Real Tongue Weights 23FB, 25RB & F-150

[dznf0g]

Originally Posted by bobzdar

Yeah, mathematically, the weight of both trailer and tv get redistributed. End result, you can put 1/3 of the original coupler weight back onto the TV as measured and the other 2/3 on the tow vehicle (as measured). Can you get a perfect 1/3 on each axle(s)? Probably not, and not worth attempting, but you're attempting to get weight back onto the steering axle and onto the trailer axles so you're not towing dangerously or exceeding gawr or gvwr ratings. So I guess the better question here is - is it realistic to put 1/3 of the coupler weight back on the trailer and where does that leave the distribution on the TV? Is at least the original weight on the front axle? In almost all cases, yes, and more than that. Which is fine. Unless you have some really weird setup, the weight won't be more on the front than the rear, which could be dangerous.

Ok, I don't think my setup is weird...very common double cab regular (bed 6.5') pickup and a 30' AS. Weird?

993 coupler weight

52% FA return puts 84# on TA(8.5%);739# on RA (74%);170# on FA (17%)

75% FA return puts 122# on TA(12%);623# on RA(63%); 248# on FA(25%)

100% FA Return puts 163# on TA(16%);501# on RA(51%);329# on FA(33%)

140% FA return puts 277# on TA(28%);256# on RA(26%);460# on FA(46%)

Where is any of those settings anywhere close to 1/3, 1/3, 1/3?

Once again, the only way to have equal distribution of coupler weight is if TA to ball length + ball to RA distance = TV WB. The only way. Tilt, ball height (within reason) have nothing to do with it.

[jcl]

Originally Posted by dznf0g

Well, that verbiage is just flat wrong. It won't happen.

I agree that the % split will be in part a function of geometry of the combination, eg the various moment arm lengths, as well as the ball height.

I didn’t post it, but the 2007 Classic owner’s manual has the same information as I posted above, plus a graphic.

[dznf0g]

Originally Posted by jcl

I agree that the % split will be in part a function of geometry of the combination, eg the various moment arm lengths, as well as the ball height.

I didn’t post it, but the 2007 Classic owner’s manual has the same information as I posted above, plus a graphic.

That doesn't surprise me, I guess. I just don't have my manual available to me at home right now.

[dznf0g]

I did a bit more "what if " noodling. With my truck dimensions, in order to have 1/3,1/3, 1/3 distribution, I would need a trailer which measures 86.26" from axle to coupler. That's a SHORT trailer!!

Not sure what a 16 basecamp or bambi is for that spec, but I envision it is more.

[foobar]

Originally Posted by bobzdar

Yeah, mathematically, the weight of both trailer and tv get redistributed. End result, you can put 1/3 of the original coupler weight back onto the TV as measured and the other 2/3 on the tow vehicle (as measured). Can you get a perfect 1/3 on each axle(s)? Probably not, and not worth attempting, but you're attempting to get weight back onto the steering axle and onto the trailer axles so you're not towing dangerously or exceeding gawr or gvwr ratings. So I guess the better question here is - is it realistic to put 1/3 of the coupler weight back on the trailer and where does that leave the distribution on the TV? Is at least the original weight on the front axle? In almost all cases, yes, and more than that. Which is fine. Unless you have some really weird setup, the weight won't be more on the front than the rear, which could be dangerous.

Seems like most of the responders here are generally aligned, we are just debating fine points.

Thinking about everyone's responses got me thinking about what the goals of implementing and tuning a WD hitch should be. Slight differences in what folks might be perceiving the goals are can easily drive differences of opinion as to what they should do in terms of setting up a WD based tow system.

I'll take a stab at goals and would like to hear what your thoughts are too.

To frame the goals, let's start with a couple of points:

1. Tow vehicle axle ratings are almost always asymmetric, especially for trucks. I.e. the rear axle and suspension are designed to handle a lot more load than the front axle.
2. The tow vehicle will have to support the weight of the majority of the trailer tongue weight (including the WD hitch weight) along with the weight of any cargo and/or passengers that are carried within the tow vehicle.

