If you own a car, its hard to convince me that you save any money at all by getting into all the bicycling expenses on top of your (reduced) car expenses. Kind of like spending $60 to save money at BJ's or Costco. Also, going car free isn't realistic for a lot of people because cars do lots of things that cars can't, and they do it pretty efficiently.

The real savings I see is replacing a family's second car with a bike or bikes. You get so many diminishing returns on the second car when you have the first.