SFBC Rec Ride: Four Corners Ride

"Tour San Francisco's outer limits on an all-day ride around the
perimeter of our diverse and enthralling city. Explore world-famous
landmarks as well as sights that even locals may not have seen before.
The ride is 40 miles, start to finish. We'll keep a friendly pace but
expect some challenging hills and strenuous riding. Bring lots of food
for on-the-go snacking and one official picnic break. Hardy, hungry
survivors are invited to the Park Chalet for post-ride beers and
munchies."