What Is The Right Trailer Tongue Length?

How long should a trailer tongue be?  Is there a standard or is it totally arbitrary?  Let’s get some answers on this fun trailer tongue length topic.  Except, I need to ask:  How much do you want to know about it?

The stimulation for this post comes from a reader question.  I’ve edited the question for flow.

A Question (Edit) From A Reader

As a thought experiment, let’s imagine an 8′ utility trailer with 4′ tongue.  The axle is positioned so with an even load on the trailer bed, the resulting tongue load is 15%.  (As described in the article “Where Does The Axle Go?“)  Now, if we extend the tongue to 12′, the trailer would look ridiculous, but the tongue load would go down to 7.5% — half.  The center of mass with respect to the axle is the same, so would the second case also tow stable?  (Despite being outside the normal rule of thumb?)  Are there other inherent stability benefits of trailer tongue length?

Before we give an answer, what are your predictions?  My guess is most of you know the answer by gut feel, but might not know how to explain it.  Let’s see.

Trailer Tongue Length Answers

What’s With The Tongue Load And Stability Anyway?

To best explain the effect of trailer tongue length, let’s take the above experiment and play with it a bit.  Let’s take the 8′ trailer with the 4′ tongue described above and move the load in the trailer back so there is Zero load on the tongue.  Perfectly balanced on the axle.

Now, let’s drive down the road.  When your car goes over a bump it pushes the tongue up fast, which throws the load back slightly, which really makes the trailer want to flip back (because the load is now behind the axle and there is inertia with the load pivoting around the axle).  Of course the trailer does not flip back, because you tightened the hitch properly.  Good Job!

Straight Line Trailer Tow
Bump Effect on Trailer Stability

Next, as your car comes down from the bump, the process goes the other way.  The tongue pulls down and the load rotates back to where the tongue has Zero load.  Then the trailer goes over a bump.  The dynamic load switching causes some weird dynamics for the driver that feels like it is “bucking”.  The same, but opposite, is true for a car going into a hole in the road.

On the other hand, if the trailer has the load forward of the axle, the tongue load is always positive, even when there are dynamics at the car moving the tongue up and down.  Experimentally, a tongue load of 10% to 15% of the total trailer (with cargo) works well for dynamics.

Will A Long Tongue Trailer Tow Stable?

Making the trailer tongue length 12′ (as mentioned in the reader question above) does indeed decrease the tongue load (to 7.5%).  How does that affect things?

Let’s think about what will happen when we hook that up to your car and drive over the bump.  Again, think about the trailer setup with perfect balance over the axle, and the tongue has Zero load.  As the car goes up over the bump, the end of the long tongue goes up with it.  However, because the tongue is so long, the trailer itself does not tilt as much, so there is less “bucking” — even though the trailer has the improper loading.  Also, the tongue works as a long lever to move the load up and down, which works to further reduce the effect of buckling.

With proper trailer loading (tongue load around 12%), a longer tongue acts like a damper to the other dynamics at the trailer.  For an obnoxiously long 12′ tongue, from the trailer’s perspective, it makes the bump feel half as high.  That’s part of why we tell people to avoid trailers with really short tongues.

Ridiculously Long Trailer Tongue

Please, don’t take this example as more than an illustration.  A 4′ tongue is long for an 8′ trailer, and a 12′ tongue is ridiculous.  Also, Please note that the above discussion is straight line, 2-dimensional dynamics.  There’s much more to it in real life.

Confounding Effects

Trailer tongue length is not the only effect in play.  There are some confounding effects like the tow vehicle rear overhang, and the overall trailer length.

Tow Vehicle Hitch ExtenderThe distance between the rear wheels of the tow vehicle and the hitch ball, acts in many respects as an amplifier to the tow vehicle motion.  The closer the rear wheels are to the hitch, the more stable it is.  Conversely, making that distance long — especially with the use of a hitch extender — adds to driving instability.  Basically every motion of the tow vehicle is amplified to the trailer.  (That’s true up and down as well as side to side.)

Two examples of hitch extenders are in the images here.  Avoid these if possible.

A longer overall trailer length looks in many respects like extra trailer tongue length.  Think about it as the distance from hitch to trailer wheels — though that’s not totally true because of the distribution of load over a longer trailer.

