If you've spent any time in cycle shops then you'll see how expensive pannier bags are (as is most bicycle accessories; the top-end goods range from £50 bottle racks, to £100 pannier-backpack combos bags). Home-made bags on the other hand are as cheap as you can make them. So that's what I've been doing, or at least trying to do. Trial and error seems to be the method to use when you've no experience with materials, so, alas, that's the method that I've had to use.
HERE is a link to a design that my pannier-backpack is loosely based on. Although I've made a few changes to the design in the link:
- A black ~20 litre backpack replaces the pink courier bag.
- I'm using a thick bungee cord from Poundland in addition to the carabineer clips to act as shock absorbers on the rough roads.
- A kitchen chopping board from Tesco (for ~£2 in a sale) replaces the 1/4" plywood backing board (used because plastic doesn't rot).
- Some nuts & bolts from Poundland, and penny washers from Toolstation to fix the chopping board to the backpack (which should distribute the weight/stress around somewhat).