Abstract: The invention relates to a run-flat tire and rim assembly for all-terrain vehicles (ATV), wherein the rubber thickness of the tire sidewall is at leat 10 times the diameter of the ply cords of a carcass; the height of the radially outermost end of a tire bead apex from the tire bead base is within a range of 20 to 40% of the section height of the tire; each tire bead has a toe with a protrusion protruded radially inwardly from the bead base and a hump groove axially outward of the protrusion; the bead toe comprises a toe strip having a JIS A hardness of 65 to 95; and the rim is provided with a well in the center portion, a pair of bead seats one on each side of the well, a pair of humps one formed axially inward and adjacent to each bead seat to be engaged with the hump grooves of the tire beads and a pair of grooves one formed axially inward of each hump to receive the protrusions of the tire bead toes.