I was searching the shelves in a thrift store and came across a military buttpack made to use with webbing load gear, much like a civilian “fanny pack.” I immediately saw the potential for use as a bike bag: with all the MOLLE webbing mounts on the back, it could be mounted on a rack as a pannier or looped over the handlebars.
I found a Timbuk2 Metro model mini messenger bag in a thrift store and saw the potential to use it as a small pannier bag. I added a couple plastic carabiners to the existing shoulder strap D-rings and it fit perfectly on my Topeak Explorer rack without any further adaptation— truly a 60 second project. I would consider this a fair weather rig as the bag is not waterproof and the top of the bag has a simple flap closure. It makes a perfect size for tools, snack, wind shell and camera.
In a previous post I showed how to make a rack trunk box from a plastic 30 caliber ammo can or dry box. To continue on this theme, I put together a rear pannier using a plastic .50 caliber ammo can.