According to the service schedule for my Piaggio Liberty after that first 600 mile oil change - the engine oil and drive belts are to be replaced at the same intervals.
Every 6214 miles...
Well, will likely do 5 or 6 oil changes on this 155cc aircooled engine during each 10000Km. Not one.
Crazy.....but it does have a spin on oil filter. Still -- 6,000 miles between oil changes! (My Scion gets them at 5,000)
Stig