How To Stop Utility Trailer Bounce

If you pull an empty (or nearly empty) utility trailer, you probably know the feeling of utility trailer bounce.  It’s 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’s not, but really it is.

What Causes Trailer Bounce?

Bounce Like A BallThe 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’ll get to those in a minute.  Basically utility trailer bounce happens when there is not enough compliance in the system for the current load.

If your trailer is rated at 3500#, and you’re pulling it empty (maybe 500# 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 like basketballs on the ends of the axle.

Remember, a trailer suspension is a system that includes both the springs (or rubber with torsion axles) and the tires.

Amplification

To make matters worse, depending on trailer length and where the axle is placed, 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), the greater the effect.

So, is there a way to fix it?  Can we make it go away?

Utility Trailer Bounce Solutions

The focus here is on utility trailers because they are often pulled empty, then full, then empty.  They also have a large difference in load from empty to full, so it’s often called “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.  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!

Tire Pressure

Reduce Tire Pressure To Reduce Tire BounceThe 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 (trailer tires or automotive tires).   In general, for an empty utility trailer, you can run half the normal pressure.

For one trailer I had with 225-70 R15 automotive tires, normal pressure was 35psi.  Trailer capacity is 3500#, but empty weight is 600 lbs.  When empty I ran 12-15 psi which smoothed things out superbly.  Automotive tires usually require a little more pressure because they have softer side walls.  Radials especially.

Please don’t 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 won’t go away completely, but it will change a lot.

With very low pressures you run several risks of tire damage, so don’t go too low.  It won’t wear the tire more quickly when the trailer is empty, so that’s not a problem, but a big bump can cause other trouble.  Also, if you’re taking the trailer to pick up a big load, make sure you also carry an auxiliary tank or pump — because you DON’T want to haul a load with low tire pressure.

Use this cool tool for inflating / deflating the trailer tires.

Other Options

There are some rubber inserts on some shackles that dampen some of the bouncing.  They can be expensive, and limited in the effect they have.

If it’s practical, add a longer tongue or set the axles back some.  These also reduce the bouncing you feel in the tow vehicle.

Torsion axles are a little better for bouncing than leaf springs, because rubber has a natural hysteresis.  However, running empty you don’t deflect the torsion much (if any), so there is not much of an effect.

Also, tandem axles reduce bouncing some because they interact with each other to mitigate some of it.  While it’s an option for some, it doesn’t work for all.  Finally, there are other axle mounting styles like this Walking Beam Suspension that do a lot for bounce because the wheels counter each other.

Thanks for reading.  If you know other options, please leave a comment below to share with all our readers.  Thank you.

Good Luck With ALL Your Towing !!

Comments

Subscribe
Notify of
22 Comments
Inline Feedbacks
View All Comments

We Found These For You . . .

Product
Up to 50 Ton Hydraulic Press

Do-It-Yourself Shop Press Plans designed for super high capacity, like 20-50 Ton with a Hydraulic ram or Jack.  Choose these plans for times where perpendicularity and parallelism are important.

Article
Makeshift DIY Truck and Trailer
The coolest thing I saw last week was this guy with a very creative DIY approach to a pack trailer — and, of course, his tow vehicle!

Read The Article

Article
Wire Routing and Covering for Trailer Tandem Axle Brakes
It all rides on the trailer axles, so get them right.  Here are some common technologies (and misnomers) for tandem axles and other multi-axle trailers.

Read The Article

Article
A Scary Trailer Along The Road
When things get weird, we all want to see them. While it's fun to laugh (or be shocked) by yourself, it's even more fun to share with friends. If you see rattle-trap trailers on the road, snap a shot or…

Read The Article

Article
Trailer Wiring For Breakaway Kit
What in the world is a Trailer Breakaway Kit?  If you pull a “larger-ish” trailer, you should definitely know, because it’s a legal requirement in many jurisdictions.

Read The Article

Article
More Trailer Plans for Torsion Axles
More New Product Announcements:  The Mechanical Elements line of DIY Trailer Blueprints has just expanded – AGAIN – with more trailer plans for torsion axles.  These new trailer plans fill

Read The Article

Article
Custom Trailer Design
Sometimes looking for the right plans for the trailer you need is a needle in a haystack.  Every site has something, but not exact.  What’s next?  When you really need a particular trailer that others don’t offer,

Read The Article

Article
Cost and DIY Project Economics
“I want to build a new trailer.”  That’s an awesome thing to say, and it’s even better to do.  Yet, many such adventures don’t launch because of project economics?  What does it cost to build? 

Read The Article

Article
Trailer With Attitude
When we think about airplanes flying, or boats sailing, it’s easy to imagine how they move.  An airplane rolls some as it banks into a turn.  A boat pitches up and down with the waves.  So, how do these factors…

Read The Article

Product
i-Beam Connector Clamp Bracket

A simple, mechanical, I-Beam connector clamp made from common materials as a solution for anchor positioning, and to enhance flexibility with a Gantry Crane.  Matches I-Beam flange angles.  Free Plans.