Tongue Weight Major Concerns?

DukeHewett

In researching recommended tongue weights, I'm finding the recommendations within the margins of 10% to 20% of the trailer weight.  Those recommendations seem to be based upon the "tow ability", or tracking.   How much concern should there be in over-stressing the trailers "A" frame if one overloads the tongue weight.   Have the few cracked frames we've seen on some T@B's perhaps been the result of overloading the tongue, especially on bumpy roads where the load can increase substantially?   Has anyone loaded the tongue weight to 25% or so and found bad tracking or stress cracks on the frame? 

Denny16

A an increased tongue weight (Edit up to around 20/25% of total weight on a TaB) will not decrease stability.  Depending on the trailer design you van go to 30% of total trailer weight on the tongue.  As for frame stress, the trailer needs to be designed for the heavier loads.  Not sure I would want to push a TaB tongue weight past 20% on a 320, due to its two part frame design with the joint in the front.

Cheers 

FishDoctor

I do not purport to be an expert, but based on my reading I think the bigger concern with tongue weight is if the percentage of total trailer weight gets too low (<10%). That is more likely to result in major sway oscillations and loss of tracking control because the trailer is excessively back-heavy. Higher percentages of tongue weight are probably more of a concern in terms of the capabilities of the tow vehicle and hitch to handle the stresses. As long as the tongue weight falls under the rated maximum specs for the vehicle and hitch (with a margin of error allowed for safety), it probably won't make the tracking of the trailer get wacky. At least that is my understanding.

I don't know about the potential for stress cracks on the trailer frame.

Grumpy_G

Basic physics apply so it also depends on where weight is added. If you're thinking of mounting something to the tongue in front of the storage tub then most of the weight is carried by the tow vehicle. If the weight is added in the tub or besides it the tow vehicle carries less of the weight and more of it goes onto the axle which increases stress in the potential crack area. 

What are you trying to do ? 

Viajero

Denny16 said:

A an increased tongue weight will not decrease stability, but the opposite.  Depending on the trailer design you van go to 30% of total trailer weight on the tongue.  As for frame stress, the trailer needs to be designed for the heavier loads.  Not sure I would want to push a TaB tongue weight, due to its two part frame design with the joint in the front.

Cheers 

Totally disagree. This video is a good primer for towing characteristics and loading. Too heavy of a tounge is just as bad as too light of a tongue. 

For what it’s worth European engineers are taught to design trailers with hitch weights of 4 to 9 percent. 

https://youtu.be/JeEEC5eVNCk

,

DukeHewett

Grumpy_G said:

Basic physics apply so it also depends on where weight is added. If you're thinking of mounting something to the tongue in front of the storage tub then most of the weight is carried by the tow vehicle. If the weight is added in the tub or besides it the tow vehicle carries less of the weight and more of it goes onto the axle which increases stress in the potential crack area. 

What are you trying to do ? 

Thanks Grumpy G!
I hadn't considered where the weight is added  between the axle and the ball hitch is a major factor.  I have less concern now about loading the Jack-It bike rack with bikes since the load will be significantly forward of the tub, loaded at the jack-handle location, just short of the coupler.  Therefor the tow vehicle (Toyota Tacoma 4WD) will assume a good portion of the load.  

Denny16

The video example shifted 2/3rds of the trailer weight to the front tongue area, which I agree is unstable also.  You can have too much weight.  I mentioned (qualified) my original comment that adding only up to 30% of the total trailer weight forward on the tongue weight would be as stable as 15% of the load which is ideal for a travel trailer.  You need a minimum of 10%, but the max is around 25/30% depending on the trailer design.  Boat trailers are typically loaded with 30% of the load on the tongue.  

Cheers 

ChanW

Thanks for that video @Viajero. I learned a few things from it.

I hadn't expected that spreading the load front and rear would be a problem. I'll adjust my packing strategy, I think.

pthomas745

The video with the European trailers/vehicles are not applicable in any way for vehicles in the USA. Everything about European towing and safety design standards is completely different from the US safety and design standards.  Cars are different, tow hitches are different, road speeds are different, etc. So, take that video with a big grain of European salt.

