06-15-2017, 12:29 AM
In my experience, it's normal. Many roads are crowned to allow drainage to either shoulder. So, while you're riding straight, in reality you're riding on the left side of the tire (imperceptibly) due to the road grading. 6k miles is pretty good longevity from a front radial. I imagine your R1100RT goes through front tires too (all of my Telelever bikes seem to eat front tires for breakfast).
Cupping can also be caused by improper tire inflation and/or heavy use of the front brakes, especially on heavy bikes.
Cupping can also be caused by improper tire inflation and/or heavy use of the front brakes, especially on heavy bikes.