Cheap Bike Bag From Army Surplus Bag
I was at the Army Navy surplus store, and came across some bags I thought could be repurposed for bike use. After some research I found out they're Swiss Army Bread Bags
from WWII. They have two leather belt loop straps that conveniently fit over handlebars. They're not much to look at from the front, as most of the leather ends up on the "back" of the bag. They are built super tough, bomb proof dare I say... The canvas over cover is probably close to a quarter inch thick, and holds it's shape. I also found while trying to wash it that the cover is water resistant. The leather straps are super beefy too, and the top one that the belt loops are stitched to is doubled, and gives the bag structure. I paid $14.00 but have seen them online for cheaper.
I set this one to use as a handlebar bag, but with a little modification you could easily use them as panniers too.
U-lock, and rain gear.