The break-in oil Triumph uses in our bikes from the factory is a 10W-40 semi-synthetic oil. I would say you probably want to use the same type oil for at least the first 500 miles and then change over to a full synthetic.

Tom

Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety. Benjamin Franklin, US author, diplomat, inventor, physicist, politician, & printer (1706 - 1790)