A lower spoke cored bar of a spoke cored bar constituting a spoke portion couples one end portion of a first coupling portion to a rim cored bar. The lower spoke cored bar couples one end portion of a second coupling portion to a boss cored bar. The lower spoke cored bar is provided with a vertical wall portion which couples a bending-shaped first bent portion to the other end portion of the first coupling portion, and which couples a second bent portion in a bending form to the other end portion of the second coupling portion. The rim cored bar is provided with a deformation allowing portion capable of deforming. The vertical wall portion and deformation allowing portions are arranged substantially on the same line.