Pneumatic tire

A pneumatic tire, comprising:

• a tread portion with an annular shape that extends in a tire circumferential direction;
• a pair of sidewall portions disposed on either side of the tread portion;
• a pair of bead portions disposed toward the inside of the sidewall portions in a tire radial direction;
• a bead core disposed in each one of the pair of bead portions;
• a carcass layer mounted between the pair of bead portions;
• and
• a side reinforcing layer having a crescent-shaped cross-section disposed toward the inside in a tire lateral direction of the carcass layer at each one of the pair of sidewall portions, wherein
• the bead core comprises at least one bead wire wound in the tire circumferential direction,
• in a meridian cross-section, a plurality of circumferential portions of the bead wire form at least one row in line in the tire lateral direction and a plurality of layers layered in the tire radial direction,
• in a meridian cross-section, an external contour shape of the bead core is a polygon formed by common tangent lines of the circumferential portions of the bead wire, the external contour shape comprises a single vertex located toward the outside in the tire radial direction,
• an internal angle formed by two sides sandwiching the vertex is an acute angle, the external contour shape comprises a bottom side located toward the inside in the tire radial direction extending at an incline with respect to the tire lateral direction, and the bottom side forms an angle with respect to the tire lateral direction from 2° to 9°;
• the carcass layer comprises a body portion that extends from the tread portion, through a sidewall portion of the pair of sidewall portions, to a bead portion of the pair of bead portions, and a folded back portion that is bent and folded back along a circumference of the bead core in each one of the bead portions and is extending from a position of an outer end of the bead core in the tire radial direction toward one of the pair of sidewall portions in contact with the body portion;
• a width W1 in the tire lateral direction of an innermost layer of the bead core in the tire radial direction and a maximum width W0 in the tire lateral direction of the bead core satisfy a relationship W1<W0;
• and
• in a meridian cross-section, a tire cross-sectional width T1 along an auxiliary line A1 and a tire cross-sectional width T2 along an auxiliary line A2 satisfy a relationship 0.7≤T1/T2≤1.5,
• where the auxiliary line A1 is an auxiliary line running orthogonal to the carcass layer that passes through an intersection point P1 of a straight line L1 extending parallel with a tire width direction separated from a bead toe 20 mm toward the outside in the tire radial direction and a contour line of an outer surface of the sidewall portion and A2 is an auxiliary line that passes through a center of gravity of the bead core and extends in an inclination direction of the bottom side of the external contour shape.