I'm also not getting the connection between class divides and cycling. Are you trying to argue that cars use disproportionate resources and that by cycling we (Americans) would be helping better spread those resources to other nations? I think that argument would work better than comparing classes within the US, since a lot of lower income folks in this country do drive and do have cars.

One angle you might be able to use could be healthcare. Maybe you could make the argument that by cycling everyone would be in better health and there would be more medical resources for those in need. It's stretching it...but you might be able to make that argument.