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06-11-2020, 06:35 AM
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#361
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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Quote:
Originally Posted by dasams
When my wife and I decided to full time in 2016, we bought a FC 25RB and towed it with my 2006 Cayenne S. Drove all over the western US, down the Baja to Cabo and then to Alaska.
On our way to Homer AK in the Kenai peninsular, I was looking at fisherman on my left and didn’t see the truck that was stopped in front of me. At the last second, I hit the brakes as hard as I could. I mean lifting my a$$ out of the seat. The ABS never activated because of the weight and no skidding. Totally stable stop. I have a 7 sec video from my dash cam if anyone is interested.
For me, I’ll always tow with a capable SUV. YMMV.
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The Cayenne is a standout among the performance SUVs. Few are as capable at towing 7000 or more pounds. If you don't need much cargo space, they are an excellent choice. The performance SUVs all stop well, but so do 3/4 ton trucks towing the same weight.
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06-11-2020, 06:53 AM
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#362
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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Quote:
Originally Posted by RV4Mark
Thank you all for your thoughtful responses to my question. While I completely understand the concept and the math, I’m still at a loss. Please let me explain: Supposedly my Raptor has a maximum tongue weight of 500 lbs. However this increases to 1,200 lbs if using a weight distribution hitch. So with that in mind, I’m assuming that by using a weight distribution hitch, the trailer tongue weight is not necessarily a 1-to-1 subtraction from the cargo carrying capacity.
For example that’s a 1:2.4 ratio. (I figured out the ratio of 1:2.4 because supposedly the truck’s tongue dead weight max is 500, but max tongue weight with a weight distribution hitch is 1,200 lbs)
So wouldn’t that mean if the tongue dead weight of the Airstream is 1,000 lbs, that because I am using a weight distribution hitch, I do not need to subtract the full 1,000 lbs from the cargo carrying capacity? Wouldn’t that mean I subtract only 416 lbs? (1,000 Airstream tongue dead weight, divided by 2.4)?
Thanks!
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As others indicate that is not the operating ratio. The actual ratio that determines final reduction in payload is a function of the truck wheel base and the length from the rear axles to the ball mount. It will be about 1.5 for the short wheelbase Raptor. The 30 ft trailer properly loaded is going to have a tongue weight of at least 1,100 lbs and divided by 1.5, that is 733 lbs. But as others have noted the tongue limit with WD is likely not 1,200, it may be 800. Again that puts you over. You could carefully load the trailer to get tongue weight down to near 10%, but I would strongly discourage that, as trailer stability is compromised making it risky.
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06-11-2020, 07:11 AM
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#363
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Rivet Master
2017 23' Flying Cloud
Bartlett
, Tennessee
Join Date: Apr 2017
Posts: 1,057
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Using a weight distribution hitch does not remove weight from the hitch, therefore it does not reduce the amount of weight that must be counted against payload. It redistributes some of the weight from the rear tires of the tow vehicle to the front tires and the trailer tires. But, every pound of tongue weight is still on the hitch. Whatever the full amount of your tongue weight is, all of it, must be counted against the truck payload. Always.
__________________
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab 3.5l EcoBoost V6
2017 Flying Cloud 23FB "BobLin Along"
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06-11-2020, 07:20 AM
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#364
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Rivet Master
2006 25' Safari
St. Augustine
, Florida
Join Date: Oct 2011
Posts: 2,670
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It is simple. The truck manufacturer makes it easy. On a Ford, there is a sticker inside the door that says not to exceed a certain weight. This number is for that specific truck build- the axles, the engine trans, etc. As for the weight, it is what it is. When you measure the tongue weight, whatever the weight is does not change because of a redistribution- it is still there and, different devices distribute it differently. Your hitch on the truck also has a weight limit- check for a sticker. Yes, no matter what, the tongue weight is subtracted from the payload as it is a downward weight and not a pull weight. Now you know the limit of the half ton.
__________________
WBCCI 8653/AIR 60240
2022 Ford F150 PowerBoost Platinum w/7.2KW
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06-11-2020, 07:42 AM
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#365
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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Quote:
Originally Posted by Bobbo
Using a weight distribution hitch does not remove weight from the hitch, therefore it does not reduce the amount of weight that must be counted against payload. It redistributes some of the weight from the rear tires of the tow vehicle to the front tires and the trailer tires. But, every pound of tongue weight is still on the hitch. Whatever the full amount of your tongue weight is, all of it, must be counted against the truck payload. Always.
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No, my previous description is correct, from a statics perspective, net load is in fact removed from the tow vehicle and is instead carried by the trailer axles.
Dynamic loads are a different matter and here there can be some debate. Since payload limits are primarily based on structural capacity, passenger comfort and suspension travel limits, it will vary from vehicle to vehicle whether or not one must(should) count weight distributed to the trailer axle against payload. Dynamic forces will shift bar tension and the transferred weight as a function of hitch point yaw angle. If suspension is under-damped and spring rates are low, suspension may bottom out. In this case you would be wise to count it.
Edit: It is unfortunate, but in the English speaking world, weight is not weight. The word means both mass and force and when dealing with systems that have weight distributing components, the terms get messed up. Tongue weight is the portion of trailer mass that acts on the tongue, but it is also the load imparted against the ball due to the sum of all torque moments at any given time. This is quite unfortunate.
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06-11-2020, 08:41 AM
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#366
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Quote:
Originally Posted by KCurtis
Wow! My 2019 High Country 6.2L pulling my 2020 25RB has only been getting 10.6 MPG. That is with premium gas too.
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Whats going on here with todays TV's?
9.8 to 10.6 towing with a 2006 Vortic 496ci Burb.
Stock with cold air intake and Superchips FlashPac programmer. Plus all the payload we need.
