3 ms·Trevor built a one-wheel Segway once. It was quite difficult to ride.by pg 16y agoTrevor built a one-wheel Segway once. It was quite difficult to ride.s-phi-nl 16y agoLink to description: http://trevorblackwell.com/eunicycle.html http://trevorblackwell.com/eunicycle.htmlpg 16y agoHe also built another one that didn't have a seat, and that you balanced on with your feet.