Crazy long hitch extender
One crazy long hitch extender!  This is asking for trouble.  If this were my vehicle, I’d remove the camper corner jacks, then extend the trailer tongue to come up under the camper end to the vehicle.  Just MHO.

Other Inherent Stability Benefits

In the Article about Trailer Strength (on the Synthesis website), we talk just briefly about trailer tongue length.  A longer-ish tongue — within reason — has nifty advantages.

Turning Radius is compromised with a really short tongue.  The tongue should be long enough for a good turning radius, and to allow clearance when backing.  Short tongues impede back up ability, turning radius and jack-knife susceptibility.  Backing a long trailer is much easier than a short one, and part of that is trailer tongue length.

A longer tongue is nice for extending axle separation (distance from the tow vehicle rear axle to the trailer front axle) for both stability and bounce.

Finally, the loading distribution on the trailer is less sensitive with a longer tongue.  This is a minor effect, and you must always be conscience of the way a trailer is loaded, but having a little less tongue weight with a long tongue is easier to manage.  Basically, the shorter the tongue, the higher the percentage of trailer weight should be on the hitch.  Within the guidelines, of course.

Trailer Tongue Length / Advantages / Disadvantages

Some added Advantages of a long tongue include:  1) Backing advantages of a longer trailer.  2) A longer tongue makes it easier to access the rear of the towing vehicle.  Easier to get cargo or people in and out.

Now for the Disadvantages.  One important disadvantage of a long tongue is Aerodynamics.   The more space there is between the tow vehicle and the trailer, the more turbulence there is, and the more aerodynamic loss.  That means fuel mileage goes down with a longer tongue.  Truly this is a small effect for a small trailer, but a larger trailer (with more frontal area), over a long distance, will make a difference.

Turning radius also changes with a long tongue.  When turning a corner, the trailer always takes a shorter path than the tow vehicle.  The longer the trailer, and the tighter the turn, the more of this effect.  A long tongue means you’ll need to be more aware of hitting curbs as you go around corners.  However, on the practical side, for small changes in tongue length (like 6″) you won’t notice a difference.

Ride level is maintained better with a long tongue because the hitch height has less of an effect on the ride level.

Finally, storage is a disadvantages of a longer tongue.  The tongue takes space and increases the total length of the trailer, so it takes more space to store.  Unless, you do something crazy like make the tongue fold (or shorten with a hinge like this) so the storage space required is drastically reduced.

How Long Should The Tongue Be?

So far we’ve danced all around the issues of trailer tongue length.  We’ve talked about towing stability, turning radius, backing up, and more.  Yet, we have not answered the main question.

Minimum Length of Trailer TongueLet’s start by looking at a minimum.  The tongue should be long enough that the trailer clears the tow vehicle in tightest turns.  Usually that means backing situations.  See the image.  That’s the minimum.

The maximum is up to you.  There is a diminishing return to increasing tongue length, so find your optimum based on the size of the trailer and your balance with the disadvantages.  Many designers make tongues at 30″ to 36″.  I personally think that’s too short.  When the tongue gets to the 40″ to 46″ length, that seems to be the sweet spot.

The blue frame flatbed trailer pictured at the top of this article has a tongue length of 72″.  That is really nice for stability and backing, but it does make the trailer unreasonably long in some circumstances.  That trailer was built with a few experiments in mind, so some of the things on it are not really standard — like the long tongue, the walking beam suspension and the folding tongue.

Summary Answer

Make the tongue longer than the minimum for your vehicle, plus whatever added length you feel fits your situation.  Longer is better for stability, but a pain when it comes to stepping around it and storing it.  Also, a long tongue becomes a long lever, so the longer the tongue, the more strength is required where it connects to the trailer.

Good luck with your projects!

19 thoughts about “What Is The Right Trailer Tongue Length?”

