I'm bumping this thread because I tried Shoe Goo thanks to you guys, and it is *fantastic*! I had a new-old-stock Specialized Turbo OS 700 X 25 road tire, never used, but at least 15 years old (maybe more). When I put it on, the tread separated in several places right down the middle seam of the tire, exposing the thread casing (which was in perfect condition). I filled in those split seams with Shoe Goo, spanning up to 3 mm of a gap where the seam had split, and the tire is running beautifully! It does seem to wear very well, so I'll get some life out of this tire that I thought I'd have to throw away. Thanks!!