I'd have to say, it's a tossup between either "Richard's Bicycle Book" by Richard Ballentine or "Anybody's Bike Book" by Tom Cuthbertson. Both very much a product of their eras. I read them endlessly, for the techincal information as well as the "culture" aspects. I'd say they were the first real expressions of "bike culture" in the 20th century US. Or maybe I'm wrong. Either way, both are great books. I'd probably give the nod to Richard's if I had to pick.
Tim
-- Tim Fricker bikes@vienna, llc Vienna, VA, USA Recumbents, folders, tandems, commuters, etc.