The problem:Ortlieb panniers come with gurt big hooks and smaller inserts for the hooks, which make the hooks fit snugly on the rails of the racks. But these little inserts are a pain: they can fall out and be lost or twist and get stuck so it's difficult to get them seated correctly. BUT if you remove them entirely, the panniers rattle. (OK, this is not the biggest problem the world faces, hence the title thread.)
The answer: Put thick plastic tubing on the racks rails so their diameter is the same as the gurt big hooks on the Ortlieb panniers.
The "How to" section:i bought this on eBay:
Description: Clear PVC Hose Pipe Tubing - Food Grade - Fish Pond Car Aquariums Air Line Tube [10mm ID x 16mm OD (thick wall),2.0 Metre Lengt , Item # 261408670856 Qty: 1 Unit Price: 5.24 GBPI then cut it into lengths the same as the racks (these are the front racks from Thorn, I've also done it on the Thorn Expedition rear rack and the rear rack (Tortec I think) on the audax bike), then slit it lengthwise and popped it on (this is quite tricky as the piping is quite thick and is tough material). Like this:
Just a few tiny cable ties to hold them in place (not really necessary I suspect but I had 850 cable ties in a plastic container so why not?),
then:
some black spinnaker tape to make it look "proper" and Bob's your uncle.
so now those small tiny little miniature inserts from Ortlieb can go back into the bottom of the panniers and stop falling off/out/slipping sideways as they do.
Was this worth a fiver and an hour or so of fettling? Maybe. Of course I could have just bunged some Araldite on the little inserts so they didn't move, but then they'd be there for ever and one day I might want to remove them.