Goals:

1. For stable towing: Maintain trailer tongue weight within 10-15% of fully loaded trailer weight
2. For stable towing/braking: Trailer should be level or "very slightly nose down" after WD tension is applied
3. For safety and reliability: Meet all limits: Tow vehicle GVWR, Front/Rear GAWR, GCWR along with hitch load limits plus meet trailer GVWR and GAWR limits
4. For braking and steering: By applying WD bar tension, restore enough of the TV front axle loading to ensure safe braking and steering capability for the front wheels.
5. Follow tow vehicle manufacturer recommendations for how much front axle loading to restore. For example, Ford recommends using only enough WD tension to restore 50% the front axle suspension deflection.

Now, let's think about the implications of the points and goals listed above.

Regarding point number 1 above:

For an F250 that I looked up online, the Front/Rear gross axle weight ratings (GAWR) are 5600 and 6340 lbs respectively. The ratio of front to rear weight rating is 0.88.

For my Cayenne, the Front/Rear GAWR's are 2998 and 3417 respectively. The ratio of front to rear rating is 0.88.

Side note: oddly enough, these ratios are identical and therefore the Cayenne doesn't have an unusually weak front axle as was suggested before.

Back to the main point that I'm trying to make. All vehicles that are designed to carry loads in the rear of the vehicle (trucks, SUV's, etc) will have a higher GAWR rating for the rear axle.

I.e. it doesn't make sense to distribute 1/3 of the tongue weight to the weakest axle, even if you wanted to. You want to and need to carry more of the weight on the tow vehicle rear axle.

Consider goal #4 above. Ford's towing guide says to only restore 50% of the front axle suspension deflection when applying WD tension. This means that most of the tongue load will be carried by the heavier duty rear axle that has a correspondingly higher GAWR value.

The key messages or points to walk away with are:

• Tow vehicles are designed to carry most of any additional loads (e.g. tongue weight on their rear axles).
• The 1/3rd rule of thumb for evenly distributing the tongue weight across the tow vehicle front axle, rear axle and trailer axles will never happen in any real world combination of tow vehicle + WD hitch + trailer that is properly configured and meets the tow vehicle manufacturer requirements.
• Even if you can force the WD tension to be so high that 1/3rd of the tongue weight is on the tow vehicle front axle, you should not do so as it is not the axle where the tow vehicle is design to carry such a high percentage of the cargo load (cargo load includes the tongue weight).

I will send a 6 pack of beer to anyone can achieve an even 1/3rd distribution of tongue weight (trailer tongue weight includes the full weight of the entire WD hitch, stinger, torsion bars, etc) and whose tow vehicle plus trailer remains level (or the trailer ends up very, very slightly nose down) when the WD bars are tensioned to the level that achieves the 1/3rd weight distribution rule of thumb.

[foobar]

Originally Posted by dznf0g

I did a bit more "what if " noodling. With my truck dimensions, in order to have 1/3,1/3, 1/3 distribution, I would need a trailer which measures 86.26" from axle to coupler. That's a SHORT trailer!!

Not sure what a 16 basecamp or bambi is for that spec, but I envision it is more.

That's a short trailer with a huge load! And 86" would include at least 24-30 inches or so for the A-frame up front.

It's a shame that even Airstream has codified the 1/3rd WD weight transfer urban legend into their owners manual.

[foobar]

Originally Posted by dznf0g

Ok, I don't think my setup is weird...very common double cab regular (bed 6.5') pickup and a 30' AS. Weird?

993 coupler weight

52% FA return puts 84# on TA(8.5%);739# on RA (74%);170# on FA (17%)

75% FA return puts 122# on TA(12%);623# on RA(63%); 248# on FA(25%)

100% FA Return puts 163# on TA(16%);501# on RA(51%);329# on FA(33%)

140% FA return puts 277# on TA(28%);256# on RA(26%);460# on FA(46%)

Where is any of those settings anywhere close to 1/3, 1/3, 1/3?

Once again, the only way to have equal distribution of coupler weight is if TA to ball length + ball to RA distance = TV WB. The only way. Tilt, ball height (within reason) have nothing to do with it.

Thanks for sharing this info.

And which configuration above do you tow with? And is the tow vehicle and trailer level when that amount of WD bar tension is applied?

[dznf0g]

Originally Posted by foobar

Seems like most of the responders here are generally aligned, we are just debating fine points.

