Originally Posted by
JohnDThompson
The "Gran Sport" vertical dropouts were stamped:
As you note, the track dropouts were quite thick, and even Blanchard ground for smooth faces. The Gran Sport dropout is just a little thinner than a 1010 forged dropout, but thicker than the stamped dropouts on entry level bikes.
Interesting the stamped dropout has enough metal for threads on the derailleur hanger. As best I can tell, that is the best reason to have a forged dropout, to accommodate a hanger. Track ends don't need a hanger, don't need to be forged. Not a lot of derailleurs prior to 1940, not a lot of need for forged derailleurs. Sure there always exceptions, but I can't think of a better reason for forging.