This paper considers personal mobility vehicles with lean mechanism. We performed a sensitivity analysis of the influence of change in vehicle parameters, such as height of center of gravity and steer characteristics, on the rollover limit. To achieve this, a simulation analysis using a multi-degree-of-freedom vehicle dynamics model was performed. The results of the simulation analysis showed the relationship between the dynamic response of roll motion with lean mechanism from a maneuvering input and the rollover limit characteristic, including a phase delay.