A continuously variable transmission is disclosed for use in rotationally or
linearly
powered machines and vehicles. The single axle transmission provides a simple manual
shifting method for the user. An additional embodiment is disclosed which shifts
automatically dependent upon the rotational speed of the wheel. Further, the practical
commercialization of traction roller transmissions requires improvements in the
reliability, ease of shifting, function and simplicity of the transmission. The
disclosed transmission may be used in vehicles such as automobiles, motorcycles,
and bicycles. The transmission may, for example, be driven by a power transfer
mechanism such as a sprocket, gear, pulley or lever, optionally driving a one way
clutch attached at one end of the main shaft.