  1. Wow, just the info I was looking for. I have a small 40″ x 48″ bed trailer (HF kit) I’ve “altered” to carry 4′ x 8′ sheets, et al. from the box store and taking refuse to the ‘landfill’ station. I lengthened the tongue for ease of use and stability.
    Storage issue is no problem on 3 acres.
    Thanks for this! It confirmed what I already ‘felt’ from 30+ years of pulling various trailers with various vehicles.
    Now, to build one with an Aluminum frame for the GoldWing…

    Reply
    • How did you extend the tongue?did you buy a new tongue for it.how long is the tongue,I want to do the same thing you have done.thanks

      Reply
      • The trailer was a new build, so I made the tongue to fit my needs. It’s about 6.5′ long so that when I fetch full lengths of steel (24′ sticks), then they balance just in front of the axles centerline. That’s what I needed. The long tongue folds up so the long trailer fits nicely in the garage without a bunch of extra space.

        Reply
        • Hi , quick question, how do you fold the tongue? is this safe, Brill idea for storage but not sure how to go about it? suerly the hinge method weakens the load strenth?

          any pics???

          Reply
          • The hinged tongue works great. See this article and follow the links. The engineering makes this tongue stronger than the tube by itself. Sorry, I’ve been so busy I still have not put the plans together for the website. Maybe I need a kick in the pants to get it done.

  2. Unbelievably well explained. Almost to much information, but it was so clear and simplified I don’t care. I feel like a smarter person now.

    Reply
  3. Fantastic article. The tire tread in the photo below “Confounding Effects” is a bit confusing, perhaps the orientation of the tire to the hitch could be explained. Otherwise, great article. Thank you.

    Reply
    • Interesting point about the tread. That’s the spare tire on the back of the tow vehicle 🙂 Sorry that wasn’t a little more clear.

      Reply
  4. I have built bbq smokers and trailers for 30 plus years. I use 4 inch drop acculube axles. A 3 inch square tube and I raise the coupler 3 inches. I always have a tongue length 5 feet plus. I use a fold up jack because I want to open a tailgate with out having a jack to be in the way. 12 percent tongue weight is a good number. one important concern is the connection of the tongue connection to the trailer. a offset bbq smoker is different from a trailer because of the weight on the rear of fire box is heavy. you can calculate the total weight of the trailer to locate axle placement or as I do support the side members and weigh the tongue. changing a boat trailer to another use has so many problems that I would not even consider it. I am in the process of building a smoker with 2 250 gallon propane tanks back with two fire boxes with a partition between them. they will appear to look like a single fire box, wood storage, under aluminum storage boxes, ss side shelves, tandum axles maybe a vertical smoker. reverse flow with tuning plates.

    Reply
  5. What are the measurements (length and width) of the blue frame flatbed trailer shown at the top of the article? Thanks a lot!

    Reply
  6. Another great article! I bought a used 6.5’x11′ utility trailer, however the tongue length on it is only 26″, which I feel is not safe and its hard to back it up without hitting the towing vehicle.
    If I were to extend the trailer tongue bu about 15″, would that increase the trailer tongue weight? Taking into consideration its now an a-frame, and I would be running about 60″ of new 3×3 1/4″ tubing (roughly 44lb by my calculation). I am currently at exactly 11% tongue weigh so trying to figure out if I would also need to move the axle again.
    Thanks!

    Reply
    • Really good questions. First, a short tongue is a sign of a wimpy trailer. Sorry. Second, if you do lengthen the tongue, I think the beam you are saying is good, so run it straight down the middle to join with a few of the cross members and use the existing A-frame to support it. I would avoid moving the axle, but load the trailer more to the front. Yes, it sounds like the ideal case is to move the axle back, but that’s a ton of work. Good luck.

      Reply
      • Thanks for the quick response! Yes, the previous owner decided to extend the trailer onto the tongue by a foot (it used to be a 6.5’x10′), resulting in a very short tongue. The trailer is very sturdy however. I already moved the axle once as there was too much weight on the tongue due to the extension, so I may just move it again and this time also add buffer plates as you suggested in your other article.
        Thank you so much!

        Reply

19 thoughts about “What Is The Right Trailer Tongue Length?”

