A clamping plate 30 is disclose for securing the central disc 24 of a wheel 12 to a wheel flange 14 on an axle 16 of an agricultural vehicle. The flange 14 has a plurality of holes regularly distributed about a pitch circle and the central disc 24 of the wheel and the clamping plate 30 have holes aligned with the holes in the flange 14 for receiving bolts 26 by means of which the central disc 24 of the wheel 12 is clamped between the clamping plate 30 and the flange 14. In the invention, the outer diameter of the clamping plate 30 exceeds the diameter of the pitch circle of the holes in the clamping plate by a distance greater than twice the diameter of the bolts 26.