Originally Posted by
icemilkcoffee
Aside from French BB and headsets/stems, another thing to watch out for is the Huret or Simplex style rear drop-outs. These are not compatible with the typical Shimano and Campagnolo rear derailleurs.
Is there a way of modifying the dropouts to use shimano deraileurs? I did a little googling but I am at a little bit of a loss where to start. It seems that the shimano need a tapped hole to thread into for mounting where the simplex is fixed into the dropout?