| 摘要 |
A bicycle having a frame with a strengthened structure, the bicycle comprising: a front wheel (11), a back wheel (12), a frame (30), two pedals (80), a brake mechanism (50), a cushion (40) and a front bicycle portion (20). The front bicycle portion (20) comprises an upper handlebar (21), a front fork (22) connected to a lower end of the handlebar (21), and a head tube (23) covering an upper end of the front fork (22). A bottom portion of the front fork (22) is connected to the front wheel (11). The frame (30) comprises an upper tube (31), a lower tube (32), an upright tube (33) and a back fork (34). A front end of the upper tube (31) is connected to an upper end of the head tube (23) and extends backward from the head tube (23), and a back end of the upper tube (31) is connected to the upright tube (33). The upright tube (33) has an approximate "V" shape, and a lower end of the upright tube (33) is connected to the back fork (34). The back fork (34) extends backward from the lower end of the upright tube (33). The lower tube (32) is located below the upper tube (31), and extends from a middle bending position of the upright tube (33) to a lower end of the head tube (23), and connects the head tube (23) to the upright tube (33). Two sides of back ends of the back fork (34) are connected to the back wheel (12). A funnel-shaped downward recessed portion (311) is formed from a middle portion of the upper tube (31). The front end of the upper tube (31) is formed with an upper convex portion (312). The upper convex portion (312) extends backward and gradually reduces in size to have an elongated bar shape, and extends to the downward recessed portion (311), thus increasing an overall strength of the frame (30). |
