Pneumatic tire having bead core with stretchable portion

A pneumatic tire comprising a pair of ring-shaped beads and a carcass extending on and between one of the beads and the other bead,

• wherein
• each bead includes a core and an apex extending from the core outward in a radial direction,
• each core includes:
• a main body including a cord extending in a circumferential direction;
• and a stretchable portion formed from a crosslinked rubber,
• the stretchable portion is located inward of the main body in an axial direction, and
• the stretchable portion has a size with which at least one cross-section of the cord can be included therein in a cross-section of the bead;
• and
• wherein
• each main body includes a hard unit and a soft unit,
• the soft unit is located outward of the hard unit in the radial direction,
• the hard unit includes a hard cord extending in the circumferential direction,
• the soft unit includes a soft cord extending in the circumferential direction,
• the soft cord stretches more easily than the hard cord, and
• the stretchable portion has a size with which at least one cross-section of the hard cord can be included therein in the cross-section of the bead;
• and
• further wherein
• each main body further includes a middle unit,
• the middle unit is located outward of the hard unit in the radial direction and located outward of the soft unit in the axial direction,
• the middle unit includes a middle cord extending in the circumferential direction,
• the middle cord stretches more easily than the hard cord,
• the soft cord stretches more easily than the middle cord, and
• in a cross-section of the main body,
• one cross-section of the middle cord is located outward of one cross-section of the hard cord in the radial direction and inward of the one cross-section of the hard cord in the axial direction, and
• one cross-section of the soft cord is located outward of the one cross-section of the middle cord in the radial direction and inward of the one cross-section of the middle cord in the axial direction.