Lay it Flat

Why not lay it flat, instead of standing it up? This shape will rest naturally on its side without moving.
Street sports athletes like Skateboarders, inline skaters or BMX riders are alike. They love extremes, things out of the ordinary, radical ideas, etc. They will not carry any luggage while they are playing most of the time, even water bottles. In order for them to carry anything, we need to make it a part of their outfit or fashion. We may need to also design some harness, pouch or pocket of some sort.