I got the tire very lightly used, but the previous owner had blown the bead off the rim which wore down the rubber covering the wire bead. Long story short, it came off the rim again (I did get a season's use out of the tire), and did enough damage that it won't stay on if I inflate over 40-45 psi. Not exactly confidence-inspiring, considering I use it instead of standard tires to prevent crashes. At any rate, I know about the internal lip, but I was hoping for some way to replicate it; maybe some esoteric drill bit with a flange on the end that you shove in after drilling the main hole. I know it is a long shot, but it would be awesome if possible.