Tag axle for truck camper rigs

[noteven]

Tag axle article

Code 13 Roll the Weight Police

edit - quoted from the article:

"In 2017, after several people showed interest in purchasing our unit, I decided to design a tag axle to sell. We faced two initial challenges. Number one was to submit a “Request for Interpretation” to DOT/NHTSA. That process took 18 months, moved through NHTSA Chief Crash Avoidance Office to Chief Counsel and resulted in a favorable interpretation of the design. NHTSA, Chief Counsel, determined that the unit would be considered a trailer not a tag axle and would carry its own GVWR. The designation was as a Weight Distribution Truck Camper Trailer (WDTCT) requiring a VIN number, lights and brakes."

[Hemi_Joel]

here is a copy and paste of the review:
Just finished tweaking my new WDTT. Hooked up my boat and I am impressed.

Prior to adding the WDTT with full fuel and 25 gallons of water in my 1172 on a 2017 Ram 3500 4X4 Diesel truck my front axle was 5040(6000 axle), rear axle 9660 (9760 axle) GVW 14700 (14000 GVW) so 700 pounds over. I usually tow a boat with 300 pounds of tongue weight which puts me around 15000 somewhat un comfortable and using a 48" hitch extension I was pushing the limits on this truck.

So, I would like to announce my findings IT WORKS!!!!!

Front axle: 5280

Rear axle: 8700

GVW: 13980

Tag axle: 960

With my boat hooked up:

Front axle: 5220

Rear axle: 8720

GVW: 13940

Tag axle: 1260

Boat trailer axle: 3060

I have only towed the boat to and from the scales but it seems to tow better, time will tell when I head off to go fishing!

What is really great is Roy has gone to effort to work with the National Highway Traffic Safety Administration to get this identified as a trailer so it adds up to another 2000 pounds CGVW and as you can see it has allowed me to get under all. the door sticker weights of my truck

I've included some pictures, as Roy will explain every truck and camper are different, the WDTT has 3 points it attaches to the truck, although it can be only attached at trucks receiver. The Ram hitch make a upward curve so you cannot attach to the hitch tube with the outboard attach points I believe the Ford and GM hitch tube extend out far enough that you can clamp or bolt to the hitch.

I fabricated mounts from my bumper attach points.

Also, because of my camper and truck combination I need to have a lower attach point for a receiver hitch to to a trailer.

These are the brackets I fabricated up

A3910C9D-9C19-480D-B6B1-13ED406369F3_1_201_a

You can see how the attach points worked out for me

78AABA6C-9406-4B81-92AA-47B131651BB8_1_201_a

The reason for the narrower axle than WDTT standard width is the step and the sewer drain on the 1172 in this picture you can see the drain to the left of the tire

12BB4755-4F04-4447-8150-C442EBC3E087_1_201_a

Here is the tire and step clearance

134A1118-C57D-4C8B-9387-F794587EF8F8_1_201_a

The tube above my hitch is where the "normal" hitch extension would attach. I believe between the different distances from the truck bed and the truck receiver hitch and the camper drop down from the truck bed would this may not be required on other set ups

ADB6020C-FD6A-4519-9E23-C23228A98A95_1_201_a

As you can see here without the camper on the WDTT tires don't touch the ground

B56499E8-6E77-443B-B7E5-46964FD1649D_1_201_a

This is just a over head view of my set up

3130F258-8F75-43D2-995B-2A0ADD5C0C5B_1_201_a

A look with camper on..

A1869B11-B62F-4855-99F1-D9632F34403C_1_201_aI truly believe that Roy has a really good product.

2018 1172

2017 Ram 3500 4X4 6.7 DRW

Battle Born Battery

Victron 712

tag-trailer.com

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A3910C9D-9C19-480D-B6B1-13ED406369F3_1_201_a78AABA6C-9406-4B81-92AA-47B131651BB8_1_201_a12BB4755-4F04-4447-8150-C442EBC3E087_1_201_a134A1118-C57D-4C8B-9387-F794587EF8F8_1_201_aADB6020C-FD6A-4519-9E23-C23228A98A95_1_201_a512D61D1-9260-40C7-A543-CF37B4340265_1_201_aB56499E8-6E77-443B-B7E5-46964FD1649D_1_201_a3130F258-8F75-43D2-995B-2A0ADD5C0C5B_1_201_aA1869B11-B62F-4855-99F1-D9632F34403C_1_201_a

[burningman]

stevenal wrote:


Note that tandem axles are placed right next to each other, and the tire sizes are equivalent. These are widely separated from the rear axle and so small there's little flex in the rubber to allow the side movement.

You can see how tire flex helps here.

No they aren’t. Big truck tandem spacing is about 5 or 6 feet, and trailers often have over 10 foot tandem axle spacing, to take advantage of bridge law formulas.
A lot of tire scrubbing happens. It’s just cheaper and lighter and simpler than making them all articulate.

[NRALIFR]

Gotta be a member to see that, unfortunately.

:):)

[mellow]

Someone posted a real life user review of this over on lance owners: https://community.lanceowners.org/topic/pack-enterprises-weight-distribution-tag-trailer-wdtt

Interesting setup.

[HMS_Beagle]

It's like Frederick Brooks mythical man-month (if one man can write a software program in a year, then 52 can write the same one in a week). Nevertheless, that is how commercial products get tested. If you are Ford, you do not take 4 trucks and test them for 250,000 miles each to get a million miles of testing. You take a hundred trucks and run them each 10,000 miles.