Thinking about everyone's responses got me thinking about what the goals of implementing and tuning a WD hitch should be. Slight differences in what folks might be perceiving the goals are can easily drive differences of opinion as to what they should do in terms of setting up a WD based tow system.

I'll take a stab at goals and would like to hear what your thoughts are too.

To frame the goals, let's start with a couple of points:

1. Tow vehicle axle ratings are almost always asymmetric, especially for trucks. I.e. the rear axle and suspension are designed to handle a lot more load than the front axle.
2. The tow vehicle will have to support the weight of the majority of the trailer tongue weight (including the WD hitch weight) along with the weight of any cargo and/or passengers that are carried within the tow vehicle.

Goals:

1. For stable towing: Maintain trailer tongue weight within 10-15% of fully loaded trailer weight
2. For stable towing/braking: Trailer should be level or "very slightly nose down" after WD tension is applied
3. For safety and reliability: Meet all limits: Tow vehicle GVWR, Front/Rear GAWR, GCWR along with hitch load limits plus meet trailer GVWR and GAWR limits
4. For braking and steering: By applying WD bar tension, restore enough of the TV front axle loading to ensure safe braking and steering capability for the front wheels.
5. Follow tow vehicle manufacturer recommendations for how much front axle loading to restore. For example, Ford recommends using only enough WD tension to restore 50% the front axle suspension deflection.

Now, let's think about the implications of the points and goals listed above.

Regarding point number 1 above:

For an F250 that I looked up online, the Front/Rear gross axle weight ratings (GAWR) are 5600 and 6340 lbs respectively. The ratio of front to rear weight rating is 0.88.

For my Cayenne, the Front/Rear GAWR's are 2998 and 3417 respectively. The ratio of front to rear rating is 0.88.

Side note: oddly enough, these ratios are identical and therefore the Cayenne doesn't have an unusually weak front axle as was suggested before.

Back to the main point that I'm trying to make. All vehicles that are designed to carry loads in the rear of the vehicle (trucks, SUV's, etc) will have a higher GAWR rating for the rear axle.

I.e. it doesn't make sense to distribute 1/3 of the tongue weight to the weakest axle, even if you wanted to. You want to and need to carry more of the weight on the tow vehicle rear axle.

Consider goal #4 above. Ford's towing guide says to only restore 50% of the front axle suspension deflection when applying WD tension. This means that most of the tongue load will be carried by the heavier duty rear axle that has a correspondingly higher GAWR value.

The key messages or points to walk away with are:

• Tow vehicles are designed to carry most of any additional loads (e.g. tongue weight on their rear axles).
• The 1/3rd rule of thumb for evenly distributing the tongue weight across the tow vehicle front axle, rear axle and trailer axles will never happen in any real world combination of tow vehicle + WD hitch + trailer that is properly configured and meets the tow vehicle manufacturer requirements.
• Even if you can force the WD tension to be so high that 1/3rd of the tongue weight is on the tow vehicle front axle, you should not do so as it is not the axle where the tow vehicle is design to carry such a high percentage of the cargo load (cargo load includes the tongue weight).

I will send a 6 pack of beer to anyone can achieve an even 1/3rd distribution of tongue weight (trailer tongue weight includes the full weight of the entire WD hitch, stinger, torsion bars, etc) and whose tow vehicle plus trailer remains level (or the trailer ends up very, very slightly nose down) when the WD bars are tensioned to the level that achieves the 1/3rd weight distribution rule of thumb.

Al of that is correct, impo.

[dznf0g]

Originally Posted by foobar

Thanks for sharing this info.



And which configuration above do you tow with? And is the tow vehicle and trailer level when that amount of WD bar tension is applied?

I tow at 52%. GM, like Ford requires as close to 50% as possible. The rig is level...perhaps 1/4 to 1/2" low in front, over a 25 foot span. I measure at the lower belt at the clamshell seams.

[foobar]

Originally Posted by dznf0g

I tow at 52%. GM, like Ford requires as close to 50% as possible. The rig is level...perhaps 1/4 to 1/2" low in front, over a 25 foot span. I measure at the lower belt at the clamshell seams.

