In a lot of places it is almost impossible to find straight gas so you pretty much do what you have to do or push your bike. 10-15% ethanol is good for making a few more HP (example: 2009 Titan makes 300 hp on gas and 320 hp on E85) but you fuel mileage suffers. I average 200 per tank on my XR with straight gas and lose about 15-20 miles with 10% ethanol.
Unfortunatly even though E85 is counter productive (I.e. costs more to make than straight gas) it is here to stay because it does effectively decrease exhaust emissions.
As far as your bike goe it is should be E85 compatible because all vehicles are supposed to be capable of running flex fuel. Ethanol is more corrosive than straight gas so it is tough on fuel lines and on some fuel pump components so the only difference between flex fuel vehicle and non flex fuel vehicles is the materials in the fuel pumps and the fuel lines.
Retired USAF, IYAAYAS!
2008 V-Star 1100 Custom Bobber project
2011 Crimson XR with Forged Highway Bars / Hard Bags / Passenger Backrest, Ness parts including Smooth Layback Plate Frame/Mount / Rad 3 Mirror / deep cut grips / drivers floorboards /shifter peg / brake peg / passenger pegs. Witchdoctor black rack, Lloydz filter / timing wheel / VFC III, 7Jurock windshield, Drag Specialties seat.