Yeah, I've seen that done and it looks like a good place to mount it. I have an old-fashioned Pyramid-brand frame pump (one of those jobbies where the hose stores in the handle, and you switch it to the business end to use the pump) that came with two brackets that fit around the frame tube, and the end of the pump spring-loads onto studs on the bracket. That kind of pump/bracket would work, and since it's chrome plated would probably look kind of retro-cool on my Trucker. I have a mini pump on my mountain bike that clips onto brackets that mount to bottle-cage bosses, but I've never seen brackets that would allow a frame pump to mount behind the seat tube. Any suggestions as to where one could find such a thing?