A guy I know had them done, I guess by the place he got the re-bar from. Then he sold the extra rings to anyone who wanted them. I guess it was pretty cheap because he only sold the rings for 4.00 each. I'm not sure what the over-all diameter was that he had them rolled to. But they were just slightly bigger around then the rim. A few well placed clamps and a little muscle power and they went in pretty easy. In fact, we popped them in, and trimmed them, and then only used the clamps on each side of th eweld as we went. They pretty much stayed in on their own once the extra was cut off. I figure they should help ward off any deformaties from rock smacks. We'll see I guess.
If you need any specifics on the rings, pm and I'll get the info from him, for you.