I have mentioned this in Mark's thread but didn't want to look like I was just being negative so didn't pursue it............BUT.............I have to ask, why
This has to be a solution looking for a problem
So what if the panniers wobble around a little (can't say I've ever noticed though)
I've done a fair few miles now, fully loaded two up, off piste loosing count of the times I've dropped the bike and thrown a bike with Varios down the road at 70 plus with the pannier taking the full impact (and saving the bike). Despite that, all mountings are still in place and doing their job
What happens when you drop the bike in a low speed spill

Will the main mounting now break beacuse there is no flexability to take up the impact

Or will all the force be taken up by the 'stabiliser' bar and punch a hole through the back of the plastic pannier
Please, enlighten me
Andres