In motorcycle development, weight reduction is important for save resources and reduce environmental impact. On the other hand, it is important to verify the strength and durability of structural materials, such as the frame body, and it is especially important to estimate the loads applied to individual parts when traveling on rough roads at the initial stage of the design. Regarding motorcycle models, a simulation technique for running on rough roads has already been proposed. However, when this simulation technique, as it is, was applied to scooters, a large error occurred in the estimated load values. This was thought to be due to insufficient modeling of the structures and characteristics specific to scooters. Therefore, in this study, in order to develop a simulation model to estimate the loads on the frame body of a scooter, we considered it necessary to obtain these load transmission characteristics and attempted to model them specifically for the scooter. Based on the simulation model for motorcycle type vehicles, components models of the rubber parts, the luggage box including the seat bottom plate, and the cushions were newly built and incorporated into the vehicle simulation model for running when traveling on rough roads. As a result, through the verifications of the estimation errors when loads are applied to individual parts of the frame body when traveling on rough roads, it was confirmed that the vehicle running model for scooters achieved the same level as that for the motorcycles, and the effectiveness of developed modeling technology was confirmed.
