>>2082675While I was hitchhiking around the US, I carried a lightweight bivvy/liner/CCF pad and GI poncho, Sawyer mini filter with both a clean and dirty dromedary bag for gravity filtering, two sets of quick-drying clothes (think board shorts, dry-fit shirts and wool socks, and hang the wet ones off your bag to dry them), an alcohol stove and Stanley adventure cook pot, a 6oz bottle of baking soda (as toothpaste and deodorant), and Knorrs and gorp took up the rest of the space. Aside from topping up my food periodically, that was all I needed for several months until I ripped out my shorts.
You should also carry a spare tube and bike pump, and maybe a chain tool if there'll be any real long stretches where you couldn't get to a shop. If you're competent with a needle, do something like pic related. All of those bags, including the zippers, straps, fasteners and the form for the seat bag, were made from a duffel bag I picked up at a second-hand store for $7, and getting the weight off your body and onto your bike frame will make your ride so much better and make you look more like you planned a tour and not just hopped onto a bike without a plan, keeping a lower profile. The bivvy roll can be strapped in front of the handlebars as well; if you do it right, the only thing you'd have on your back would be your dromedary.
