After break-in, say 3,000 miles, it is safe to use synthetics. The is a hot controversy over whether to use motorcycle specific oil or just generic auto stuff. There were several studies that indicated there was nothing special about motorcycle specific oil except the price. I use Valvoline Racing 20W50 when in use dino oil and Mobil 1 15W50 when I use synthetic. There are about a jillion synthetic motorcycle specific synthetic oil. They mostly cost 2-3 times what Mobil 1 auto oil does.