I'm getting ready to change my wheels to some PM Torque's. My question is that I currently have 16's on the rears, but the new PM rear wheel is an 18. Current tire size is 150/80/16. What would be the correct sized replacement for the rear, only in an 18? Dealer says their shouldn't be a problem fitting it to the bike, but that doesn't make it so. Not that it makes any difference, but the front is a 100/90/19. Any suggestions on size and brand would be appreciated. Just looked at a 150/70/18. This would give me a little over 1/2" lower of a ride than I have now. My current clearance is roughly 4.6", so I'd go down to roughly 4". Anyone know if I can go to a wider tire or higher aspect ratio to keep the ride height closer to what I have now in terms of clearance without having to change anything else out?