A place on the fediverse to share and discuss about commuting by bicycle
Arkel has oversized cam locks for those thick tubes.
Ironically, my small folding bike had massive pannier rack tubing, and I was forced to swap the cams on several of my Arkel bags. Eventually, I decided to buy a new rack with normal tubes, and life has been much easier. LOL
You can find adapters online.
Ortlieb sells extra large replacement hooks that fit up to 20mm tubing: https://www.ortlieb.com/usa_en/ql2-1-mounting-hooks-20-mm-and-adjustable-handle
Arkel also sells replacement hooks to fit up to 21mm: https://arkel.ca/collections/accessories/products/oversized-cam-lock
I have a RadWagon 4 with the same problem and I use this pannier that uses velcro straps instead of a traditional hook setup. I love it - have been using it for almost 6 years now and have nothing but high praise for it