If you pull an empty (or nearly empty) utility trailer, you probably know the feeling of utility trailer bounce. It is that bumpy jolting extra bouncing you feel in the tow vehicle as you drive. Sometimes it feels like the trailer is just bouncing away behind you, yet it is not, but really it is.
The feeling is so common, some people just expect it as a normal matter of towing. Yet, it does not need to be that way – at least it does not need to be as severe as many people are just used to. Let’s take a look at the causes and possible solutions to make the towing experience a little less “Bouncy”.
What Causes Utility Trailer Bounce?
The simple answer is the suspension is too stiff for the load. There are other parts to it, like load balance and the axle position, but we will get to those in a minute. Basically utility trailer bounce happens when there is not enough compliance in the suspension system for the current load and road conditions.
If your trailer is rated at 3500#, and you are pulling it empty (maybe 550# trailer weight), then the suspension is not going to compress much over a bump. Instead, it bounces – and sometimes keeps bouncing because full tires are a bit like basketballs on the ends of the axle.
Remember, a trailer suspension is a system of components that includes both the springs (or rubber with torsion axles), and the tires. The springs are just one compliant piece in the system. The tires are another.
Some people say: But I have a torsion axle, which is supposed to be softer. Why does the utility trailer still bounce?
Yes, torsion axles do tend to ride a little smoother, but when the trailer does not have a load, the suspension is stiff – even with a torsion axle. And, there are many other trailer axle types.
Amplification
To make matters worse, depending on trailer length and where the axle is, when the car goes up and down over a bump, that teeters the trailer like a teeter-totter. The mass of the trailer frame wants to keep moving even as the shock absorbers on the car are trying to smooth things out. Then, the trailer tires go over the bump and the mass of the frame is excited again. All of this jostling makes pulling the trailer somewhat annoying, if not disconcerting. (Read the details in “What Is The Right Trailer Tongue Length?“)
Pulling a trailer in a truck with a stiff suspension also amplifies the effect. And, if the trailer is quite heavy and/or long, that makes things worse too. Finally, the smaller the tow vehicle (compared to the trailer), then the greater the effect. (Makes sense, a heavier trailer has more mass when it bounces, so it shakes the car.)
So, is there a way to fix it? Can we make it go away? What about shock absorbers for the trailer?
Utility Trailer Bounce Solutions
The focus here is on utility trailers because they often pull empty, then full, then empty. They also have a large difference in weight from empty to full, which is why we call it “utility trailer bounce”. It happens with other trailers too, and what you are feeling is not only bounce, but all the movements of the trailer. Yet, the bounce part is the topic of this page.
Can we fix it? The honest answer is NO. BUT, you CAN calm it down considerably!
Here are several areas that affect bounce, and things you can do to reduce the bounce – utility trailer bounce, or other types of trailers too. These are most effective on single axle trailers, but do help for multiple axles.
Tire Pressure
The easiest way to reduce utility trailer bounce is to adjust tire pressure. By lowering pressure, the tires act more like a partially filled basketball and they bounce less. How much pressure? That depends on trailer weight, tire size, and tire type. See (trailer tires or automotive tires) for more. In general, for an empty utility trailer, you can run half the normal pressure.
For one trailer, I had 225-70 R15 automotive tires, normal pressure was 35psi. The trailer capacity is 3500 lbs, but the empty weight is 600 lbs. When empty I ran a pretty low 12-15 psi which smoothed things out superbly. Automotive tires usually require a little more pressure because they have softer side walls. Radials especially. Just make sure you do not exceed the tire pressure rating.
Please do not take my word on it, experiment with your trailer. Try reducing by 10psi, then go down in 5 psi increments until the bounce is acceptable. It will not go away completely, but the effect of lower tire pressure will change the bouncing and jostling effect a lot. Basically, we are asking the tires to take the suspension impact instead of the stiff springs or torsion rods.
With very low pressures you run several risks of tire damage, so do not go too low. It will not really wear the tire more quickly when the trailer is empty, so that is not a problem, but a big bump can cause other trouble. Also, if you are taking the trailer to pick up a big load, make sure you also carry an auxiliary tank or pump – because you DO NOT want to haul a full load with this kind of low tire pressure.
To make it easy, use this cool tool for inflating / deflating the trailer tires.
Other Options
There are rubber inserts on some shackles which will dampen some of the bouncing. That is worth a try, but they can be somewhat expensive, and limited in the effect they have. (It depends on the type. There are many styles, and some are better for utility trailer bounce than others.)
If it is practical, add a longer tongue or set the axles back a little. Having a poor axle placement will certainly contribute to less-that-stellar towing. These ideas will also reduce the bouncing you feel in the tow vehicle, because it increases the tongue weight. (Which can be good and bad.)
Torsion axles are a little better for bouncing than leaf springs, because rubber has a natural hysteresis. However, running empty will not deflect the rubber in the torsion much (if any), so there is not much of an effect. (Again, this is the empty trailer condition.)
Also, tandem axles reduce utility trailer bounce some because they interact with each other to mitigate some of it. While it is an option for some, it does not work for all.
Finally, if you want to replace the whole suspension (or if you are building a new trailer), there are options. One other axle mounting style is this Walking Beam Suspension which will do a lot for bounce because the wheels counteract the bumps with each other. The Timbren Silent Ride is also a walking beam product that can help.
Final Thoughts
Utility trailer bounce is a pretty common problem. While it is not a destructive or breakage kind of problem, it is certainly an annoyance when you are driving.
If this is a concern for you, the easiest thing to try is tire pressure reduction. The next most easy is weight distribution. With a utility trailer shifting weight around as a simulation of moving the axle is usually pretty easy. Just move the heavier items you carry to the front of the trailer. Things like the spare tire, for instance. Just having some added front ballast can go a lot way to calming a bouncing trailer.
Please note, that changing weight distribution forward changes tongue weight. In this case, we are talking about a nearly empty trailer, so the added tongue weight should not matter (like moving the spare tire to the tongue, for instance). However, this is not a good approach if you are already tongue heavy. Check your vehicle specifications to know the proper tongue weights, then don’t exceed them.
Next most easy – but does require some cost – is adding rubber into the system. Rubber in the axle attachment, and/or rubber in the hitch. They make such parts, but they are not so cheap. The rubber, if properly applied, will damp out some of the most obnoxious bumps. Basically, it does not solve the utility trailer bounce problem, but it does mitigate the extremes.
Thanks for reading. If you know about other options, please leave a comment below to share with all our readers. Thank you.
Good Luck With ALL Your Towing !!
Next topic: Know the tire codes when choosing trailer tires. Reference charts for Speed Ratings and Load Index included. The article also includes tire recommendations by axle capacity for your trailer.
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