There is no such thing as standard motorcycle gear oil, and if your bike is shaft drive, you're going to need the protection of a limited slip gear oil.
Motorcycle gear oil page
Whether your motorcycle has a two-stroke or four-stroke engine, getting the gearbox oil right is essential. Your bike probably has a wet clutch, in which case it shares your motorcycle’s engine oil.
However, if you’re riding a shaft-drive motorcycle, you’re going to need limited slip gear oil too, providing the durability and protection of a full synthetic formulation created by liquid engineering.
Castrol Scooter Gear Oil 80W-90 API GL-5 especially formulated for scooter gearbox, providing excellent gear and bearing protection under heavy working conditions and high load.
Castrol Scooter Gear Oil contains extreme pressure additives, that
The high load carrying capability ensures gears operating under high loads are protected, prolonging component life.