What Makes My Trailer Sway
According to the National Highway Traffic Safety Administration (NHSTA), every year there are an estimated 50,000 towing accidents. The majority of these collisions are caused by trailer sway. When the swaying increases intensity, the trailer can flip which could turn your towing vehicle. If you're towing and trailer sway initiates, you have every reason to be concerned because the results could be catastrophic. Here are several causes that make your trailer sway and actions you should take to avoid them.
What is a Trailer Sway?
Trailer sway, or "fishtailing," is when a trailer begins to move from side to side when you reach a certain speed while towing a trailer. It is the most common issue many trailer owners face.
While wind is the major problem for RVs, there are still other factors that cause trailer sway. These include towing speed, bow waves that come from passing trucks, bad roads, downhill travel, improper loading, and poor weight distribution.
Trailer sway almost always begins in a sneaky subtle fashion. Then, as the driver notices his RV moving side to side, he will instinctively try to correct it. The sway builds and builds to a point where control of the vehicle quickly comes into question.
At this point you and your family’s safety and even their very lives become a concern.
If you think I’m kidding – do a web search. These crashes are daily experiences. We have a saying,
“Sway is not if - it’s when.”
When most people buy a trailer and hitch for the very first time, they really don’t know what they should be looking for. The type of hitch they’re getting is really just an afterthought because it’s way too easy to assume all models will work just fine without any issues. It’s also easy to assume that all models are alike.
But neither of those assumptions are really the case. And as soon as you get out on the road and start negotiating those very first turns, you hit what should only be a minor road condition, and things quickly start to unravel for them. Maybe a truck passes. Or there’s a little wind. Or the road gets uneven. Or you steer to get around something. Then all of a sudden motion on the trailer picks up, you start swaying all over the road, and you begin to lose control of your rig and more seriously, you and your family are now in grave danger.
The ProPride 3P® Jim Hensley Hitch is the most effective way to eliminate sway and there are no alternatives to it. It is the most advanced of three Jim Hensley hitches ever produced.
Causes of Trailer Sway
1. Insufficient Tongue Weight
One of the most common causes of trailer sway, particularly for travel trailers, is insufficient tongue weight. The proper tongue weight for a trailer with a ball-mounted hitch is 10% to 15% of the trailer's Gross Towing Weight. If you exceed the tongue weight, it could be detrimental to the tow vehicle. The opposite can also be a problem if the weight is distributed too much to the rear of the trailer which can create lift on the ball.
Without sufficient tongue weight, this can happen:
2. Towing Speed
Typical highway speeds have become much greater over the last 50 years. The speed at which you decide to tow your trailer may be the single greatest factor in controlling trailer sway. Unfortunately, tests show that any speeds greater than 45mph tend to cause trailer sway with a majority of trailers. With traffic traveling at much greater freeway speeds it isn't safe, and most of the time illegal, to travel below 45mph to control trailer sway.
3. High winds
Winds blowing perpendicular against the side of a towed trailer push the trailer and pivot it on the hitch ball creating a tow angle. The greater the surface area of the trailer, the greater the force will be at any given wind velocity. Towing in high winds is never a good idea and should be done cautiously if necessary.
4. Gusting Winds
Winds can gust and increase in velocity due to weather. Gusting winds can also be blocked by trees or overpasses, only to be felt once you have passed the treeline or the wind obstruction. Your trailer goes from a relative low side force to much higher side force that pivots the trailer on the hitch ball and creates a tow angle.
5. Bow waves
A bow wave is a wind produced by a large semi-truck, box truck or van pushing its way through the air on the highway. This wind travels around the truck and down the sides creating a wind disturbance in the adjacent lanes. This wind disturbance creates a sudden high to low pressure in the air traveling down the side of your trailer. The bow wave, as with the other wind disturbances, creates a tow angle by pushing the trailer and pivoting it on the hitch ball. The bow wave produces a "sucking" feeling that feels like the entire tow rig is being pulled into the other lane.
6. Uneven road surfaces
With any type of travel across this great country you'll realize there are quite a few roads that need work. Potholes, road cracks and other road imperfections, these uneven, poor roads can make a trailer become unbalanced and cause it to pivot on the hitch ball creating a tow angle.
