Help with hitch / tongue weight

Ron Gratz wrote:


You are correct that adding load behind the TV's rear axle, with WD engaged, will cause load to be transferred to the TT's axles.

And all I'm saying is that this additional load should and can be considered "TONGUE WEIGHT" since that is what the WDH is designed to do and that is to DISTRIBUTE TONGUE WT. which in this case included that extra cargo wt. that constructively appears at the ball/coupler position.

However, transferring load to the TT's axles does not cause the vertical load on the hitch/receiver to be increased.
Quite the opposite -- it causes the vertical load on the hitch/receiver to be decreased.

And I don't think I ever said that ... hoewever just like normal tongue wt. which undistributed is what you compare against the receiver's specs and size your WDH bars for the actual numbers at the various points are not in question. If that were the case then you could say load up a WDH system where the TV wt. is increased by the reveiver number and that would well exceed the receivers specifications by the amount that the TT axle wt. increases because of the WDH.

Ron

I think the whole point here is to understand what wts. we should be considering if we want to say within the specifications of the various components of the WDH system (i.e. receiver, WDH bars, etc.)

Folks IMO are looking at what is called "TONGUE WEIGHT" is too narrow of a definition is IMO again it is composed in a WDH configuration of several components, one of those being this temporary cargo wt.

Larry

Tongue weight is typically defined as the static force the trailer tongue exerts on the hitch ball. Setting up the WD system, to distribute the tongue weight AND the cargo in the bed that you typically haul is obviously the best setup. But, that doesn't mean that the weight you add to the bed, even if it is behind the axles, is tongue weight. What you are distributing is tongue weight AND the cargo weight that is behind the rear axle. None of the added cargo is tongue weight, but it can be part of what needs to be distributed.

Mike

LarryJM wrote:
NO the fact is your view is just YOUR OPINION which is NOT SHARED by many others including those who produce hardware. The purpose of a WDH is to redistribute the weight (called "TONGUE WEIGHT") that is put on the ball of the hitch and once you hook up the WDH system adding cargo aft of the TV rear axle will increase that value and show up as weights applied to the axles of both the trailer and the TV. Hook up your trailer run across the scales and then have someone stand on your rear bumper and do a second run across the scales and all your weights including those on the TT axles will change. That can only happen if the "TONGUE WEIGHT" has changed unless you have adjusted your WDH system.

In the end as I said in that link there are two "camps" on this and your are in one and I'm in the other, you're not probably going to change unless you're willing to learn and listen rationally and I'm not going to change unless my CAT scale example above was proven to not be correct and all that weight from that person on the rear bumper only showed up on the TV axles only.

Larry, here's what's going to happen if you put someone on the rear bumper and make a second run across the scales:

The weight of the second person (let's assume 200#) will cause the front of the TV to rise and the rear of the TV (and the ball) to drop.
The drop of the ball changes the vertical angle between TV and TT and causes the WD bars to pull down harder on the A-frame.

The increased downward force on the A-frame will cause increased downward force on the TT's tires.
Consistent with Newton's third law, the pavement then will exert an increased upward force on the tires.
Let's say this increased upward force is 50#.
Let's also say that prior to adding the 200# person to the TV's bumper, the TT was exerting a downward force of 800# on the WDH.

Since the pavement now is exerting an added upward force of 50# on the TT (without changing the mass of the TT), the previous downward force of 800# acting on the WDH will be reduced by 50# leaving a downward force of 750# acting on the WDH.

Increasing the load on the WD bars always reduces the magnitude of vertical downward load acting on the hitch head.
Otherwise, the WDH could not cause load to be removed from the TV's rear axle and added to the front.

You are correct that adding load behind the TV's rear axle, with WD engaged, will cause load to be transferred to the TT's axles.
However, transferring load to the TT's axles does not cause the vertical load on the hitch/receiver to be increased.
Quite the opposite -- it causes the vertical load on the hitch/receiver to be decreased.

