I use 6 zip ties to hold it down and it never moves.

I started with the porteur rack and it was overkill. Plus I didn't like how high everything sat. A true porteur rack should just clear the front tire and fender. Then I went to the Nitto rack and large Wald basket but wasn't quite as stable. I then added a second pair of struts to Mark's Nitto rack (from Rivendell) and it was much better. I went with the smaller basket because I really didn't need the larger size for most day to day riding. Hope this helps.

First Gamoh Porteur rack.



Replaced with Mark's Nitto Rack with single strut.

Replaced with double strut and smaller basket. I keep a net on the basket and a few toe straps to fasten things down.