PURPOSE: To reduce the entire length of a two-wheeled vehicle while still large in a diameter of a wheel, and carry it readily by a trunk of an automobile etc., by a method wherein a sub-frame of the steerable wheel is disposed under a seal element, and a driven wheel is disposed under a steering member, and a connection mechanism is disposed between the steering member and sub-frame.

CONSTITUTION: A seat element 34 is fixed to a support member 33 in an upper part of a free rear end 8' of a curve rear beam 8, and comprises a rear fork 12, namely a sub-frame in the lower part. A carrier 16 of a steering member 17 is rotatably mounted on a shaft pin 15 of a frame part 2. A front end of a push-pull rod 14 is rotatably connected to an arm 18 of the carrier 16. A rear wheel 11 is pivoted by a pivotal of a handle lever, or a front wheel 7 is driven by a pedal mechanism 40. When a fastening screw 35 is unfastened, the seat element 34 is collapsed together with the support member 33. Furthermore, the handle lever is released from a screw mechanism 22 and a steering rod 20 is rotated by a shaft 21.