My cyclocross bike has braze ons for mounting a top swing derailleur. Currently I have no derailleur. Does any one know where I can get one that goes up to 50 Teeth on the front chain ring or what models are capapble of this? It looks like they only make them for Mountain bikes that go up to 44 teeth. I imagine that the curvature of the deraillure would prevent it from being set up correctly for a larger ring. Or will it just work the same anyway. I plan on running a bar con in friction mode. Thanks...