You may have noticed, but I have a small fascination with disc braked cyclocross bikes. They're not UCI legal, but I'm more Graeme Obree than Lance Armstrong so I'd run it. I saw a Fixie Inc bike this weekend that has replaceable derailer hangers on both sides to swap between geared and single speed configurations. This allows the force loading to be communicated through the derailer hanger to the seat stay and chain stay in a more controlled manner than a mountain bike style disc tab which usually requires a gusset to be welded in the crotch of the triangle you see below. This is all well and good as long as the hanger and it's connections (two M6 bolts it looks like) can bear the loads of braking. It looks aluminum and it looks quite cantilevered so I'll give it one, maybe two seasons. However, its owner knew the guys that made the bike and had a ton of confidence in it. More interesting, is that Fixie Inc is making their own road disc hubs. That could be huge. Their web site is a little avant-garde for me. If you find the hubs, let me know.