Tire assembly

A pneumatic tire mountable on a rim having a rim diameter RD of not greater than 18 inches, the pneumatic tire comprising:

• a sound damper on an inner surface of the pneumatic tire, the sound damper extending in a tire circumferential direction,
• a ratio SH/SW of a cross-sectional height SH to a tire cross-sectional width SW of the pneumatic tire is 30% to 45%,
• the sound damper includes a sponge material adhered to the inner surface of the pneumatic tire,
• a ratio W/SW of a width W in a tire axial direction of the sponge material to the tire cross-sectional width SW is 10% to 70%,
• the sponge material has a maximum height H in the tire radial direction of not less than 10 mm and not greater than 30 mm,
• the sound damper is centered at center position in the tire axial direction of the inner surface of the pneumatic tire, including at a position on a tire equator C,
• the sponge material has a hardness of 10 to 250 N,
• the sponge material has a tensile strength of not less than 70 kPa, and
• the sponge material has a specific gravity of 0.014 to 0.052.