Folding bicycle frame manager

In order to enhance the rigidity of our frame, the main tube of the frame acts vertically on the head tube in the shape of a "bulge". This "bulge" is specially designed to increase vertical strength. We call this technology PowerBulge TM. This makes it extremely strong in the vertical plane of the bicycle front frame that bears the greatest pressure. Another advantage is that when the main pipe of the frame approaches the head pipe, its main pipe also contracts, thus making the folding more compact. This is a patent of big American banks.