Based on the automatic steering system that is controlled by changing center of body weight. As it is much stable than two-wheel drive bicycle, it can be easily used by the old and weak persons, women and girls who couldn't learn to ride bicycle because of fear. <br />Moreover, as it can be powered by hand and/or feet, the partially disabled person on hand or foot can enjoy it. <br />http://www.skywheel.kr/board/read.php?np=1&pid=69952&uid=988080
