Patent ID: 7390005

Claim:
A tube connection assembly of a bicycle frame, comprising: a stand tube ( 12 ) having a top end; a front portion of the top end of the stand tube ( 12 ) being combined with a front upper bi-forked tube ( 14 ) and a rear portion of the top end of the stand tube ( 12 ) being combined with a rear upper bi-forked tube ( 18 ); a five-stub tube ( 121 ) being installed at a bottom end of the stand tube ( 12 ); a front portion of the five-stub tube ( 121 ) being combined with a front lower bi-forked tube ( 16 ) and a rear portion of the five-stub tube ( 121 ) being combined with a rear lower bi-forked tube ( 20 ); the front upper bi-forked tube ( 14 ) and the front lower bi-forked tube ( 16 ) being connected to a head tube ( 22 ) at distal ends away from the stand tube ( 12 ); the rear upper bi-forked tube ( 18 ) and the rear lower bi-forked tube ( 20 ) being connected to a rear connection end ( 24 ); wherein a bicycle frame ( 1 ) may be formed by welding the combined plurality of tubes together, in which the front upper bi-forked tube ( 14 ), front lower bi-forked tube ( 16 ), rear upper bi-forked tube ( 18 ) and rear lower bi-forked tube ( 20 ) are each formed with a V shaped bi-forked portion (A); and the stand tube ( 12 ), five-stub tube ( 121 ), head tube ( 22 ) and rear connection end ( 24 ) are each installed with a V shaped combining portion (B); wherein each V shaped combining portion (B) is engageable with each V shaped bi-forked portion (A), such that assembly of the bi-forked portions (A) and the corresponding V shaped combining portions (B) enable the bicycle frame ( 1 ) to be formed.