The problem is that the train station near the start is across the bay from the train station that the train from Davis stops at. Riders from Davis and Sacramento who are going to San Francisco have to get off the train at Emeryville station and take an Amtrak bus from there. So I am not sure how that is going to work with the tandem. You (MojoGirl) might want to make sure you can actually get your tandem to San Francisco via Amtrak.