This page lists great motorcycle trips around Sydney. 

Ku-Ring-Gai National Park loop

4-5 hours (with stops for drinks and food)

Meet at the foot of the Harbour Bridge on the north side, loop through Ku-Ring-Gai National Park, Palm Beach and North head Manly back to the Harbour bridge. This ride can be cut short anytime after Church point to make it faster if there is not enough time.

Putty Road

5-6 hours (with stops and travel to starting point.

Meet at McDonald's, Windsor Road & Groves Avenue,  Windsor NSW 2756

End up at Milsons Point, NSW 2061