Just for fun, I had a quick look at my Scorpion Rally, and it is indeed the 54R.... that's probably because I try to keep my speed just a hair under 106mph when I've got the front wheel loaded to 467lbs
Personally, I wouldn't worry about it. If it were a supersport track bike, then maybe, but a WR? That same tire is often used on much heavier bikes, and will see much more abuse that most WR riders will throw at it.
Originally Posted by yaw
Thanks Thumpididump. I didn't see your post before I posted. Anyone have the cheaper version evidently without a rating?