It is an object of the present invention to reduce a high speed FV n-order
component of a completed tire by specifying a mounting phase of a raw
tire with respect to a vulcanization mold. A variation amount of a total
gage of a tread portion of each of non-vulcanized raw tires Pi (i=1 to m)
each having a plurality of (k) tire constituent members including a joint
portion whose one end and the other end in its circumferential direction
are connected to each other, and a high speed FV of each of completed
tires Qi (i=1 to m) obtained by vulcanizing and forming the raw tire Pi
(i=1 to m) using a vulcanization mold are measured to obtain an
estimation equation. Based on the equation, the mounting phase of the raw
tire after the m-th can be specified.