The loop is 31 miles, and the total ride starting and ending at the SF Ferry Building is about 60 miles. Approximate route (I’ve since been told that one of the roads Google shows is not actually passable). Beyond just the length, I hear it’s moderately challenging – I may have no idea what I’m in for. Of all things, a Yelp review about it.
Some people like to start early, some like to start late, so to compromise: meet at 10AM at the Ferry Building (or get there at 9:30 to eat some pastries / chilaquiles / etc at the farmers market with me).
Let’s do the loop clockwise so we can get the hardest/longest riding done first and then stop in Fairfax at the Iron Springs Brewpub: http://ironspringspub.com/