A device for transporting a human subject over a surface. The device is a dynamically balancing vehicle having a control loop for providing balance. The device includes a platform defining a fore-aft plane. The platform supports a payload including the human subject. A ground contacting module is included which may include one or more wheels. A ground-contacting member is movably coupled to the platform. The platform and the ground-contacting module form an assembly having a center of gravity that is defined with respect to the ground-contacting member and which includes any loads on the device. The device further includes a support. The support may be a seat for supporting the subject and the support is coupled to the platform in such a manner as to permit variation of the position of the center of gravity in the fore-aft plane by translation and rotation of at least a portion of the support. In one embodiment, translation and rotation of the seat of the device are mechanically coupled together.