We were pleased with our experience with Golden Gate Bridge Bike Rental. We showed up a half-hour before our appointment time and were able to get bikes for myself, my wife, and grandson immediately. The staff gave us a clear explanation of the route to take, including the ferry back to San Francisco from Sausalito. The bikes were in great shape and worked well for us. Note that all of the seats on the city touring bikes were somewhat narrow and hard, so do not expect a wide, plush seat. Rental included helmets, locks, a case for holding small items, and a very useful map.
A couple of tips for people who want to bike across the the bridge and take the ferry back. First, your starting point is going to be irrelevant because you will be biking back to the bike rental. We chose this rental place partly because it seemed closest to the bridge. However, that meant a somewhat longer bike ride from Pier 41 where the ferry dropped us back to the rental shop, compared to other shops closer to the piers. Fortunately, Golden Gate Bridge Bike Rental assured us that we would have sufficient time to get back to the bike rental if we took the last ferry back, and that they would stay open until 7:00 if necessary (way past their usual 6:30 closing time) to receive our bikes. True to their word, we found them waiting for us at 6:55 when we returned.
Another tip is to make sure you get in line early for the last ferry. We saw people lining up an hour before departure, but thought nothing of this, so we casually sat around eating our take-out fish and chips, joining the line minutes before it began to move. When it was our turn to board the ferry, the staff announced that we were the last three persons that could be taken because they were out of room for bike. Goodness knows what the two dozen people behind us did, how we would have returned to SF (we were too tired to bike back over the bridge), or how we would have returned the bikes (because the rental shop would have been closed and we were flying out of SF at 5:40 AM the next day). Repeat: get in line with your bike early!
We enjoyed many activities during our week in SF, and this one was definitely a highlight.