A comfortable ride is guaranteed, now that Tel Aviv’s SoftWheel has put “selective suspension” inside the wheel. When a wheelchair, bicycle or aircraft encounters an obstacle, he wheel’s hub extends or shrinks symmetrically as needed, dramatically reducing the shock transmitted.
http://www.jpost.com/LandedPages/PrintArticle.aspx?id=341104
http://www.algemeiner.com/2014/02/19/israeli-invention-helps-wheelchair-users-go-down-stairs-video/
http://www.youtube.com/watch?v=tNE4YvxEwc8