Ron

LarryJM wrote:
---Ron in his last post agrees at least in concept with parts of my position.---

Larry,

In the previous thread to which you referred, you stated "---but I also think that cargo added after the rear axle on the TV and after you have set up your WDH should also be counted in the TW.---"

Just for the record, there is nothing in that statement with which I agree -- conceptually or otherwise.

IMO, no part of TV cargo should be considered to be part of TT "tongue weight".

Ron

ktmrfs wrote:
Rather than talk about what is or is not tongue weight, I think about it more of what weight do I want the WD hitch to distribute. Like Larry, My truck bed is usually pretty full.

even w/o the trailer hooked up, the front of the truck rises some, not much but some.

I've set my WD hitch up so that with my typical truck bed load AND the trailer hooked up, once the bars are engaged, the front of the truck is back to the level it is if there is NOTHING in the truck bed and NO trailer hooked up.

So, like Larry, my WD hitch is transferring this extra weight, in this case tongue weight and stuff behind the truck axle, back to the TV front axle and Trailer rear axle.

CORRECT and at least YOU UNDERSTAND and what does get somewhat confusing is using the term "TONGUE WEIGHT" and thinking it's a fixed value. I like to refer to the weight of just the trailer tongue as "dead tongue weight" to differentiate it to things like tongue wt as used in receiver capacities and even WDH bar sizing where the latter includes this temporary "CARGO" weight.

Larry

Rather than talk about what is or is not tongue weight, I think about it more of what weight do I want the WD hitch to distribute. Like Larry, My truck bed is usually pretty full.

even w/o the trailer hooked up, the front of the truck rises some, not much but some.

I've set my WD hitch up so that with my typical truck bed load AND the trailer hooked up, once the bars are engaged, the front of the truck is back to the level it is if there is NOTHING in the truck bed and NO trailer hooked up.

So, like Larry, my WD hitch is transferring this extra weight, in this case tongue weight and stuff behind the truck axle, back to the TV front axle and Trailer rear axle.

lbrjet wrote:
With your theory Larry my truck's bumper, receiver, tail gate, spare tire and everything else aft of the rear tires would be considered tongue weight.

When you set up a WDH you are supposed to load the truck as you would for camping first. This is the baseline for all further calculations and none of this weight is tongue weight.

We can just agree to disagree.

You're not reading what I said ... your bumper, receiver, tail gate, spare tire are not CARGO that is added temporarily after your WDH has been adjusted for an unloaded condition. As such they are not germane to what I'm talking about. My example of standing on the bumper after running across the scales with your WDH engaged is an example of CARGO added. Furthermore any weight that never varies that is after the rear axle also doesn't fall into the cargo category that should be considered "TONGUE WEIGHT" as it is used in the receiver and WDH capacities in a WDH configuration.

In a non WDH configuration temporary cargo aft the the axle does not go against the "TONGUE WEIGHT" receiver capacities, but the drawbar/hitch head of say a WDH type system along with anything attached to the drawbar like a bike rack along with the bikes do count against that number.

For most folks this issue is very minor, but in my case I have at times carry in excess of 250lbs of temporary cargo whose weight is basically at the extreme rear of my van on the top of my secure storage area as seen in the pic below (that is 4 yellow diesel fuel containers, a EU2000 generator and a toolbox full of tools along with some other misc items.



Larry

With your theory Larry my truck's bumper, receiver, tail gate, spare tire and everything else aft of the rear tires would be considered tongue weight.

When you set up a WDH you are supposed to load the truck as you would for camping first. This is the baseline for all further calculations and none of this weight is tongue weight.

We can just agree to disagree.

Terryallan wrote:

LarryJM wrote:

Terryallan wrote:

lbrjet wrote:
Weight in the back of your truck counts against payload, but it is not tongue weight.

This is the correct answer. The load in the back of the truck, including the hitch itself is NOT tongue weight. It is part of the payload / GVWR of the truck.
Tongue weight. Is the actual weight of the trailer tongue. Determined mostly by where you load the weight INSIDE the trailer.

Thing is. You have to leave enough payload to carry the tongue weight, because it too counts against the payload / GVWR of the truck. You also have to be sure your receiver is rated to carry the tongue weight of your trailer. Say your receiver can carry 950lb of tongue weight using a WDH. Your tongue weight cannot be more than 950lb.