Edit: the video is from Australia, and concerns Australian standards, not European!

Every once in a while someone shows up in various forums towing a Tab with a much too small vehicle, and when confronted, the claim is "They tow with it in Europe, so why not?"

Here are the threads:

https://www.google.com/search?q=european+towing+standards+site:tab-rv.vanillacommunity.com&amp;client=firefox-b-1-d&amp;sxsrf=ALiCzsa8GTA53SYSV4ULMNcf9Ch03PGhrg:1651414443860&amp;ei=q5VuYpqSNLrQkPIP4IClCA&amp;ved=0ahUKEwjak7aavr73AhU6KEQIHWBACQEQ4dUDCA0&amp;uact=5&amp;oq=european+towing+standards+site:tab-rv.vanillacommunity.com&amp;gs_lcp=Cgdnd3Mtd2l6EANKBAhBGAFKBAhGGABQnQlY0UNg50loAXAAeACAAZEBiAGTGJIBBDQwLjGYAQCgAQHAAQE&amp;sclient=gws-wiz

Viajero

pthomas745 said:

The video with the European trailers/vehicles are not applicable in any way for vehicles in the USA. Everything about European towing and safety design standards is completely different from the US safety and design standards.  Cars are different, tow hitches are different, road speeds are different, etc. So, take that video with a big grain of European salt.

Every once in a while someone shows up in various forums towing a Tab with a much too small vehicle, and when confronted, the claim is "They tow with it in Europe, so why not?"

Here are the threads:

https://www.google.com/search?q=european+towing+standards+site:tab-rv.vanillacommunity.com&amp;client=firefox-b-1-d&amp;sxsrf=ALiCzsa8GTA53SYSV4ULMNcf9Ch03PGhrg:1651414443860&amp;ei=q5VuYpqSNLrQkPIP4IClCA&amp;ved=0ahUKEwjak7aavr73AhU6KEQIHWBACQEQ4dUDCA0&amp;uact=5&amp;oq=european+towing+standards+site:tab-rv.vanillacommunity.com&amp;gs_lcp=Cgdnd3Mtd2l6EANKBAhBGAFKBAhGGABQnQlY0UNg50loAXAAeACAAZEBiAGTGJIBBDQwLjGYAQCgAQHAAQE&amp;sclient=gws-wiz

I’ll respectfully disagree. The physics doesn’t change. Engineering is a little different as they shoot for hitch weights of 4 to 9 percent. 

Many people towing t@bs tow with SUV’s and many are similar in size to European SUV’s. 

I think the videos suggestions of cargo loading are valid and good knowledge for any T@B owner. One of the worst things I see on many trailers I see now are those big racks on the back of the trailers. Hundreds of pounds on the end of a trailer swinging around. What could go wrong. 

Jmho 

Denny16

The video posted above was from Australia, and they use the same towing standards that is used in North America, so the basic info does apply here.  Australia hitches on the average are also more robust built, as a lot of RV towing is on dirt type roads, especially in the outback, where there are few paved roads.  

European standards are very different than North America and Australia, as towing speed are much slower, and roads are narrower on the average. 

Cheers 

AnOldUR

Viajero said:

One of the worst things I see on many trailers I see now are those big racks on the back of the trailers. Hundreds of pounds on the end of a trailer swinging around. What could go wrong. 

That would be me.  :(

My weak defense would be that my tongue weight is within the recommended 10-15% range. 

pthomas745

I would like to apologize to all the Australians in the group for confusing the video with a European video.  Thanks for straightening me out!

Denny16

No worries mate, it’s all good….  And that video did show quite well the effects of having to little or too much weight on the tongue.
cheers

Viajero

AnOldUR said:

Viajero said:

One of the worst things I see on many trailers I see now are those big racks on the back of the trailers. Hundreds of pounds on the end of a trailer swinging around. What could go wrong. 

That would be me.  :(

My weak defense would be that my tongue weight is within the recommended 10-15% range. 

Actually I don’t think that’s as bad as those decks that are hanging off the back of new trailers. They are actually a factory option. At least your is not that far behind the axle. 

Jmho.