Two stage quick-release structure for foldable bicycle

A two stage quick-release structure for foldable bicycle, comprising:

• a first tubing member, comprising a first connecting member and an assembling portion, the first connecting member being disposed at a lateral side of an axial opening of the first tubing member, the assembling portion being disposed on another side of the first tubing member which is opposite to the first connecting member;
• a second tubing member, adjacently connected to the lateral side of the axial opening of the first tubing member, the second tubing member comprising a second connecting member, the second connecting member being disposed at a section of the second tubing member which corresponds to the first connecting member;
• a first pivoting portion, passing through the first connecting member and the second connecting member;
• a first buckling portion, assembled on the assembling portion;
• an elastic hook, pivotally assembled on another side of the second tubing member and corresponding to the first buckling portion, in which another side of the second tubing member is opposite to the second connecting member, wherein when the first tubing member is rotated to connect with the second tubing member by the first pivoting portion, the elastic hook correspondingly buckles with the first buckling portion;
• and
• a safety fastener, pivotally assembled on the first tubing member, the safety fastener comprising an extended handle, a second buckling portion and a second pivoting portion, the second pivoting portion being disposed at one end of the extended handle, the second buckling portion being disposed at another end of the extended handle which is far from the second pivoting portion, wherein when the safety fastener is rotated to come close to the elastic hook by the second pivoting portion, the second buckling portion correspondingly buckles with the elastic hook.