Pannier/backpack conversion

Yeah it's a sick idea. I do this with two little canvas ammo bags, Polish military surplus from ebay, twelve bucks a piece. I sewed coroplast sheets into them so they'd be stiff and lightweight. I made straps for them out of my great-grandma's old truck's seatbelts, and each pannier doubles as a shoulder bag. No need to spend a bunch of money!

couple of videos on youtube on this subject, see the beach bikebums with the removable backpack/panniers all the time

The panniers I have are pretty easy to carry, even when fully loaded. I'm planning on picking up a $10 collapsible 20L backpack to go with them for items I need to bring with me when leaving my bike. I was considering bringing a regular backpack too at one point but it's just not worth the weight.

Also, a lot of panniers have adjustable straps that come with them, or you could make straps out of old material. Line them with some of the white lightweight shipping packaging foam and adjust them for your shoulders and bam, cheap backpack.

Cool idea. I was thinking of getting a cheapo set of 37L panniers from aliexpress, then keeping my 80L rucksack to sit on top of those. I do a lot of hiking and multi day trips into mountains when I travel so I need more than a daypack.