This baby was designed by one Michael Ubbesen Jakobsen. From baubike.dk:
The BauBike is inspired by Bauhaus design. It is constructed around the geometric shape of the square and the equilateral triangle. The design is stripped down to clean lines and raw material. The design follows a set of formal rules, limiting the geometry to straight lines in a pattern of 60 and 90 degree angles in proportions following the principle of the golden section.