Right, but the contour of the fender is what I'm talking about.
See yours...
and mine...

I can't find a pic with the same low angle, but I hope I'm getting my thought across.
There was clearance between the mounting bracket and the fender on mine, I bet it's a lot closer to the Speedy fender. The fender itself doesn't have as much curve around the tire. Anyway, I'm amazed it didn't rub until you got in the 90s, mine rubbed on the mount at about 40mph.