Flat Heavy-Duty Pneumatic Radial Tire and Method of Manufacturing the Same

A method of manufacturing a flat heavy-duty pneumatic radial tire, comprising:

• forming an uncured tire including:
• at least one ply of a carcass layer made of steel cords and multiple plies of steel cord belt layers arranged on the outer periphery of the carcass layer, the steel cord belt layers including at least one ply of a 0-degree belt layer arranged immediately on the carcass layer and made of steel cords having the non-linear stress-strain relationship, and arranged at a cord angle to the circumferential direction of the tire being substantially 0°, and at least two plies of bias belt layers arranged on the outer periphery of the 0-degree belt layer at a cord angle to the circumferential direction of the tire being substantially equal to an equilibrium angle within a range of 45° to 65°;
• curing the uncured tire in a mold;
• removing the resultant cured tire from the mold;
• assembling the cured tire with a rim to be inflated while the tire is in high temperature;
• and
• cooling the cured tire down to normal temperature in a condition of being inflated.