Thank you very much everybody for your comments!!
In response to the below comment, the engine is cosmetic (sadly).
Information on the suspension...
The rear suspension works by using the stretch of two rubber two-holed technic bits. The front suspension uses springs taken from the yellow spring pieces, and it is actually quite easy to do so, since these pieces use rubberized elements, and not hard plastic elements.
May 21, 2012
interesting bike, does the engine work or is it cosmetic? nicely styled.
I like it
May 20, 2012
This is really cool, there is nothing bad to say, so perfect work.