I've been running Bighorn's for more than 10 years now on my old 2004 900.
Here's part of a post I made from years ago:
The 25x10x12 Bighorns actually stand closer to 26 1/2" tall. For day to day use, I don't need a lift kit but when loaded and coming down hills into a corner, I do get a little rub in the front end.
Basically, 99% of the time, no rub but if I got in a particular situation which pushed down the front suspension, I could get a rub.
I did install a lift kit but wouldn't recommend that unless you need it. I live in very hilly land and didn't care for rise in the center of gravity.
I don't know if they still stand 26.5" tall from the factory.
I've carried heavy loads (enough to drop the bed to the rubber stops) and never had an issue with the tires.