SuperLJ, thanks for chiming in! I suppose that's what happens when one tries to over-analyze everything before experimenting-- you create hypothetical problems that don't exist in reality, and I am guilty as charged. I was actually thinking the shouldered bolt would be an issue since Grand Bois mentioned the Simplex hanger is thinner, but I should have just pulled a Campy RD off of one of my current bikes and tried it before posting here! And yes, GB, I should have taken the "only one way to find out..." approach.