A folding tandem bicycle includes a front body part, a rear body part, an intermediate body part connected between the front body part and the rear body part by parallel pairs of upright tubes and pairs of connecting devices, a front transmission mechanism driven by a set of pedals through a front sprocket to rotate a front flywheel and a front wheel through a cable, and a rear transmission mechanism driven by a set of pedals through a rear sprocket to rotate a rear flywheel and a rear wheel through a chain. By disconnecting either one of each pair of connecting devices, the front body part, the intermediate body part and the rear body part are allowed to be folded up and attached with one another side by side. By disconnecting the intermediate body part from the front and rear body parts, the front and rear body parts are connected into a single-seat bicycle for one rider.

A tandem bicycle drive train system includes a continuously variable transmission installed around each crank spindle driving an input crank spindle journalled in a continuously variable transmission unit whose output is connected to a drive sprocket which is journalled between the input crank spindle and the transmission unit. A manual ratio control assembly is suitably mounted to the frame member and positioned around the input crank spindle and suitably coupled with the transmission unit in a manner that provides a smooth, continuously variable change in the input to output rotational speed ratio. Each rider's ratio control is preferably coupled to a manual twist-grip on each rider's handle bar and can be adjusted independent of the other rider's control. The front unit output drives a single sprocket which drives one of two sprockets mounted on the rear unit. A second sprocket on the rear unit drives the rear wheel. Thus, the drive line is at all times a single drive line with two or more variable speed torque inputs from the transmissions around each input crank spindle. Each unit is suitably mounted within an oversize input pedal spindle housing in such manner as to permit sealing from outside contamination.

A foldable bicycle comprises a front frame (1), a rear frame (21), and a seat tube (20). The front frame (1) and the rear frame (21) are foldable with respect to each other. In a first aspect, a single release clamp (12) releases the front frame from the rear frame in a single operation. This occurs by having the seat tube (20) slotted at the top (11). In a second aspect, the crank housing (34) is positioned in axial alignment with the seat tube (20) and one point (14) of folding occur below the crank housing. This aspect pertains to both a men's and a women's frame.

A foldable bicycle frame comprises a front frame made up of a head tube, a top tube and a down tube, and a rear frame made up of a seat tube, a bottom bracket tube, a seat stay and a chain stay. The top tube is provided at the rear end thereof with a connection tube to receive therein a seat post. The bottom bracket tube is provided at the center of the front end thereof with an extension tube which faces the front wheel and is pivoted at the front end thereof to the bottom end of the down tube. The front frame and the rear frame are fastened together by means of the seat post which is inserted into the connection tube and the seat tube. The front frame and the rear frame are rotatable in relation to each other when the seat post is pulled out of the seat tube.

A mechanical release for an electric parking brake has a first cable engaging a housing. A second cable is connected to a lever that is pivotally supported on the housing by a pivot pin. A locking member engages the lever and prevents rotation of the lever when tension is applied to the cables. When the locking member is released, the lever is free to rotate, reducing tension in the cables and freeing the parking brake system.