A foldable bicycle (1) includes a frame (100) subdivided into two frame halves (144, 145); frame-coupling means (300) intercoupling the two frame haves (144, 145), enabling those two frame halves (144, 145) to pivot relative to each other about a substantially vertical pivotal axis (143); and frame-locking means for locking the frame-coupling means (300) in an unfolded condition of the bicycle (1). According to an important aspect of the present invention, the saddle arm (110) can pivot about a substantially horizontally directed pivotal axis (201), and a forwardly directed pivotal movement of the saddle arm (110) uncouples a locking of the frame-coupling means (300) to permit a pivotal movement of the frame-coupling means (300).

A bike handle tightening device after separated from a bike frame includes a fix tube fixed on a bike frame and having a hollow interior, a vertical rod of a handle, a threaded rod inserting in the vertical rod from top and having a lower end protruding out of the vertical rod, and a tightening member screwing with the threaded rod and having a sloped end surface. The vertical rod and the tightening member are inserted in the fix tube, and the threaded rod is rotated to force the tightening member to move nearer to and contact and rotate along a sloped bottom end surface of the vertical rod so as to let the axis of the vertical rod and the tightening member move away from each other so that the vertical rod and the tightening member push against opposite portions of an inner wall of the fix tube to tighten the handle therein, reducing the size of the bike collapsed for convenience of transporting and storing and helping stabilize the bike after collapsed.

A bicycle includes front and rear wheels, which are mounted respectively on front and rear ends of a bicycle frame. The bicycle frame has an inclined main tube that extends rearwardly and downwardly from a head tube to a seat tube. A drive sprocket is disposed on the main tube, and is located between the head tube and the seat tube. As such, the total length of the bicycle can be shortened.

A folding bicycle comprises a retractable front tube set. Handles at two sides of the top of the front tube set can be folded to the same side. An eccentric rotation device is pivotally provided at the top of the front tube set to drive an internal tube to retract in an outer tube for positioning. A seat tube is pivotally connected with the front tube set. A saddle is provided at the top of the seat tube. A rear tube is pivotally connected with the seat tube. A fastening device is provided between the rear tube and the seat tube to fix the seat tube. The front tube set, the seat tube and the rear tube are connected together by a joint link, which provides the function of a joint to let the front tube set, the seat tube and the rear tube unfold or fold with one another.

A foldable bicycle includes a foldable bicycle frame which comprises a main frame and an enclosing frame foldably to define a receiving cavity; a front and a rear wheel assembly rotatably supported by the bicycle frame; a bicycle driving unit operatively mounted on the bicycle frame and connected to the two wheel assemblies for driving at least one of the wheel assemblies rotating; a steering unit longitudinally extended from the front wheel assembly for steering a moving direction of the front wheel assembly; and a folding arrangement. The folding arrangement includes a folding link connecting the front and the rear wheel assembly, the bicycle driving unit, the steering unit, the enclosing frame, and the main frame in a foldable manner; and a folding actuator operatively connected with the folding link in such a manner that the foldable bicycle is adapted to move between a folded position and an unfolded position.