Rendering researches...

 The biker

 There are some proportion issues on this one, especially on the front wheel. It's too large and the bike itself is too short... 

Anyway, i 'm just looking for a good rendering. 

Technique : First pass : very free direct drawing using indian ink with a pen on bristol paper.

                   Second pass : three layers of indian ink wash tint   

                   Third pass : details with pure black and corrections.