It's tight, it hasn't separated. I did what you're talking about to a wheel several years ago, put a small hole into the material and injected some epoxy resin. Seemed to fix it but not sure how it held up long term.Steve - is the rubber tight on the wheel all the way around? Mine is loose on the top half so it spins like motorcycle throttle when gripped. I have thought about trying to inject some epoxy or other type of adhesive into it but haven't found one yet.