Not sure it would warrant a tutorial. Its just a case of carefully lining the figure in a grey of your choice and then building up the layers of white until all there is is white :s
The black hasn;t come out too well in the photo as it is more defined in real life.
More down to my inability to take proffessional photos than anything else
Once again, very good attention to detail, and excellent white (i no how hard white is to execute well!) but the black on the front of the bike looks a little flat, maybe an extra streak of white over the raised areas? 6.8/10