my gf went to chico state, so we often go back to visit friends/family and take our bikes. it's crazy flat, so coming from a fellow sf rider you might find it a unique break from the norm. pullins cyclery seems to be the best one i've noticed. i've been meaning to ride out to the paul factory to check it out, but haven't yet had a chance to. i notice a lot of bikes/cyclists but not many fixed, though i haven't been back in almost a year now. everyone there seemed to ride cruisers with ******** chopper bars and i got weird looks for my "race bike".
also, i always get taken to a nice little bar called duffy's - fyi booze is CRAZY cheap in chico. it was like $4 for knob creek. when you go to college in the sticks there's not much else to do than get schnaukered. and if you aren't veggie, a place called nobby's has really great burgers. what else... oh it should be hot as all get-out too. bring your shorts, place is a fricken sauna. go swimming at some "swimmin hole" called upper park or something.
amtrak should have bike cars, sorta like caltrain. we've taken it as far as sacramento with our bikes. we usually bart with our bikes out to richmond station, then transfer to the amtrack stop and vice versa to avoid the bus from emeryville>the city via the bridge. if you have any more specific questions pm me and i can ask my gf.