Baubike by Michael Ubbesen Jakobsen

Inspired by Bauhaus design, the epitome of modernism, the BauBike makes artistic use of clean lines and geometric shapes. Creating a functional ride and a piece of art through design, the frame features squares and equilateral triangles limiting all of the lines to 60 or 90 degree angles. The extra open end piece over the back wheel gives you room to add an extra seat or basket.

source: DesignCombo