And do remember. the truck's brakes are only designed to stop the GVWR of the truck. They are NOT designed to stop the GCVWR which is the truck, plus the trailer. In other words, They are not designed stop the GCVWR of the truck.

That view is IMO too simplistic and not really correct. My answer to this is in my post HERE. Ron in his last post agrees at least in concept with parts of my position. I do agree with his view as it applies to what to use as the percentage of TW to total trailer wt. to estimate overall trailer stability.

I do concede that my position regarding cargo aft of the TV rear axle is fairly complex and near impossible to accurately determine since what is important for receiver TW rating and sizing of WDH bars is the "weight" that would be applied at the point of the ball that would equal the same "lever moment" as this "additional" cargo wt. I would think somewhere this would be in the range of 25-75% of the actual cargo wt. added.

Larry

Simplistic or not. It is factual. Tongue weight. It ONLY the weight of the trailer tongue. Weigh the tongue alone to get it. When hooked to the truck. the tongue weight takes up part of the payload / GVWR. Pretty much it.
To say that the cargo in the back of the truck is part of the tongue weight is not realistic. After all, Unhook the trailer and that cargo weight is still there, but the tongue weight is completely gone. what would you call it then? No tongue, no tongue weight.

NO the fact is your view is just YOUR OPINION which is NOT SHARED by many others including those who produce hardware. The purpose of a WDH is to redistribute the weight (called "TONGUE WEIGHT") that is put on the ball of the hitch and once you hook up the WDH system adding cargo aft of the TV rear axle will increase that value and show up as weights applied to the axles of both the trailer and the TV. Hook up your trailer run across the scales and then have someone stand on your rear bumper and do a second run across the scales and all your weights including those on the TT axles will change. That can only happen if the "TONGUE WEIGHT" has changed unless you have adjusted your WDH system.

In the end as I said in that link there are two "camps" on this and your are in one and I'm in the other, you're not probably going to change unless you're willing to learn and listen rationally and I'm not going to change unless my CAT scale example above was proven to not be correct and all that weight from that person on the rear bumper only showed up on the TV axles only.

Larry

LarryJM wrote:

Terryallan wrote:

lbrjet wrote:
Weight in the back of your truck counts against payload, but it is not tongue weight.

This is the correct answer. The load in the back of the truck, including the hitch itself is NOT tongue weight. It is part of the payload / GVWR of the truck.
Tongue weight. Is the actual weight of the trailer tongue. Determined mostly by where you load the weight INSIDE the trailer.

Thing is. You have to leave enough payload to carry the tongue weight, because it too counts against the payload / GVWR of the truck. You also have to be sure your receiver is rated to carry the tongue weight of your trailer. Say your receiver can carry 950lb of tongue weight using a WDH. Your tongue weight cannot be more than 950lb.

And do remember. the truck's brakes are only designed to stop the GVWR of the truck. They are NOT designed to stop the GCVWR which is the truck, plus the trailer. In other words, They are not designed stop the GCVWR of the truck.

That view is IMO too simplistic and not really correct. My answer to this is in my post HERE. Ron in his last post agrees at least in concept with parts of my position. I do agree with his view as it applies to what to use as the percentage of TW to total trailer wt. to estimate overall trailer stability.

I do concede that my position regarding cargo aft of the TV rear axle is fairly complex and near impossible to accurately determine since what is important for receiver TW rating and sizing of WDH bars is the "weight" that would be applied at the point of the ball that would equal the same "lever moment" as this "additional" cargo wt. I would think somewhere this would be in the range of 25-75% of the actual cargo wt. added.

Larry

Simplistic or not. It is factual. Tongue weight. It ONLY the weight of the trailer tongue. Weigh the tongue alone to get it. When hooked to the truck. the tongue weight takes up part of the payload / GVWR. Pretty much it.
To say that the cargo in the back of the truck is part of the tongue weight is not realistic. After all, Unhook the trailer and that cargo weight is still there, but the tongue weight is completely gone. what would you call it then? No tongue, no tongue weight.