there are courier bags and careeriour bags. the careeriour bags are over couple hundred dollars and you can fit a small village inside, or a copy box and some. Unless your paying rent with a bike, bag and radio, you don't want or need something so big. There was a kid at the naccc's that had probably the largest custom bag I've seen, he was from chicago? mabe, I don't really know, but he had a huge bag that he could fit a small, but full grown, skinny adult male inside, all of him except his knees and up and head, and ride with this grown man on his back.