I was given one of these bike messenger shoulder bags with the seatbelt latch. I tried it out today and ... I don't understand why this would be preferable to a straight up backpack. It seems much more awkward.
@peterdrake They absolutely kill my back, and always have.
@gilhova Backpacks or messenger bags?
@peterdrake I'm fine with backpacks as long as I use both straps. If I use one strap, or if I wear a messenger bag with any significant weight, it doesn't take long for my back to start complaining