A detachable bicycle comprises a front frame section including a joint tube at a rear end of the crossbar, a rear frame section including a sleeve extended forward, obliquely from the bottom bracket for receiving a lower portion of the down tube, and a seat tube extended upward from the bottom bracket of the joint tube wherein the seat tube is substantially perpendicular with respect to the down tube, and a seat post inserted through the joint tube and into the seat tube. The seat post and the seat tube are secured to the joint tube by two quick releases. The down tube is also secured to the sleeve by a quick release.