Abstract: An irrigation wheel for movably supporting an irrigation pipe of a center pivot irrigation system, and including a central hub plate defining a central opening around the wheel axis of rotation. A pair of parallel, spaced annular rim plates of frustoconical configuration extend concentrically around the hub plate and wheel axis of rotation, and are fixed relative to the hub plate by circumferentially spaced spoke rods. The spoke rods are bent at their inner ends so as to define, in their overall configuration, an open space around the center of the wheel and extending out to the rim plates. The rim plates are unconnected to each other, except for the connection afforded by the spoke rods, which extend from the rim plates inwardly to the central hub plate and are connected to the central hub plate. Each rim plate has an inner edge, and has an outer edge which is spaced a greater radial distance from the wheel axis of rotation than is the inner edge.