Pneumatic bias tire and manufacturing method for the same

A pneumatic bias tire in which a crown arc part is less likely to be recessed inward and running performance and abrasion resistance are enhanced, and a manufacturing method for the bias tire, are provided. The manufacturing method is for a pneumatic bias tire having a carcass in which at least two carcass plies includes carcass cords that are titled relative to the tire equator by an angle ranging from 20° to 50°, and the carcass cords intersect the carcass cords of the other carcass plies. The manufacturing method includes a green tire forming step of forming a green tire, and a vulcanization step of vulcanizing the green tire. In the vulcanization step, a ground-contact surface Y, on a tire meridian cross-section, of a tread portion 2 is formed so as to have a tread profile 2a including: a crown arc part 10 that forms a crown region TC and projects outward in a tire radial direction with a radius of curvature R1; and shoulder arc parts 11 that form shoulder regions TS, and project outward in the tire radial direction with a radius of curvature R2 greater than the radius of curvature R1.