The API oil classifications in the old manuals no longer apply to motorcycles. I've posted plenty of info on the changes in motor oils and how these changes are bad for TWs. You can read some of those threads.
To make a long story short, I've switched to Mobil 1 Racing 4T in 10W40 for winter and Mobil 1 V-twin in 20W-50 for summer.
Avoid any oil labeled "ENERGY CONSERVING" or "EMISSION REDUCING". Use only oils with JASO MA certification.
Ashless dispsersants (ZDDP, etc.) in aero oils of any brand are not sufficiently robust for motorcycles. Aero oils need low dispersants to avoid plug fouling--aero engines are notorious oil burners. They can get away with low dispersants due to their very low operating rpm and correspondingly low necessary valve spring pressures, oversized wear surfaces, and premium materials and manufacturing process such as heat treating and induction hardening. Aero oils are very high quality base stock and not much else.