For subway vehicle that runs through many curve sections, the demand to increase speed at curve sections is increasing. On the other hand, subway lines also have characteristics of small super elevation transition rate at transition curve sections, and wheel load reduction at the transition curve sections should be minimized, especially in an empty condition, since excessive wheel load reduction may cause a derailment of the vehicle. In this paper, the authors examine factors causing wheel load variation such as distortion of vehicle body or bogie. By full vehicle model stand test, the authors have confirmed that distortion of vehicle body would be the most effective factor for a bogie with air suspension.
