I'm using 2 ammo cans and 2 lap top bags as the hard and soft panniers for my bike. You can find ammo cans at pawn shops or outdoor army surplus stores for 1/2 of the online price. I paid 12 for the 2 laptop bags in new condition at a thrift store. The nicer laptop bags are cool because they are well made and have a re-enforced flap inside you just push down and the bottom goes flat and sturdy. I have carried 2 2 liters of soda in each bag easily. The ammo boxes you can lock with a little steel chain and padlock, I use them for my utility needs. I also picked up an army canteen bag, insulated with a big closer flap, will velcro or zip tie to anything and fits well as a quick and easy tank/fender bag. Goes really well zip tied up above the rear tire where no one can see it
