A clutch means includes an immobile tube (60) disposed between a top tube (2) and a head tube (6) of a bicycle frame, with a bearing portion (20) mounted to one of the facing end portions and axially supporting the end portions, whereby the top tube (2) and the immobile tube (60) are disposed so as to be capable of relative rotation. In the outer periphery of the bearing portion (20) and the immobile tube (60) axially supported therein, pin holes (22, 62) are respectively opened. The pin holes (22, 62) are bored at positions that are centrally aligned when a front fork (4) of the bicycle is are linearly positioned.

A clutch means includes an immobile tube (60) disposed between a top tube (2) and a head tube (6) of a bicycle frame, with a bearing portion (20) mounted to one of the facing end portions and axially supporting the end portions, whereby the top tube (2) and the immobile tube (60) are disposed so as to be capable of relative rotation. In the outer periphery of the bearing portion (20) and the immobile tube (60) axially supported therein, pin holes (22, 62) are respectively opened. The pin holes (22, 62) are bored at positions that are centrally aligned when a front fork (4) of the bicycle is are linearly positioned.

A convertible bicycle has separable front and rear wheel units. The convertible bicycle can operate in individual or in tandem mode as a tricycle unit. The rear wheel unit has a vertical interlocking gear which can interface with a frontal interlocking gear of the frontal wheel unit. The front wheel unit of an auxiliary bicycle can be detached and the remaining rear wheel unit attached to the rear wheel unit of another bicycle in order to form a tandem tricycle.

One embodiment of a compact front wheel drive cycle in which the front steerable fork is connected to the frame via a spring. And in addition, the rear fork is attached to the frame via a freely rotating caster pivot. Other embodiments are described and shown.

A water bike apparatus powered by at least human energy or a motor and comprising motion-inducing flotation elements with steering elements and with no stationary flotation elements necessary for flotation of the apparatus.

A kit for an electric cycle includes a powertrain module including a case, a battery disposed in the case, an electric motor in communication with the battery and disposed in the case, and a connecting port on the case. The kit includes a first module including a frame member configured to releasably engage the connecting port and a wheel rotatably connected to the frame member, a second module including a frame member configured to releasably engage the connecting port, and a releasable locking feature on the connecting port.

A kit for an electric cycle includes a powertrain module including a case, a battery disposed in the case, an electric motor in communication with the battery and disposed in the case, and a connecting port on the case. The kit includes a first module including a frame member configured to releasably engage the connecting port and a wheel rotatably connected to the frame member, a second module including a frame member configured to releasably engage the connecting port, and a releasable locking feature on the connecting port.

A kit for an electric cycle includes a powertrain module including a case, a battery disposed in the case, an electric motor in communication with the battery and disposed in the case, and a connecting port on the case. The kit includes a first module including a frame member configured to releasably engage the connecting port and a wheel rotatably connected to the frame member, a second module including a frame member configured to releasably engage the connecting port, and a releasable locking feature on the connecting port.

A kit for an electric cycle includes a powertrain module including a case, a battery disposed in the case, an electric motor in communication with the battery and disposed in the case, and a connecting port on the case. The kit includes a first module including a frame member configured to releasably engage the connecting port and a wheel rotatably connected to the frame member, a second module including a frame member configured to releasably engage the connecting port, and a releasable locking feature on the connecting port.

A tandem rider device and method of use for maintaining three planes of stability, elimination of interference and steering is presented. In particular, the present invention relates to devices and mechanisms, which when connected to the three planes of stability, vertical, horizontal and axial, between two duplicate personal transportation devices or between the transportation device and another device including structural stability elements provide for the following three enhancements. Provide tracking wheels, levers, springs and pedals for interference elimination devices allowing removal of tracking wheel interferences when two devices are connected together. Providing steering mechanism used for steering two duplicate personal transportation devices or steering the transportation device and another device when the tandem rider device is placed on a suitable surface other than parallel tracks. Providing a plurality of assemblies, that when such assemblies are removed, allow engagement of the steering mechanism when the transportation devices are removed from parallel tracks.