Few studies have investigated the vibration characteristics of motorcycle tires. Tires have high damping characteristics; therefore, resonance peaks do not appear clearly, and it is difficult to identify the existence of modes in a high-frequency region having many modes. A similar phenomenon occurs in automobile tires; therefore, the circumferential mode reduction method is used to reduce the number of degrees of freedom of the frequency response function. This method is specialized for periodic shell structures under the assumption that the circumferential mode shape can be represented by trigonometric functions. However, the applicability of this method to the experimental modal analysis of motorcycle tires with a double curvature remains unclear. Therefore, in this study, we verify whether this method can be applied to periodic shell structures with a double curvature. Next, we try to understand the modal characteristics of motorcycle tires. Finally, we compare the identified modal characteristics with those of automobile tires.