Tire bead design method

The invention provides a tire seam allowance design method which is used for designing a second seam allowance part, located on one side, close to a steel wire ring, of a seam allowance boundary L0 of a sub-seam in the cross section of a formed tire, and the tire seam allowance design method comprises the steps that the second seam allowance part is sequentially divided into a plurality of areas from outside to inside; calculating the volume V of each area after the tire is formed, obtaining the fitting length L of each area on the forming drum before the tire is formed, and calculating the area S2 of the cross section of each area before the tire is formed according to the formula S2 = V/L; a rectangle with the area equal to the area S2 of the cross section of each area before the tire is formed is designed, the length of the contour line of the side, close to the tire body, of each area after the tire is formed serves as the width b of the corresponding rectangle, the height h of the corresponding rectangle