gwaereth, what would be a good size cubic dimension? I don't do any touring or anything like that, I usually ride only only in the city and once in a while I may go outside of the city for a couple of hours. I didn't know that the Appalachian's could be used singly, if I pick them up I will let you know how they work. There is a handle of top of them, that must be so that you can carry them when you are off the bike.