Which bike? The 630 manual says "Recommended fuel: premium grade UNLEADED fuel (R.O.N. 98).". I have used every grade of fuel available here, with no ill effects, even ethanol. I will avoid ethanol if at all possible, though. I do the same in my cars. The ethanol avoidance may or may not matter. It's just personal preference.
Basically, I avoid ethanol unless I have to really go out of my way to do so. If there's premium available, that's my first choice. Some places around here even put ethanol in the premium stuff. If that's what they've got, I'll go to another fuel station, or just put 87 in.
