To improve the riding comfort of railway vehicles, it is important to reduce the bending vibration of carbody. The bending vibration is sometimes caused by way of the connecting elements between carbody and truck, such as bolster anchors, single link type traction devices and yaw dampers. This report describes a new mathematical model to investigate the riding comfort of railway vehicles in which the effects of these connecting elements are taken into account. The riding comfort level L_T is used to evaluate the quality of riding comfort. And numerical studies are carried out to investigate the effects on the L_T of the specification parameters of bolster anchors, single link type traction devices and yaw dampers.