first I'v made a whole bunch of drawings of bikes from a book called "100 best bikes" I took my favorites and drew them.

heres the first one:

 















website: http://www.strida.com/en/main/

and the second

website:  http://brompton.com/

and finally:

website: http://www.europeanconsumerschoice.org/outdoors/puma-pico-bike-design-award/