Cantilever Bridges

You can already add cantilever brake bosses as described at: bikecad.ca/canti_bosses. I'm not sure if you are referring to something different when you speak of cantilever bridges. If so, please explain what kind of feature you'd like to see.

Thanks for the clarification. I will try to add that to a future update of BikeCAD. In the meantime, I represented a bridge using the cable guide option as you can see below. Cable guides are always shown as though they are attached to the surface of the tube, so in order to make it look like the cable guide was offset some distance from the seat stays, I made dimension D in the cable guide dialog box extra big.