Pneumatic tire

A pneumatic tire comprising:

• a pair of bead portions each having a bead core disposed therein,
• each of the bead portions having a bead toe, a bead bottom surface, and a flange contacting surface which is an outer surface of the bead portion in a tire axial direction, wherein
• in a pre-mounted state in which the bead portions are held so that a distance in the tire axial direction between the flange contacting surfaces coincides with a rim width of a standard rim,
• each of the bead bottom surfaces is inclined outwardly in a tire radial direction from the bead toe toward the axially outside, and comprises a toe-side portion, a heel-side portion, and a heel-side arc portion,
• the toe-side portion extends axially outwardly from the bead toe at an angle α in a range of from 17 to 24 degrees with respect to the tire axial direction,
• the heel-side portion is positioned axially outside the toe-side portion, and extends axially outwardly at an angle β in a range of from 3 to 7 degrees with respect to the tire axial direction,
• the heel-side arc portion smoothly connects between the heel-side portion and the flange contacting surface with a radius of curvature (R) in a range of from 1.5 to 3.5 mm,
• the toe-side portion and the heel-side portion are connected by a second arc portion arranged between the toe-side portion and the heel-side portion, the second arc portion having an arc shape convex radially outwardly with a radius of curvature in a range of from 3 to 8 mm.