From what ive read and people ive talked too thats going to happen. Ill keep you updated on what i find.It is basically touching. It left marks just from me spinning it to check clearence. I did have extra clearence on the chain side however. Not much though. Maybe an 1/8th of an inch to the chain. Clse enough that it would hit the tire while running. I just measured the overall width of the bridgestone mounted on the 5" Behr at 6.25" if that helps you. I measured using two straight edges across the diameter of the tire on each side giving a clear gap to measure. It is a 165/625-17 Bridgestone Supermoto.
And for speed ya i have no way of knowing. Ill be gearing for each track.