Intrigued by an ad/review in some mag, can't remember where: the cog is bolted to the rotor mount and you flip your wheel around. Front brake only of course. While I've never done a fixed gear roadie or otherwise I was wondering your thoughts on this. Pedal strikes would be horrendous I'd imagine, and you couldn't go very fast down, but it'd be fun for the engagement right? Or more frustrating than enjoyable?