Unless specified otherwise, all of our tours use asphalt roads, so we recommend against fat "knobby" tires if you are bringing a mountain bike. On flat coastal trips, nearly any bike style is fine. For our hilly tours you will want a lighter road or touring bike, with higher pressure smooth tires, and a wide range of gearing.
If bringing your own bike, we strongly recommend that you have it serviced in advance and thoroughly inspect tires, shift and brake cables and chain. Also, please install a bright L.E.D. taillight for maximum visibility.