What is the width of your 42T 130BCD chainring? I'm wondering if it's designed for 1/8 chains, 3/32 chains, 11 speed chains, etc. Answer: USAmade rings were designed to use 3/32" and 9 and 10 speed chains. We fit the ring to a brand new 11 speed chain with no problem, though it was slightly tight. The difference in teeth thickness design between 10 and 11 speed chainrings is about 0.005 of an inch. So, I would not hesitate to try it. The steel chain would settle into the ring on the first ride.
Are spacers needed for the 104/30T ring so the chain will clear the spider? Answer: USAmade 104/30T is threaded and has a 2mm setoff. It works on most set-ups.