Because of theoretical benefits, such as a tighter turning radius at low speed, attempts have been made to construct motorcycles with two-wheel steering. One working prototype by Ian Drysdale in Australia is reported to "work very well."[47][48] Issues in the design include whether to provide active control of the rear wheel or let it swing freely. In the case of active control, the control algorithm needs to decide between steering with or in the opposite direction of the front wheel, when, and how much. One implementation of two-wheel steering, the Sideways bike, lets the rider control the steering of both wheels directly. Another, the Swing Bike, had the second steering axis in front of the seat so that it could also be controlled by the handlebars. Milton W. Raymond built a long low two-wheel steering bicycle, called "X-2", with various steering mechanisms to control the two wheels independently. Steering motions included "balance", in which both wheels move together to steer the tire contacts under the center of mass; and "true circle", in which the wheels steer equally in opposite directions and thus steering the bicycle without substantially changing the lateral position of the tire contacts relative to the center of mass. X-2 was also able to go "crabwise" with the wheels parallel but out of line with the frame, for instance with the front wheel near the roadway center line and rear wheel near the curb. "Balance" steering allowed easy balancing despite long wheelbase and low center of mass, but no self-balancing ("no hands") configuration was discovered. True circle, as expected, was essentially impossible to balance, as steering does not correct for misalignment of the tire patch and center of mass. Crabwise cycling at angles tested up to about 45° did not show a tendency to fall over, even under braking.[citation needed] X-2 is mentioned in passing in Whitt and Wilson's Bicycling Sc

ence 2nd edition. The sideways bike is an invention, patented in 2005,[1] by Michael Killian, a software engineer from Dublin. He was inspired by the way that snowboarding is preferred to skiing due to the greater artistic potential, and decided to design a snowboard equivalent for the conventional bicycle. The result: a bike ridden sideways with the rider operating both wheels. The bike, unlike a conventional bike, uses front-to-back balance like a snowboard. Conventional bikes use left-to-right balance, like skis. The sideways bike is different in many ways from a conventional diamond-framed bicycle. The rider controls direction by steering with both front and back handlebars. This means that the bicycle can maneuver effectively in congested conditions, weaving in and out of cars and performing tight turns. It also means that the rider can move the bike sideways, as the name suggests, such that the movement is perpendicular to the direction in which the frame points. Although this is possible, it is very difficult, as it is necessary for the rider to have extremely good balance and coordination. The position of the pedals and cranks varies from bike to bike. Some sideways bicycles have them positioned in the same way that a normal bike does; however, there are some that are placed such that the rider must sit not facing in the direction of movement but perpendicular to it. This means that turning is easier and more elegant; however, visibility is impaired as the rider must turn his or her neck all the time. Sideways bikes are single speed, which means that gears have not yet been worked into the complex design of transmission of power from the cranks to the back wheel. Since it pivots, a normal chain system cannot function, but Killian created a part that allows the rear cassette to cause the wheel to rotate even when turning, by having an intermediate piece that can transmit the power.