A folding bike designed such that when the bicycle is folded, the front and rear frame structural members bypass each other in a non-overlapping manner except at folding and fastening positions using an axis of rotation at or near the seat tube, wherein the folding bicycle maintains a rigid riding position using an innovative fastening mechanism positioned to fasten by actuation of a member located not above the uppermost surface of the front frame, and which may be equipped with primary and secondary retention wherein the secondary retention may automatically engage when the bike is unfolded to the operative riding position.