The second edition of Bicycling Science includes new information on recent achievements and experiments in human-powered transportation, from the "ultimate human-powered vehicle" (UHPV) in which supine riders can achieve speeds well over 60 mph, to human-powered aircraft, boats, and rail transportation. New chapters cover the history of bicycle and humanpower technology and science, and the speed-power relationships of various modes and vehicles including performance predictions for the UHPV and the "commuter human-powered vehicle." The chapters on braking, steering, friction, air drag, rider cooling, and transmissions and gearing have all been enlarged and updated. James McCullagh, editor of Bicycling Magazine has written a Foreword for this edition which also includes many new illustrations.