Well as pointed out in post #2? mass plays a part in this when trailers get really long. A 37' trailer has a lot of leverage on the tow vehicle, and the lighter the TV, the more it affects handling when a Semi comes upon in. Granted a Titan has upwards of 8900 GVWR, but a 3/4-1 ton have more and are more suited for towing long trailers.
In this case it is more about the length than the weight. When a semi approaches from the rear, it's bow wave is pushing against the rear of the trailer, and the natural reaction (Newtons 3rd law comes into play) is for the front of the trailer to swing in the opposite direction, which in turn forces the rear of the truck into the same direction and the front in the opposite direction.
To counter this a good WDH with sway control is required and is a must have regardless of what it towing it, even a 1 ton benefits from one. What the sway control does is when the trailer starts to pivot on the axles such as when the bow wave forces it to, the pivot points on the sway control react and apply opposite forces to keep it straight. What the driver feels in this case is that the entire rig is moving away from the approaching semi. Then when the truck moves past and that force lessons, the entire rig will be sucked over instead of just the trailer.
The longer the trailer the more leverage it has on the TV, the stronger the movement up front becomes, and a WDH with sway control is essential.
A Blue Ox is a great example of a hitch with sway control. I have one of the 1500# ones for my measly 28' long trailer and it is rock solid behind my F150. The entire rig moves as one when semi's blow past. I did have to disable sway control on the truck though as the truck was trying to counteract the hitch when trucks went by the other way on a two lane. It was the oddest sensation, felt like the back of the truck was learning how to hula dance.
As for the 5th wheel, those are a totally different animal as there isn't the pivot point off the rear bumper like in the tag along. The pivot point is directly on the rear axle, and far less likely to have sway issues.
|