A bead guide includes a columnar portion having a cylindrical side surface, and a guide plate extending from a distal end of the columnar portion. Through rotation of the bead guide, an expansion bar rotation driving section selectively switches the bead guide between a first position at which the guide plate is retreated radially inwardly from an outer circumferential end of a wheel, and a second position at which at least a part of the guide plate protrudes radially outwardly from the outer circumferential end of the wheel. The bead guide is switched from the first position to the second position so that the guide plate is caused to enter below an upper bead.