Cool idea. Looks kind of "industrial", though.
Hmm, eliminate the drum in favor of a disc and make the sprocket aluminum, and I am all for it!
Actually, I just got my #35 rear sprocket today. It is a 40 tooth. That sprocket is much smaller than my 203mm rotor. So, I will be able to use a disc and sprocket on the left side considering the diameter of that sprocket.
Matt