Welcome to our New Look.  Please let us know if anything misbehaves.  Thank You.

Video – Why Do Some Trailers Tow Stable?

The way a trailer tows makes a big difference in the ownership experience.  So, Why do some trailers tow stable, while others do not?  Even a small trailer that does not behave is intimidating on the highway, and a lot of work to tow.  Bigger trailers that waggle are downright dangerous.  (Of course, that does depend on the severity of the waggling.)

On a recent trip, I caught one such small trailer waggling away behind the tow vehicle rolling down the highway.  My wife was a great sport and took this video for you.  It’s a little shaky, but, with the help of YouTube stabilization, not too bad.

Learning From Another Example

Look at the trailer and how it tracks behind the towing vehicle.  For the most part it follows well, but when there is an small interruption — like going around this curve, or a bump, a minor steering correction by the driver, etc., the trailer fishtails just a little.

This vehicle caught my attention when the driver changed lanes and the trailer did a pronounced waggle.  Fortunately for them (unfortunately for the video), the driver did not do that again while we watched.  Nevertheless, you can still see some tail wagging in the video as they round this bend.

For reference, this waggling from side to side is called Yaw — one of the important vehicle attitudes.  Important, but not desirable (except in a purposeful full drift!)

This waggle is actually not that bad.  However, I’ll bet the driver feels some weird steering inputs and probably has to fight it just a little from time to time as they drive.  That said, a little can be a lot if it makes the driving more stressful.

Making Trailers Tow Stable

What makes some trailers tow stable, while others waggle down the road?  We wrote a full article about Trailer Stability, (with related trailer design articles) now posted on our parent site Synthx.com.  It’s a good place to start reading.

For the one in the video, it’s hard to say exactly the cause of the semi-stable behavior just by looking.  However, I will guess it is poor loading.  Probably the center of mass is too far back leaving insufficient tongue weight.  Also, (not in the video) the trailer tongue is a little short, which can amplify loading (and stability) issues.  See the post on setting the right axle position with discussion on loading for more on making trailers tow stable.

Of course, there are likely some other contributing factors.  Look at the weight distribution side to side.  Again, this is not a big deal by itself, but the right side motorcycle is bigger, and probably heavier than the left.  (Note the motorcycle rear tire size.  Typically a bigger tire means more HP, and therefore likely more weight, though these are guesses.)  With all that, I’ll bet if they stop and redistribute the trailer contents for a more centered (side to side) and slightly forward center of mass, then this trailer will be much more stable and enjoyable to tow.  While it would be fun to show them on the spot, I’m sure the intrusion would not be welcome.  Oh well.

I will give them props for securing the load well.  As another driver on the road, I really appreciate it when folks take the time to strap down and secure their loads.  Stuff flying from trailers (or vehicles for that matter) is no fun.  Thank You.

Other Contributors In Making Trailers Tow Stable

Other typical contributors (not shown in the video) include wheels, tires, axles, and alignment.  Those are in a section by themselves below.

Aerodynamics can also play a role especially in highway cross winds.  Large profile trailers can get a push by a wind gust, or even by air flow around a larger vehicle on the highway.  Wheelbase also plays a part.  Longer is usually better — if you get the other contributors right.

Finally, the tow vehicle is important — especially when the trailer size exceeds the tow vehicle size.  The bigger the waggle, the more it takes to control it, so make sure your vehicle is good for it.  The closer the rear wheels are to the hitch point, the better also.

The key in all of this — It’s never just one thing.  The whole system is involved.  Stack the deck in your favor for stability on the road.

When It All Goes Wrong

Stability is more than just a buzz word.  As mentioned above, minor instabilities are mostly just an annoyance that make towing less pleasant.  On the other hand, when we think of it as teetering the balance toward disaster, it has a different light.

The example in this article about safety chains is a stark reminder that all the details matter.  It’s never just one thing, it’s the whole of circumstances and situation.  That’s highlighted even more in this article from several news stories about dangling from a bridge by just one trailer chain.  Though I don’t have proof, I suspect weight stability is one of many contributors in both these accidents.  It’s really no joke.  Perhaps both could have been avoided a with setup so the trailers tow stable.

Don’t Forget Wheels And Tires

While it does not appear to be an issue with this trailer, one other factor to help trailers tow stable is the wheels and tires.  Without going into much detail, here are a couple thoughts.

