I might find where to crosspost. Maybe suggest. Currently I've got a Topeak bag with velcro but the two straps on the front (or back if you switch the bag around) only lines up on one side. So I can velcro the left side so it doesn't slide forward. The horizontal velcro underneath holds decently. But I need ways to fasten the bag better. So rather than asking a one off question, I hope you understand and appreciate the underlying extent that I'd prefer to ask extensive options and plan to get bunch of kits or being aware whenever I need any.
I have a few setups or may change it up later. But for doing meal deliveries, the zipper on this topeak is quick enough I can get a bike lock out quickly. It matters.
So while I could get a different bag, etc, any option can't drawback to different problem. So unless I am shifting this bag to another bike, etc, or there's a bag that works perfectly, I might lean toward focusing on improving this setup. While also certainly asking more overall ideas what pannier bags to buy next time.
For example I'd love to know some secure but easily removable ties like those silicone Nite Ize ties or something like a round cord that can tighten. The Topeak bag has a plastic loop I want to basically tie down to the rear of the bag. Branch it left and right so it holds. One anchor point on the Topeak, two anchors down to the rack.
I'm not sure how to secure the bottom velcro any better.
The bike pannier rack comes with its own bungee strap. And the rack is long enough I can maybe remove the Topeak bag and attach a small box, think like personal pizza size box, etc. And then try to re-attach the Topeak bag, tip up one side so the pizza box is strapped down and able to wedge the Topeak a little crooked sitting over top on the rare occasion I get an order like that.
Otherwise eventually I can post my other setups and ideas for other commuting. I've got one of those Styrofoam cases. And might eventually get an Ortlieb XL for grocery runs or travel.
For now, really I'm just wondering if there's a cheap off brand or extremely good pannier bag or way to strap this Topeak down. If there's also a list of kinds of straps I can buy. TPU straps, or ways to custom add my own anchor points to the bag, or add a Topeak quick release somehow to this bag.
Or anything I'm not thinking of to have capability to carry small pizza box and still have my utility bag and side panniers, without carrying it in one hand. Not good. Or spending too much time to rig it and not very secure. I would love to know a bunch of options and just buy a ton.