Shouldn't hurt anything, may even help performance. The fuel companies have the world convinced that you need the highest octane fuel available. The truth is octane is just the fuels ability to fight detonation, or preignition. The lower the octane you can run the better. Just listen for pinging, and then go up as needed, Shogun is on it when he says that higher compression or ignition advancement requires higher octance because of the increased cylinder pressures. The same is true with forced induction or nitrous. Too high of octane will result in an incomplete burn, therefore less energy released in the combustion process. This can lead to carbon build up in the combustion chamber on the head, valve and piston face and cause hot spots creating an ideal condition for detonation and decreased performance. Save you cash. Listen for the pinging on hard acceleration when the bike is under a load, like being 2 or 3 gears too high for the speed you are going. If you hear it, go up a grade at a time until it's gone.