I had a shop install a 150 rear and a front. The torque brake rod :thumb: didn't need to be bent. I've measured and if my eyesight is right their is a 1/8" between the tire and the brake torque rod. As far as the other side their is plenty of room for the chain gaurd.pilot powers.
on the stock rim?
The shop that I went to made me sign a "dangerous condition exists" waiver just to put a 140 on the back. I'm sure it's just for liability reasons, but still, I personally wouldn't go past a 140 on the stock rim.
From what I hear, the stock rim "pinches" a 150 so that it has a different profile than it's designed for. The results of this include more wobbly cornering, and faster chickenstripping because the edges of the tire won't ever touch the pavement. I would buy a katana rear wheel and do that swap. If you don't like the idea of bending the brake torque rod, the stock rod from a bandit 600 fits perfectly, and has adequate clearance.