Abstract: An integral bicycle frame includes a single-piece molded front frame unit with first and second joined regions, and a single-piece molded rear frame unit with upper and lower anchored regions which are respectively coupled with the first and second joined regions through upper and lower coupling joints. Each of the upper and lower coupling joints has a tubular socket blank and a plug blank which respectively have inner and outer tubular surfaces matingly fitted to each other. The inner and outer tubular surfaces of one of the coupling joints are configured to respectively diverge and converge toward each other so as to facilitate inter-engagement therebetween.