Well, if this was a courtroom, it would probably be time to say "the defense rests"

Your optimal configuration is thus:

52% Front axle return puts 84# on the trailer axles (8.5%)
739# on tow vehicle rear axle (74%)
170# on tow vehicle front axle (17%)

That's just a wee bit away from 33.3%, 33.3%, 33.3% tongue weight distribution And I expect many folks with pickup trucks as their tow vehicle (especially heavy duty truck owners) and similar length Airstreams will end up with roughly similar ratios.

[dznf0g]

Originally Posted by foobar

Well, if this was a courtroom, it would probably be time to say "the defense rests"

Your optimal configuration is thus:

52% Front axle return puts 84# on the trailer axles (8.5%)
739# on tow vehicle rear axle (74%)
170# on tow vehicle front axle (17%)

That's just a wee bit away from 33.3%, 33.3%, 33.3% tongue weight distribution

Yup, I should say, GM, since 2004 has required 50% return on FSPUs. Everyone should read their manual. It depends heavily on suspension design and body configuration.

[TNOutback]

Can we get back to my original post question? I’d like to hear from 23FBT and 25RBT owners about their real-world, packed for travel, measured tongue weights? A good population sample to do some Statistics 101 would be nice. Somehow we’ve drifted off into weight distribution theory and practice!

[ROBERT CROSS]

Type the question in the search box at the beginning of the thread...Loaded tongue weight for 23fbt

It werks.

Bob
🇺🇸

[gypsydad]

Originally Posted by TNOutback

Can we get back to my original post question? I’d like to hear from 23FBT and 25RBT owners about their real-world, packed for travel, measured tongue weights? A good population sample to do some Statistics 101 would be nice. Somehow we’ve drifted off into weight distribution theory and practice!

My actual tongue weight on my "then new" 2014 25' RBT Flying Cloud was 1080lbs loaded. Tongue weight was a main reason I sold my "then new" 2014, F150 EB, 4x4, Platinum model- it was always way over it's "payload" specs, which I didn't understand when I purchased it..."payload? what's payload mean? This truck can tow 12000lbs, right?

Someone here on the Forum alerted me to the importance of "payload". Could it pull/tow my 25' AS RBT? Yes, very well....but, I was outside recommended payload specs, and that was not a good feeling, having gone thru 2 "new" Tahoe's and 2 previous 25' FC model AS's, without realizing the importance of checking/knowing payload...loved driving it around town and miss not being able to put my F250 in the garage vs the F150..

[2012FB]

Originally Posted by gypsydad

My actual tongue weight on my "then new" 2014 25' RBT Flying Cloud was 1080lbs loaded. Tongue weight was a main reason I sold my "then new" 2014, F150 EB, 4x4, Platinum model- it was always way over it's "payload" specs, which I didn't understand when I purchased it..."payload? what's payload mean? This truck can tow 12000lbs, right?

Someone here on the Forum alerted me to the importance of "payload". Could it pull/tow my 25' AS RBT? Yes, very well....but, I was outside recommended payload specs, and that was not a good feeling, having gone thru 2 "new" Tahoe's and 2 previous 25' FC model AS's, without realizing the importance of checking/knowing payload...loved driving it around town and miss not being able to put my F250 in the garage vs the F150..

Sorry to hear that you did not do the proper research prior to making such a big purchase, but happy you got it figured out in the end.

[richard5933]

Originally Posted by TNOutback

Can we get back to my original post question? I’d like to hear from 23FBT and 25RBT owners about their real-world, packed for travel, measured tongue weights? A good population sample to do some Statistics 101 would be nice. Somehow we’ve drifted off into weight distribution theory and practice!

Looks like you've got about a dozen real-world weigh-ins in this thread. Not sure that you'll get much more data with another few dozen as the numbers already posted are pretty typical from what I've seen on Air Forum. The tongue is likely going to weight somewhere between 900-1100 pounds for a 25-ft trailer, depending on the exact layout and how carefully you pack & load.

[gypsydad]

Originally Posted by 2012FB

Sorry to hear that you did not do the proper research prior to making such a big purchase, but happy you got it figured out in the end.

Yea, after owning a Class A, a pop up, a Casita, a 06' 25' Safari, an 08' 25' FC, you would think I would have been all over the important stuff, like safety, payload, and proper tow vehicles, right?