In 2005 I rented a specialized stumpjumper M2 from downtown San Fran, rode it over the golden gate, through Muir Wood and up Mt. Tam. Back down via the eldridge grade and hoo-koo-e-koo fire roads, then road via Sausalito and back downtown.
Felt like some kind of pilgrimage, although the trails weren't particularly technical.
Took all day, must have been 50 miles + pitch dark when I got back.
I had to keep the bike overnight (I hadn't arranged this) and was petrified the stumpjumper was going to get nicked from the hostel I was staying in! Took it back early doors, shop wasn't happy but what could they do!