Hi Ritchie!
Good to hear from you; just don't go past those skull 'n' crossbones signs -- yikes!
Duremes are nice tires, but do seem to have fragile sidewalls if one hits something just right (I think they'd be most vulnerable to sliding into a rock-lined hole).
Rual gave some great advice, and I can offer a further suggestion. If you happen to carry a Rema patch kit, it will often include an oval patch (two if it is the full "touring" patch kit with spares). For many years, having only the little hole-type tube punctures, I wondered what the oval guy was for. I got my answer when I incurred a sidewall tear much like yours. Applying a patch inside and out -- as one would on a tube -- did the trick for me. The tire continued for many hundreds of commuting miles with no sign of problems, though I did promptly swap it to the back wheel from the front, figuring a tear-out would be less problematic there.
A second large puncture patch on the outside wouldn't hurt. .75in is a good-sized tear.
Lacking that, booting inside with a bank note (cash bill) can really help, as most are printed on a tough linen-content paper. I've done that and smeared the equivalent of ShoeGood or SeamGrip outside and have done alright. If the tear seems to be progressing toward the bead, you may have to wrap a single layer of the bill around the bead itself.
I hope this helps, Richie. Any chance of a replacement arriving in the mail?
Please take care, and know good wishes are with you for a safe journey into and through the coming New Year.
All the best,
Dan.
