Originally Posted by Retro Grouch

During that era flutes were popular as a weight reduction technique. Other parts, like brake levers commonly had a neat series of holes drilled in them for the same reason. Some guys would amuse themselves by drilling little holes in their brake calipers, derailleurs, chainrings etc. It is a lot of work to get all of the holes evenly spaced and it didn't remove all that much weight either.