The actual 49-Mile Scenic Drive is a little car-heavy, so BH and I made our own.
San Francisco is a beautiful city. It was cloudy, and biking doesn't lend itself to stopping and taking pictures as well as foot travel does, but it was a lot of fun. I'm actually not a very fast cyclist, so I like that about it, too. I can ride with friends without them thinking I'm a prick; I have trouble doing that with backpacking.