i'm not in s.f., but i figure the buses aren't any wider than here (lou. ky.). we have racks on the fronts of the buses, but not much beyond a normal wheelbase bike will fit on them.

i have to qualify that though, by saying my cargo experiment has about a 5" longer wheel base than a b.d. (and my normal bike is a stretch cruiser, which is why i measured it in the first place), so maybe the real manufacturers knowingly designed to the limit and it might fit. i know i measuered one once to take a try at building something that would just fit, but the max that i measured wasn't much more than a good sized ten speed, so i never bothered with it.