Just about every sort of motorcycling group is using RTS these days, not just sportbikers. It's a very robust oil at a very economical price at American Wal-marts. It's a Grp. lll (if that concerns you) but considering that wet clutch applications likely beat down just about all oils in relatively short order, I see no advantage to going to a higher quality oil. I built up a decent supply of both RTS and Delvac 1 (super-cheap during a Wal-mart clearance!) so I shall be using that for a while. Once that is consumed, I am serioulsy considering getting bulk Delo 15W-40 from a local Peterbilt dealership. I can get it at $1.50 per litre. The forty-weight XD-3 works as well, though it would be more expensive at around $3.50 per litre at the Esso bulk dealer.
John.