[Walt Fricke]

Mark - now I see what you were getting at. I can interpret the photo to show a hint of thread on the intact stub, and maybe also on the broken piece, so the two chain wheel parts could still mount, and as long as the break was deep enough in, the washer shouldn't bottom on the cam and you could get enough torque going. The perspective in the photo is a bit tricky - kind of like those puzzle drawings where first something looks concave, and then convex, so to speak.