7. Downhill travel
Towing downhill can allow your trailer to roll faster than the tow vehicle. The tow vehicle is geared to slow down when you let your foot off the accelerator. However, trailers are not equipped with this feature. When the trailer is traveling at a higher rate of speed than the tow vehicle it can begin to yaw.
8. Poor trailer design
The fact is that some trailers are designed better for towing than others. Trailer design includes a lot of different variables that need to be addressed to properly balance the trailer for towing. Trailer designers can have a hard time determining what the optimal layout of the trailer should be because customers will use the trailer in a variety of ways.
9. Improper Loading
Trailers are very sensitive to where you place your loaded cargo. Your black and gray water tanks, your supplies, your clothing and anything else you carry with you will change the weight of the trailer and how that weight is distributed throughout your towed combination.
10. Poor Weight Distribution Hitch Adjustment
When a weight distribution hitch is not adjusted properly it can cause your trailer to have either too much tongue weight or not enough tongue weight with inducing sway. Check out the lego demonstration to understand.
Actions to avoid Trailer Sway
| 1. Distribute the weight correctly Properly distribute the weight and there will be no trailer sway. |
| 2. Slow down The most frequent cause of trailer sway is probably exceeding the posted speed limit. Plan your journey at a safe speed, or give yourself enough time to reach your destination without incident. |
| 3. Avoid making any sudden steering changes. |
| 4. Pump your trailer brakes Make sure that you will always be able to react on time. |
| 5. Get a 5th wheel It does convert your rig to pivot above the rear axle. |
| 6. Be cautious of high winds and passing trucks It’s a good idea to keep an eye on the weather and your speed when towing. |
You may think these actions will avoid trailer sway, but no. These actions can only reduce trailer sway but will not stop it. Friction-based hitches only reduce sway as well. These are just trailer sway myths. It will still happen to you.
There’s just one important issue you’re going to want to keep in mind...
Even when people know these tips, they still don’t always
do the right thing at the right time,
because they aren’t properly trained.
Some say, “I have been towing for years and never had a problem.” Even an experienced driver can be caught off guard by trailer sway, which can be dangerous if not managed appropriately.
People need to realize that trailer swaying can get out of hand fast, and the best way to avoid it is not to manage it but eliminate it.
Enjoy towing safely
Many hitch designs make the claim that friction based solutions can reduce sway. Although it's true, it is not as safe as the Jim Hensley Hitch. Here’s the problem every conventional trailer hitch on the market is manufactured to only pivot at one single point. That would be where the hitch ball sits behind the rear axle of the tow vehicle. This allows the trailer to pivot directly on the ball in a basic side-to-side motion.
A ball hitch ensures the very fact that
SWAY IS INEVITABLE.
Theoretically, this should be fine since inexpensive band aide type conventional sway control hitches apply their own level of opposing friction any time outside forces are fed into the hitch.
But theory and reality are two different things.
These types of hitches are mildly effective only when you’re towing something extremely light. When towing something that weighs TWO AND A HALF TONS, you really can’t expect a conventional hitch to generate enough friction on its own to properly offset the force and keep the trailer centered.
Instead, the weight usually creates too much leverage on the tow vehicle, so the driver ends up over-correcting and starts fishtailing back and forth, desperately trying to balance out that pull on the trailer. The driver must stop it while it’s happening or it’s only a matter of time before losing control and jackknifing ...or worse, possibly even flipping over.
Fortunately, there is a solution. With ProPride 3P® Jim Hensley Hitch trailer sway can never happen. Watch the video below.
With ProPride 3P® Jim Hensley Hitch trailer sway can never happen. Watch the video below.
As you can see, the trailer shifted a little bit without having any impact on the towing vehicle. The vehicle remained stable, and the driver didn't lose control of it.
This is how the ProPride 3P® Jim Hensley Hitch works. Its 3P technology feature, which stands for Pivot Point Projection, works completely different. Because we don't need frictional forces to stop the ball from rotating, the tow is incredibly stable. Watch this lab demonstration:
In fact, most customers of the ProPride 3P® Jim Hensley hitch who had previously used a friction based solution trailer sway hitches have noticed differences in weight distribution and trailer sway. They have all wished that they had started with a solution that solves the issue, like the most advanced ProPride 3P® Jim Hensley Hitch.
Got questions? Email us at info@propridehitch.com or call us at (800) 960-4767.
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