In this case, if someone runs one of those tags across the country - 3000 miles - and doesn't have any issues with it, then I'd say that is a decent test. If I were buying one, my attitude would be the same as with all aftermarket equipment - it probably isn't going to be perfect, you are hoping that the flaws you are sure to find will not be terminal.

[StirCrazy]

HMS Beagle wrote:
I'm not going to argue it is a good idea for everyone, but the claim is they have over 100,000 miles of installed experience. With that existence proof, dismissing it out of hand without more knowledge than you read in an on-line article is probably premature.

I agree with you aside from the one point of giving validity to the "100000miles of installed experiance" I hate statments like this as they are designed to do nothing but misslead people. so did he install 20 units? that would mean on average there is only 5000 miles applied to the unit, 10 units would mean 10,000 average miles, if he did 50 units then an average of 2000 miles.

its like a group of 10 mechanics who worksed in different places for 10 years, get togeather and form there own company and start saying we have 100 years of experance.... no you don't you have 10 years of experiance 10 times......

Steve

[Hemi_Joel]

Many of the big campers have a center of gravity behind the rear axle. No tires, springs, or bigger truck will cure the effects of that. Maybe this thing would.

[noteven]

So he sneaked a bad dangerous idea past these people?




"In 2017, after several people showed interest in purchasing our unit, I decided to design a tag axle to sell. We faced two initial challenges. Number one was to submit a “Request for Interpretation” to DOT/NHTSA. That process took 18 months, moved through NHTSA Chief Crash Avoidance Office to Chief Counsel and resulted in a favorable interpretation of the design. NHTSA, Chief Counsel, determined that the unit would be considered a trailer not a tag axle and would carry its own GVWR. The designation was as a Weight Distribution Truck Camper Trailer (WDTCT) requiring a VIN number, lights and brakes."

[HMS_Beagle]

I'm not going to argue it is a good idea for everyone, but the claim is they have over 100,000 miles of installed experience. With that existence proof, dismissing it out of hand without more knowledge than you read in an on-line article is probably premature. Every one of the alternatives you suggest is far more expensive than this, with the exception of 19.5 which solve only a tire capacity problem. He is not the first to do it, there have been campers sold with tag axles in the past and there are or have been other vendors for pickup truck tags. As far as I know, no deaths resulted from them. Comparing to jumping off a bridge is fallacious.

I believe the concept is workable, but probably a good solution only for a narrow set of circumstances. The reliability and safety depend a lot on details which I don't have and weren't illuminated in the article.

[HMS_Beagle]

Grit dog wrote:
This thing isn’t tire scrub like a tandem trailer. The pivot point is the rear axle of the truck. In a tight turn, it will partly drag the wheels sideways. Under an unknown load.
This looks like something I’d fab up to redneck a heavy load a short distance.

The pivot point isn't the rear axle (unless you have 90 degrees of front wheel cut). Most full size pickups have a turning radius of ~50', so if the tag is 6' behind the rear axle your scrub angle is about 16 degrees. Not great, but isn't going to kill the tires unless you do circles all day long.

Lots of speculation about something that no one posting yet has seen or used. It would be more informative to hear from someone who has used one. I haven't, it doesn't look like the best solution for most people but might be pretty good for some.

[Grit_dog]

This thing isn’t tire scrub like a tandem trailer. The pivot point is the rear axle of the truck. In a tight turn, it will partly drag the wheels sideways. Under an unknown load.
This looks like something I’d fab up to redneck a heavy load a short distance.

[StirCrazy]

Kayteg1 wrote:
I don't think tire scrub is big issue.
I park my boat on T-shaped driveway and at some point I had 2-axle trailer pushed at close to 90 degree. Now I have pretty clear rubber scrubbing marks on my driveway, but I am not worry about tire life.
Boat trailer tires in 99% of occasion are replaced due to age, not wear.

I don't think it is as big of an issue as some are making it out but it is definatly more of an issue than a pull behind two axel trailer. because they are conected to the truck with no pivioting ability every time you turn it will force sideways pressure onto thoes tires so the lateral load may not be as hard as jack knifing a double axel trailer into a camp spot, but it will be way more often.

what I would be concerned about more is if it has some sort of verticle movment weather it be spring loaded or hydraulic.. I dont go 4x4ing but I do take some uneven roads to get into some sites and that would be a lot of stress on the unit if it was suporting the whole back end of the truck through a dip.

Steve

[Kayteg1]

I don't think tire scrub is big issue.
I park my boat on T-shaped driveway and at some point I had 2-axle trailer pushed at close to 90 degree. Now I have pretty clear rubber scrubbing marks on my driveway, but I am not worry about tire life.
Boat trailer tires in 99% of occasion are replaced due to age, not wear.

[StirCrazy]

jimh425 wrote:


Funny that some of you compare this poor design supported by the hitch to axles attached to the frame like when the axles are fairly close together like on a dual/triple axle trailer.

its not supported by the hitch, it has two frame mounts and and a hitch extension so it is actualy frame mounted.

having said that, yes the tires will be subjected to a higher amount of scrub than a trailer set up, but it would be a reasonable solution to some one who uses the camper once and a while, or if there camper is ok on there truck but if they want to tow there boat they need a bit more... we can think of ways that it wont work all day, but I can also think of a fw situations it would be good.

Steve