Why use a dual pivot fifth wheel hitch?

Answer:

So the trailer can flex in relation to the tow vehicle as road conditions may warrant, not only left to right, but tip forward and back as well. Now having said that, if your asking why this arrangement is preferable to the 2 5/16" ball and receiver used on gooseneck trailers that is a matter of standards adopted by SAE, SEMA, and other professional societies, along with the manufactuers of the coupling devices themselves. Most states have also adopted the new more standardized FAR. federal regulations concerning the testing and load limit criteria for class I thru V trailer hitches.