Sunday, June 7, 2015

Trailer Life: Weight Distribution and Trailer Sway

When we purchased our trailer, we knew we needed a good hitch with sway control and weight distribution. On our Rockwood trailer, we had used a Husky hitch, and I rather liked that hitch, though we did have a couple of problems with it. Prior to that, I had used one of the chain hitches (see picture below), and I did not care for that at all.

Example of a hitch that uses chains. The sway or tension bars are fitted into the hitch from below, then twisted and locked into place.

When I told our salesman that I preferred a bar hitch to a chain hitch, he recommended a Trekker. After some research, I decided to give it a try.

The purpose of a weight distribution hitch with sway control is varied. First of all, too much weight in the front of the trailer will place excessive weight on the back of the towing vehicle (our truck), raising the front of the tow vehicle and causing loss of steering control, hitch dragging and braking difficulties. The key is to balance the weight over the axles and the hitch. The weight distribution part of the hitch does precisely this. Of course, you should also be very careful how you pack your trailer, being careful not to place too much weight in the front, where the storage bay is located on many bumper pull trailers such as our Coachmen.

Truck/trailer combo WITHOUT sway bars attached.

Truck/trailer combo WITH sway bars attached. If you look carefully under the storage bay at the front of the trailer, you will see more light beneath the trailer on the bottom picture rather than the top picture, which demonstrates that the weight has been distributed more thoroughly.
If you look carefully at the two pictures above, you will see the top picture has a slight dip where the hitch is located. The weight at the front of the trailer is exerting too much pressure on the hitch, causing the front of the trailer as well as the end of the truck to dip a bit. In turn, this causes the front of the truck to raise up a bit, giving less control to your front tires. The second picture, with the sway bars in place, evenly distributes the weight. I try to pack the trailer so there isn't much weight at the front of the trailer, so it is rather hard to tell the difference. In a badly packed trailer, the difference is much more noticeable.

But more importantly for me, the sway control aspect of a hitch is important. I especially notice its importance on high speed multi-lane highways. I usually hold my speed to 65 or below. As I've said many times before, most trailer tires are rated for a max speed of 65 mph, and I adhere to that. As a result, I get passed quite a bit. I can feel when a truck approaches to pass. It's like it is pushing a wall of air ahead of it. As soon as that wall hits my left rear trailer bumper, it seems to push to rear of the trailer towards the shoulder. This causes trailer sway, that nauseating fish-tail motion that makes a driver begin to feel a bit helpless. A good trailer sway system helps to mitigate such sway and return control to the driver. I also find that if I get as far right in the lane as possible, I am less affected by passing trucks. But passing semis are not the only causes of trailer sway. Wind is also a factor, and perhaps more so than passing trucks. Road surfaces can also contribute to trailer sway.

Side view of my hitch system. The long black horizontal bar is the sway (or tension) bar on this side of the hitch. There is another one on the opposite side. The chains are safety chains in case the hitch should fail. If you look closely, you might also see a single thin silver cable just above the tension bar. This is the breakaway cable. Should the trailer become detached from the tow vehicle, this will automatically apply the trailer brakes, bringing it, hopefully, to a stop.

Overhead view of the hitch system, with both bars visible.
The downside of using a sway control system is that your turn ratio can be reduced, which means you can't make really sharp turns. This really isn't a problem in transit, but it does become a problem when we are trying to park the trailer, especially in tight places. As a result, when we arrive at a park, Donna usually goes inside to register while I quickly remove the sway bars, which takes me between 5 to 10 minutes. I've seen hitch systems before damaged by making turns that were too sharp, and sometimes the brackets become damaged.

Overhead look at the hitch without sway bars attached.

Rear look at the hitch without sway bars attached. The sway bars fit in the round holes.

If you have a trailer of any size, you really need a good weight distribution hitch with sway control.

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