It would be nice if BikeCAD could calculate the chain stay angle. It's the angle between chain stays and seat tube. This matters because both Campagnolo and SRAM list their road front derailleurs as supporting chain stay angles from 61 to 66 degrees.
My own calculation says in the design for my new road bike the angle is 68.5 degrees.
The angle is so high because my legs are 39.5 inch so the bike will have Zinn 215mm cranks, which need a very low bottom bracket drop in order to keep a reasonable cornering clearance.
So I guess I'll have to use a braze on front derailleur attached to a standard clamp with a special lug which brings the derailleur back about 1 cm and tilts it by 5 degrees backwards.
My current design: http://www.bikecad.ca/1328432348321