Have used the Topeak Super Tourist rear rack, with the Topeak MTX Trunkbag DX 12L version. They have a sleeker 8L size of bag, along with a 16L one that has integral panniers that pop out if you want them. Not the lightest stuff around, but durable and very functional. I like them. Wish the latching mechanism had a positive-locking feature, though it seems to snap-to and remain attached to the rack just fine. Easily removed, carried along wherever you're walking to, and is quickly snapped back onto the rack.