Ok, it's back to the bike shop tomorrow then, thank you. They better not charge me to have it reversed though, the amateurs. I have a feeling I might like this tire a lot better once it rotates in the other direction
I have a 120-80-18 btw. It only touches the fender on the rear edge of the fender (the lowest point of the fender when it's mounted) and if I press it together a bit by the side edges of the fender then the tire clears perfectly by about 5mm. I think that if I'll just try to shape a little stainless steel clamp so it'll clip on there and keep it in slightly rounder shape I may not even have to raise the fender at all.
I'll report back as soon as I've tried some things