The Pannier is secured to seat post collar mount - when fitted like this the Pannier is wobbly because the mounting points are closer together. On my other bike with the pannier fixed to seat stay mounting points it is solid.
This is my bike for Touring when I need to travel and is made easier with a folding bike.
As you can see the seat stays are much lower (It's a Montague folding bike and folds at seat tube).
The seat stays don't have the usual pannier mounts - also they are much further away so P-Clips won't work.
How can I get the mounting points further apart?
Solutions:
1. I thought about getting a seat post mount pannier and modifying it and bolting my pannier to it
2. attaching to an accessory bar somehow like this
https://www.sjscycles.co.uk/accessories/thorn-accessory-bar-mk1-t-shaped-105-mm-extension-222-mm-0-deg-satin-silver/I'd be grateful for any help, the wobble from the pannier when loaded is not fun!
The woodwork holding my mudguard on is just a temporary fix.