  1. Wow, just the info I was looking for. I have a small 40″ x 48″ bed trailer (HF kit) I’ve “altered” to carry 4′ x 8′ sheets, et al. from the box store and taking refuse to the ‘landfill’ station. I lengthened the tongue for ease of use and stability.
    Storage issue is no problem on 3 acres.
    Thanks for this! It confirmed what I already ‘felt’ from 30+ years of pulling various trailers with various vehicles.
    Now, to build one with an Aluminum frame for the GoldWing…

    Reply
    • How did you extend the tongue?did you buy a new tongue for it.how long is the tongue,I want to do the same thing you have done.thanks

      Reply
      • The trailer was a new build, so I made the tongue to fit my needs. It’s about 6.5′ long so that when I fetch full lengths of steel (24′ sticks), then they balance just in front of the axles centerline. That’s what I needed. The long tongue folds up so the long trailer fits nicely in the garage without a bunch of extra space.

        Reply
        • Hi , quick question, how do you fold the tongue? is this safe, Brill idea for storage but not sure how to go about it? suerly the hinge method weakens the load strenth?

          any pics???

          Reply
          • The hinged tongue works great. See this article and follow the links. The engineering makes this tongue stronger than the tube by itself. Sorry, I’ve been so busy I still have not put the plans together for the website. Maybe I need a kick in the pants to get it done.

  2. Unbelievably well explained. Almost to much information, but it was so clear and simplified I don’t care. I feel like a smarter person now.

    Reply
  3. Fantastic article. The tire tread in the photo below “Confounding Effects” is a bit confusing, perhaps the orientation of the tire to the hitch could be explained. Otherwise, great article. Thank you.

    Reply
    • Interesting point about the tread. That’s the spare tire on the back of the tow vehicle 🙂 Sorry that wasn’t a little more clear.

      Reply
  4. I have built bbq smokers and trailers for 30 plus years. I use 4 inch drop acculube axles. A 3 inch square tube and I raise the coupler 3 inches. I always have a tongue length 5 feet plus. I use a fold up jack because I want to open a tailgate with out having a jack to be in the way. 12 percent tongue weight is a good number. one important concern is the connection of the tongue connection to the trailer. a offset bbq smoker is different from a trailer because of the weight on the rear of fire box is heavy. you can calculate the total weight of the trailer to locate axle placement or as I do support the side members and weigh the tongue. changing a boat trailer to another use has so many problems that I would not even consider it. I am in the process of building a smoker with 2 250 gallon propane tanks back with two fire boxes with a partition between them. they will appear to look like a single fire box, wood storage, under aluminum storage boxes, ss side shelves, tandum axles maybe a vertical smoker. reverse flow with tuning plates.

    Reply
  5. What are the measurements (length and width) of the blue frame flatbed trailer shown at the top of the article? Thanks a lot!

    Reply
  6. Another great article! I bought a used 6.5’x11′ utility trailer, however the tongue length on it is only 26″, which I feel is not safe and its hard to back it up without hitting the towing vehicle.
    If I were to extend the trailer tongue bu about 15″, would that increase the trailer tongue weight? Taking into consideration its now an a-frame, and I would be running about 60″ of new 3×3 1/4″ tubing (roughly 44lb by my calculation). I am currently at exactly 11% tongue weigh so trying to figure out if I would also need to move the axle again.
    Thanks!

    Reply
    • Really good questions. First, a short tongue is a sign of a wimpy trailer. Sorry. Second, if you do lengthen the tongue, I think the beam you are saying is good, so run it straight down the middle to join with a few of the cross members and use the existing A-frame to support it. I would avoid moving the axle, but load the trailer more to the front. Yes, it sounds like the ideal case is to move the axle back, but that’s a ton of work. Good luck.

      Reply
      • Thanks for the quick response! Yes, the previous owner decided to extend the trailer onto the tongue by a foot (it used to be a 6.5’x10′), resulting in a very short tongue. The trailer is very sturdy however. I already moved the axle once as there was too much weight on the tongue due to the extension, so I may just move it again and this time also add buffer plates as you suggested in your other article.
        Thank you so much!

        Reply

Leave a Comment

We Found These For You . . .

Article
Walking Beam Trailer Suspension With Twin Torsion Axles
Plans are now available for the Twin Torsion Axle Walking Beam Trailer Suspension.  This was introduced on a build early in 2018, with posts about the trailer including a video of the suspension in action.

