The way points of this bicycle route:
Start on Townsend, or King to Embarcadero.
there's a bike lane on Embarcadero, and if few pedestrians you can leisurely get on the Herb Caen way.
Golden Gate Ferries go to Larkspur and Sausalito, if you need to shortcut your ride.
Follow the signs to bike route #2. It takes North Point, which is relatively quiet -- but watch for tourist drivers.
more tourist drivers looking for parking. At the pier, turn left to go up that steep walkway.
big warning: tourist cyclists get in trouble here. You get back on Marina blvd, watch for cars turning right into Fort Mason. After that you can take the leisurely walkway if you promise to be careful with runners and pedestrians.
no, do not go on 101! From here, there's a bike lane AND a bike path!
on a cold day, sip a cup of coffee with a beautiful view!
follow directions to the bike path over the Golden Gate Bridge (to Marin Headlands and beyond). On week-ends, it's the West (ocean) side, other days it's the East (city) side. Watch for randomness of tourists.
follow #65 to go back to the east end of the Golden Gate Park.
alternatively, #95
restrooms
through the park, via the Haight Panhandle, all the way to Folsom Street.
#30 goes through the panhandle, which you access by riding the middle of Kezar Dr. Alternatively, take Page St (#32) rejoining #30 at Scott, or all the way to Market St, turn right on 8th Street (route #23)
