I am trying to obtain a few of those small threaded studs that are on some brands of outer chainrings. They keep the chain from wedging between the crankarm and spider in the event of an overshift. If anybody has any dead rings with such a stud and would be willing to part with it, I would be very appreciative. My Stronglight 106 crankset outer 52T ring has one. What other brands of rings have such a removable part? Many thanks in advance.