Read The Article

Article
Timbren Axle-Less Trailer Suspension
Customer Question:  “What do you think about the Axle-Less trailer suspension?  Is it good?”  Can I use it with the Mechanical Elements trailer plans?  . . .  You ask (actually a few of you are asking) and pointing to

Read The Article

Article
There's More To Just Mounting Trailer Axle Springs
As with many things, there’s a lot more to mounting trailer axle springs than first meets the eye.  Here are 2 tips to make your trailer frame stronger.

Read The Article

Article
Nuts and Bolts Project Fasteners
Ever wonder why fasteners like nuts and bolts are so expensive?  You would think something so standard and manufactured in such high volumes would be cheap, but in most places, they’re actually pretty expensive.  Why?

Read The Article

Product
Heavy Duty Gantry Crane Plans

The big one, actually the big many.  These Gantry Crane Plans include Engineering graphs to choose the beam and legs from 2000 lbs - 6000 lbs lifting capacity.  Free Standing, Large or Small, Wide or Narrow. Build to fit your…

Article
Bent Trailer Tongue
When buying a trailer, how can we decide if it’s well built, or just cheap?  How do you know if it’s strong or weak?  While there are always tale-tale signs, we’ll use this example of a trailer with a bent…

Read The Article

Article
What Tires For My Trailer?
There are a million tires out there with a ton of classifications and designations.  What tires do I choose for my trailer?  That is not a silly question at all.

Read The Article

Product
5x8 Trailer Plans, 3500# Capacity

Start building your own utility trailer with these 5x8 Trailer Plans.  Blueprints are fully engineered and include options for various needs.  These plans are a perfect map for a great project.

Article
What Are Your Essential Tools
We’ve been asked many times about “What are the most essential tools for your shop?” Well, that’s a hard question, because frustration and wailing are the result when the right tools are not available.

Read The Article

Article
Gantry Crane Failure Modes
In the debate about Steel or Aluminum for beams of trailer frames and gantry cranes, there is one piece we hear less about.  An important part of the equation, for sure, is the property of Elasticity . . . .…

Read The Article

Article
Spiraling the DIY Project Plans Back Online
January 7, 2016.  Mechanical Elements is back online with a new look, a new logo, new functionality, and a better shopping experience. — With — an expanded offering of the Same Great DIY Project Plans and so much more.

Read The Article

Article
20ft Deck Tiny House Foundation Trailer Plans
There’s an old song comparing the wise man and the foolish man.  It might just be talking about a tiny house foundation!  Goes something like this:

Read The Article

Article
Build it with Torsion Axle Trailer Plans
New Product Announcement:  The Mechanical Elements line of DIY Trailer Blueprints has just expanded with some new sizes for Torsion Axle Trailer Plans.  You ask, then we work to deliver.

Read The Article

Article
How To Weigh A Trailer
Do you need to weigh something really heavy but don’t have access to an industrial scale?  How can I weigh heavy things — like a trailer frame — without a special super heavy duty scale?

Read The Article

Article
Low & Lean Trailer Suspension
A unique trailer suspension offering a low profile, tuning possibilities, and more. By design, the concept offers complete tandem axle load sharing via a common coil spring which is a big plus. Though different than a torsion axle suspension, this…

Read The Article

Article
Saved by Trailer Chain
If you ever doubt the sanity of safety chains, then see this example of where a single trailer chain literally saved lives.  The story is amazing from all angles –

Read The Article

Article
DIY Drilling Steel
Need a hole?  Many of our plans require drilled holes, so here are some Tips about drilling in metal, like steel, as well as in wood, and other materials.

Read The Article

Article
Gussets At Beam Intersections On A Trailer Frame
I have a great trailer, but it feels a bit flexy, maybe even rickety . . . How can I strengthen a trailer frame?  How can I stiffen it?

Read The Article

Product
Canned Food Storage Center

A unique food storage center to hold canned food in a FIFO (First In / First Out) rotation.  The unit sits against a wall so it can store cans anywhere with minimal encroachment into the room.

Article
Overslung or Underslung Trailer Springs
Because you asked . . . What are the advantages of Overslung – or – Underslung trailer springs?  Let’s discuss it.  The concepts are pretty easy to see with some good graphics.

Read The Article

Leave a Comment