They can fatigue, but it has nothing to do with the tires you run.

If you jump it repeatedly, the excessive shock loads may do it, even more so with a heavy bumper/winch combo up front.

Good thing is they are adjustable, and you can compensate for the fatigue.

"A young man who does not have what it takes to perform military service is not likely to have what it takes to make a living." - John F. Kennedy

Proud owner of an 88 Montero (with a blown engine).