We reported in the previous report about a three-dimensional simulation method for the vibration of bogie-track system of railways, and showed that the frictional vibrations of torsional mode are generated in the rail on curved track with 160 m radius. We simulated for the case of 84 m radius with same method, and the torsional vibrations are generated in the rear axle of the bogie in this case. Considering that several modes exist for the frictional vibrations of the system, we made a simplified dynamic model to check the stability of the vibration system for the given slip conditions at the tread. The calculation results for bogies and tracks of two types are in accord with the simulation and measured results.