Abstract: A center pivot irrigation system tower support wheel includes first and second wheel halves, each of the wheel halves including a generally flat circular center hub section and an outwardly extending diverging wheel body section having a conic sidewall section extending at an angle relative to the hub section and an outer ground-engaging generally cylindrical wheel rim connected to the sidewall section and aligned generally perpendicular to the center hub section, the rim including an engagement surface spaced from the connection to the sidewall section. A connection structure is provided for connecting the engagement surfaces of the first and second wheel halves such that the first and second wheel halves form a support wheel having a generally flat circular wheel hub and a wheel body having a generally triangular cross-sectional shape with a generally broad outer surface formed by the generally cylindrical rims.