Abstract: A bicycle and frame are disclosed, including a unitary front frame and a rear frame. The front frame includes a down tube rigidly connected to a head tube, a steerable front wheel assembly, and a crossbar rigidly fixed to one or both of the head tube and the down tube. The down tube is connected to the rear frame at a pivot proximate the bottom bracket shell. The rear frame includes a seat tube, a bottom bracket shell and a chainstay, all rigidly connected at the bottom bracket shell. A frame lock is disposed at the rearward end of the crossbar, for locking to the rear frame to substantially immobilize the pivot, placing the frame in a riding condition. The frame lock, when disengaged, facilitates relative movement of the front frame and the rear frame towards each other about the pivot, in a common vertical plane, to place the frame in a collapsed position, such that the down tube lies alongside the seat tube and the front frame and the rear frame are nested.

Abstract: A bicycle and frame is disclosed including a rear frame structure including a seat tube, a bottom bracket shell and a chainstay terminating in a rear wheel mount. A forward end of the chainstay, a lower end of the seat tube, and the bottom bracket shell are rigidly connected. A front frame structure includes a down tube rigidly connected to a forwardly disposed head tube and connected to the rear frame at a pivot proximate the bottom bracket shell facilitating pivoting of the front frame with respect to the rear frame in a common vertical plane. A frame lock when engaged substantially immobilizes the pivot to place the frame in a riding condition and when disengaged facilitates relative movement of the down tube and the seat tube towards each other about the pivot in the common vertical plane to place the frame in a collapsed condition such that the down tube lies alongside the seat tube.