Trailer sway can be caused by crosswinds, lack of weight distribution, inadequate spring bar tension, a loose trailer ball, and a number of other things. Using a weight-distributing hitch by itself may help limit trailer sway by evenly distributing the weight of the load, but it will do little to improve sway caused by mother nature. This is where your anti-sway bar comes into play. It is important to know that trailer sway devices come in 2 types: those that reduce sway once it has begun and those that work to prevent sway altogether. Using a 2-point anti-sway bar (the most simple of options) serves the purpose of forcing your trailer through friction to stay straight. It helps to eliminate any plan between your tow vehicle and your trailer.
Sway control systems that reduce sway rely almost completely on friction to keep your trailer from shifting, preventing sway from increasing only after it has begun. There are 2 styles of friction sway control systems – independent and dependent.
An independent friction-style (more commonly known as an anti-sway bar) sway control bolts onto your trailer frame at one end and hooks up to a small hitch ball that mounts to the system head at the other end. It is the most common application for after-market purchase. By attaching to both the weight distribution system and the trailer frame, the sway-control unit supplies appropriate tension to help keep the trailer in line. Think of taking a tongue depressor and gluing it to a piece of construction paper. For the span of the depressor, the paper is more rigid. Same concept as an anti-sway bar. The only difference is that an interior bar telescopes in and out as your trailer moves so as not to create binding or bucking of the trailer as you drive. As you tow your tiny house on wheels, the friction pads inside the unit make contact with one another and create resistance to help reduce any movement from side-to-side.
NOTE: A single friction-style sway control (or anti-sway bar) can be used for trailers with up to 6,000-lbs. GTW. If your trailer’s GTW is between 6,000 lbs and 10,000 lbs, you will need two sway-control units, one on either side of the trailer. You may also want to use two units if your trailer is 26′ or longer.
Dependent, 2-point sway controls are built into weight distribution systems. These are the most ideal for those towing their THOW. These systems stave off trailer sway as soon as it begins by creating enough resistance to essentially force your trailer to remain in line. Typically, they rely on the downward force of the spring bars to apply frictional resistance to the brackets on both sides of the trailer frame. In order for the trailer to sway, it must apply enough force to overcome this resistance and make the brackets slide beneath the spring bars. This is almost impossible.
It is one thing to manage sway. It is quite another though to prevent sway altogether and that is what a number of the sway control systems built into full weight distribution systems do. They prevent sway before it begins! These systems may use a variety of different methods, like applying friction or tension, to force your tow vehicle and trailer to continuously ride in a straight line. But the bottom line is they are effective. As with the reduction category, there is two option for preventative management.
Dual Cam Sway Control systems use sliding devices called cams (a working definition of cam is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion or vice versa) to suspend the spring bars. One end of a cam bolts onto the tiny house trailer’s frame while the other end attaches to the lift bracket via the lift chain. The rounded metal hooked ends of the spring bars then sit in the cams. The controlled placement of the spring bars keeps the entire system secure while still allowing enough movement for easy maneuverability between the THOW and your tow vehicle.
Some weight distribution systems have 4 points of sway control built in. The four points are:
- 2 – where each spring bar connects to the head unit
- 2 – at the ends of the spring bars attached to the trailer’s frame
Typically, these 4-Point Sway Control systems rely on a solid connection within the head unit in order to ensure adequate tension. The other two points provide resistance as well, helping to ensure that adequate tension is applied throughout the system.
All said and done, this seems terribly complicated. I remember when we towed our tiny house on wheels back in 2001. We went through 5 states and – at that point – hadn’t even heard of a stabilizer hitch. We were incredibly blessed with a safe journey free of incident. When we moved on to our next adventure traveling around the country in a more traditional travel trailer we inherited from the previous owner a full stabilizer system. We had a stabilizer hitch with an extension shank. We had safety chains. We had an anti-sway bar. We had a backup camera pointed at the hitch area. Again we had no incident. This time we traveled over 30,000 miles without incident. But it took lots of reading, lots of asking questions, lots of weighing, and some moving of stuff inside our travel trailer front cargo hold. It was worth it though and it is what allowed this post to be written.
I wish you all safe journeys and I hope this post has helped you understand more about not just controlling sway but preventing it altogether.
Did I miss anything? Do you have any towing stories to share? If so, please do leave them in the comment section below.