I saw how set up can really create sway this past weekend. I caught up with a full size pickup pulling a probably 4x8, or 5x10 trailer with a Harley on it. Looked like all the weight was on the tail of the trailer, and they tongue was way high.
He was going about 50, and kept trying to speed up, and that little trailer was wagging that truck all over the road, then he would slow down and get it under control. I was a little nervous to pass him, but made it by him. I was cruising pulling a 33ft 7000lb trailer like an arrow with a properly set up Blue Ox.
It's amazing the difference the set up can make. I never would have thought about that little trailer swaying that truck that much. I should have had my wife video it to show how important proper set up is. They guy had plenty of truck.