Method of making a single rear fork bicycle frame
 A composite legal type bicycle frame is disclosed which contains a front frame portion and a rear frame portion. The front frame portion contains a central main and a plurality of legs for connecting the central main with various components of the bicycle, and the rear frame portion contains a rear fork, which consists of a left rear branch and a right rear branch. The left and right rear branches are first cured and glued together at respective abutting surfaces thereof to form an integral rear fork before they are adjoined with the front frame portion, via prepregs and using a cocuring procedure. The left and right rear branches are formed to contain cross-shaped matching protrusion and recess, respectively, on the abutting surfaces thereof, so as to enhance the integrity of the integral rear fork. As a result, a great flexibility of design options can be obtained. For example, the rear fork can be connected to one of the legs but not to the central main. Also, the front frame portion can be designed such that one of the legs is connected indirectly to the central main via another leg, and not directly connected to the central main. 
Industrial Technology Research Institute of Taiwan
B B B B B
B29C B62K B29C B29C B29L
inventional inventional additional inventional additional
Gou-Don Yu-Hsuan Chin-I Rong-Shian
Chu Chen Lin Liu