Crankset - The original intent in the sketch was to give a movement to the piece, since the theme is to express aerodynamic contents, combining shapes with smooth areas and other more tense "triangular" areas. 

In the photo of the final product the original intent of movement is amplified by plays of light because of the glossy surface finishing, that also enhance and lights up the fibers of the crank, opposite to the matte surface finishing on the chainrings.