If it was me, and it's not, I'd use a 20-50 full synthetic SG or SG-JASO-MA or MA2 applicable oil. For one thing, the R3 has no oil cooler and the transmission and engine share the same oil. If it was just the engine, you could use an SG rated 20-50 but the gear sets and bearings in the gearbox will shear down the SG rated oil much faster than the JASO-MA rated oil. By shear, I mean the gears and the bearings will cause the viscosity index to drop, especially at the OEM recommended 10K oil change interval.
I'm using Rotella T 15-40 in my new bike but I'm changing the oil every 1500 miles. Interestingly, Rotella has been tested by Shell and meets the JASO-MA standard even though it isn't stated on the bottle.
Whatever oil you decide on using, make absolutely certain it has no molybdenum disulfide or 'Moly' in the additive package. Wet clutches fail quickly with a Moly additive.
There is a lot of hoopla about oil and especially motorcycle specific oil but the fact is (and I can back it up with test reports) that so long as you don't extend your change intervals and keep an eye on the heat cycles, any high quality automotive motor oil will do fine in a bike so long as it don't contain Moly.
It's also a proven fact that motorcycle specific oils cost appreciably more per quart than automotive oils. Let your wallet and common sense be your guide.
If, indeed I was to adhere to the OEM's 10K change interval, I'd run either Amsoil 20-50 SG-JASO-MA or the branded for Triumph Mobil 4t Racing. I run the Amsoil but I still half the change interval. I just keep the drain oil for my riding lawnmower, rototiller, push mower and my wife's car.