First, tire pressure makes a difference.  One side low and one side high will make the trailer do weird things when you hit a bump or swerve.  So, make sure the tire pressure is right, and the same on both sides of the trailer.  Tire pressure is also very involved in trailers that bounce.  That’s a different kind of stability.

Second, if a trailer wheel is not balanced, or if one gets damaged, like bent, the trailer will wander — especially at speed.  Have the wheels balanced and inspected once in a while.

Finally, for multi-axle trailers — tandem and triple — make sure the axles are parallel with each other, and perpendicular to the direction of travel.  Straight and square as they like to say.  Misaligned axles will not only cause weird dynamics and the trailers may not tow very stable.  They will also wear out tires fast.

For more about tires, read this about choosing trailer tires, and this about spares.  Enjoy.

1 Comment About “Video – Why Do Some Trailers Tow Stable?”

  1. Dear Mechanical Elements, You didn’t mention the patently obvious in this example – bias-ply tires on the trailer fighting radial-ply tires on the car!! Regards

    Reply

Leave a Comment

We Found These For You . . .

Article
Which Welder To Buy?
I’m looking to build one of your trailers, but I need to know which welder to buy?  What type, and do I…

Read More

Article
Solution! for Air Tools
A simple Solutions! reader submission for easy access and organization of his common Air Tools.  Simple enough to build in an hour, and great…

Read More

Product
6 x 12 Utility Trailer Plans

The 6x12 utility trailer is the most popular of our 6' width trailers.  It's great for business, landscaping projects, ATV's, moving, . . . you name it.  Lots of volume, yet very maneuverable and it tows…

Article
DIY Legacy Tools
Who influenced your creativity and Do-it-Yourself enthusiasm?  Was it your dad?  A shop teacher?  Or a neighbor that was into cool projects?

Read More

Article
Trailer Hitch Safety Chains
Do they accomplish the intended purpose?  Or are trailer safety chains just a legal pain in the rear?

Read More

Article
Steel for the Next DIY Build
This is what the beginning of a new DIY build looks like.  Of course, there’s the planning stages, the design stages and…

Read More

Article
JTP Building A Trailer
We’ve been working with the great folks at Johnson Trailer Parts for a while.  Their business is primarily selling trailer parts, but…

Read More

Product
6x10-Utility-Trailer-Plans

A fantastic utility trailer with a full 10ft+ bed length.  Plans include the base trailer, of course, then a lot of options so you can build it to meet your exact needs.  (Some options are shown…

Article
Twisting Trailer Safety Chains
Should you twist trailer safety chains to make them shorter?  Certainly twisting them reduces the length so they don’t drag the ground. …

Read More

Product
Wider 12 x 32 Tiny House Trailer Plans

If you want a wider, more livable tiny house, consider these 12' wide x 32' tiny home foundation trailer plans.  This is our extra wide, triple axle trailer design specifically for the needs of a Tiny…

Article
Ways to
Have a trailer that you would like to repurpose?  Or a lightweight trailer that needs a little beef?  Is it practical to…

Read More

Article
Clamps and Drills Access and Storage Solution
Storage space is a high priority in my shop.  Maybe in yours too?  It’s not that there is not enough space, it’s…

Read More

Article
Aluminum Weld Adjustments
I’ve heard different opinions, so let’s look again at the Engineering and clear up some facts.  Maybe we can also debunk a…

Read More

Article
Folding Trailer Tongue Finished
Intrigued by the cool potential of saving storage space, increased security, and removal of a shin knocker to step over, this new…

Read More

Product
20ft Tiny House Trailer

Enjoy this sturdy Tiny House Foundation (trailer) to build your own custom home on.  Begin with a solid foundation, which allows confident Tiny House construction, knowing the foundation is secure. These plans are for a 20…

Product
i-Beam Connector Clamp Bracket

The I-Beam Connector Clamp is one of those simple products that, if you have the need, then it is absolutely perfect. For Gantry Crane owners that have one of the Mechanical Elements cranes, this product may…

Article
May Is Build Month - DIY Plans Sale
May, the time of new flowers after April showers, is also the time for building that project you’ve been stewing on over…

Read More

Article
Living Tiny In A Bigger Way
OK, so you want to Live Tiny.  That’s awesome.  What can you do without?  What do you really want to have?  And…

Read More

Product
Mechanical Elements 4x8 Utility Trailer Plans

A 4x8 utility trailer is a great size - perfect for odd jobs or hauling for a motorcycle.  This 3500 lbs capacity is rugged and built to haul a lot of stuff -- yet, the 4ft…

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…

Read More