left hand side wheel assembly support and a right hand side wheel assembly support, free ends of the wheel assembly supports having wheel assemblies, each wheel assembly comprising a wheel mounted on a wheel mount, the wheel mount being rotatable about an inclined axis, and the wheel being rotatable about a horizontal axis. The wheel assembly supporting structures and the wheel mounts allow limited relative movement of each wheel mount with respect to the wheel assembly supporting structures which enables greater control when the towed agricultural implement is towed about a corner.