In the pictures, the bag is resting on one of those petite TA racks that mate with MAFAC Racer brakes. There are two stabilizing and adjustable straps on the sides that attach to the rack along with center-rear strap. We used the handlebar straps for this test. I have a decaleur on the way to try that out as well.
We're going to add two small pockets on the backside, in typical rando style, But this is more blue collar than Gucci, so we hope to keep it affordable. Also have a trunk bag in the works.
After we get the bugs worked out, we’ll start production. But we're pretty happy with this prototype, so I don't think this will be too far off.