Weight and Balance
Sway is a fishtailing motion of the trailer, caused by external forces that set the trailer's mass into lateral motion with the trailer's wheels serving as the axis or pivot point. The motion is a sideways seesaw. All conventionally hitched travel trailers will sway slightly in response to crosswinds or the bow wave of an 18-wheeler overtaking from the rear. The good ones will need little correction by the driver and will quickly restabilize. Only poorly set-up trailers will continue to sway after the force that caused the instability has ceased. In fact, in poorly balanced trailers, the sway motion may increase until control is lost. Unfortunately, most evaluations of sway problems focus on the hitch or the tow vehicle, but the trailer's weight distribution often is the primary cause.
Following are points on how to tell a well-behaved travel trailer from a poor one, and how to correct a problem in a trailer that you may already own.