Really...how important is mpg to safe enjoyable Streaming?🤔
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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06-11-2020, 09:27 AM
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#367
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3 Rivet Member
Currently Looking...
Highlands Ranch
, Colorado
Join Date: Sep 2019
Posts: 225
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Quote:
Originally Posted by ROBERT CROSS
Really...how important is mpg to safe enjoyable Streaming?🤔
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It depends on how large your fuel tank is.
I'm glad mine is 48 gallons.
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06-11-2020, 12:34 PM
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#368
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Rivet Master
2007 30' Classic
Oswego
, Illinois
Join Date: Jul 2010
Posts: 13,669
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Quote:
Originally Posted by ROBERT CROSS
Whats going on here with todays TV's?
9.8 to 10.6 towing with a 2006 Vortic 496ci Burb.
Stock with cold air intake and Superchips FlashPac programmer. Plus all the payload we need.
Really...how important is mpg to safe enjoyable Streaming?[emoji848]
Bob
[emoji631]
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Hmmm, 10.6 for me would be with a moderate head wind. Still air = north of 12. Day before yesterday, 570 miles with a moderate tailwind = 13.4.
I drive 65.
2015 ltz 6.2, 8 speed.
2007 30' classic @ 9k.
__________________
-Rich-
"If the women don't find you handsome, they should at least find you handy." - Red Green
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06-11-2020, 05:57 PM
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#369
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Rivet Master
2017 28' Flying Cloud
2014 25' FB Flying Cloud
2008 25' Safari FB SE
Georgetown (winter)Thayne (summer)
, Texas & Wyoming
Join Date: Jan 2007
Posts: 6,688
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Quote:
Originally Posted by dasams
When my wife and I decided to full time in 2016, we bought a FC 25RB and towed it with my 2006 Cayenne S. Drove all over the western US, down the Baja to Cabo and then to Alaska.
On our way to Homer AK in the Kenai peninsular, I was looking at fisherman on my left and didn’t see the truck that was stopped in front of me. At the last second, I hit the brakes as hard as I could. I mean lifting my a$$ out of the seat. The ABS never activated because of the weight and no skidding. Totally stable stop. I have a 7 sec video from my dash cam if anyone is interested.
For me, I’ll always tow with a capable SUV. YMMV.
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And how fast were you going? 60-65mph? We have been there couple times with our 25' AS and F150 also. With 28', also with the F250. I wouldn't chance a smaller SUV as a TV..with a 25' or larger AS...my choice, but many experts will agree the larger TV rated for TT weight is best/safest.YMMV
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06-11-2020, 07:20 PM
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#370
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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Quote:
Originally Posted by gypsydad
And how fast were you going? 60-65mph? We have been there couple times with our 25' AS and F150 also. With 28', also with the F250. I wouldn't chance a smaller SUV as a TV..with a 25' or larger AS...my choice, but many experts will agree the larger TV rated for TT weight is best/safest.YMMV
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Ooh, careful there, the Cayenne is tuned for towing. It needs a bit of support against wind induced sway but with a competent hitch, pulling up to 7500, it will out tow pretty much anything out there at pretty much any speed you choose.
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06-11-2020, 07:59 PM
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#371
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Rivet Master
2017 23' Flying Cloud
Bartlett
, Tennessee
Join Date: Apr 2017
Posts: 1,057
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Quote:
Originally Posted by BayouBiker
No, my previous description is correct, from a statics perspective, net load is in fact removed from the tow vehicle and is instead carried by the trailer axles.
Dynamic loads are a different matter and here there can be some debate. Since payload limits are primarily based on structural capacity, passenger comfort and suspension travel limits, it will vary from vehicle to vehicle whether or not one must(should) count weight distributed to the trailer axle against payload. Dynamic forces will shift bar tension and the transferred weight as a function of hitch point yaw angle. If suspension is under-damped and spring rates are low, suspension may bottom out. In this case you would be wise to count it.
Edit: It is unfortunate, but in the English speaking world, weight is not weight. The word means both mass and force and when dealing with systems that have weight distributing components, the terms get messed up. Tongue weight is the portion of trailer mass that acts on the tongue, but it is also the load imparted against the ball due to the sum of all torque moments at any given time. This is quite unfortunate.
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But you STILL have to count the entire tongue weight against the truck's payload. You can't reduce that number to make yourself feel better about towing over the payload limits.
__________________
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab 3.5l EcoBoost V6
2017 Flying Cloud 23FB "BobLin Along"
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06-11-2020, 08:04 PM
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#372
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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Why, Bobbo? Why do you have to count the load if its not acting on the axles? What is the physical rationale for counting it? If you sit the vehicle on a scale the load (weight) is not there. Neither of the axle weights are exceeded, nor is the total gross.
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06-12-2020, 05:45 AM
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#373
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4 Rivet Member
2015 27' Flying Cloud
Bozman
, Maryland
Join Date: Jul 2014
Posts: 294
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10.6 mpg?
Wow. My 2015 Sierra 1500 with the 6.2 and the Max trailer tow package (which was not sold on either the Chevy High Country or the GMC Denali) only did that poorly into a screaming headwind on the Texas panhandle pulling my FC 27. Usually 11-13+. My truck has the 8-speed, which was discontinued a few years later and I run at 60 or the posted limit, whichever is lower. (OEM Goodyear Marathons -since replaced-like to blow up at sustained speeds over 65.)
So, either the transmission- rear axle ratio for your truck is poor (max trailer tow package had a different rear axle and suspension), which is hard to imagine, or you’re running on the high side of 65 to burn that much more fuel. Puzzling 🤔
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06-12-2020, 06:32 AM
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#374
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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Quote:
Originally Posted by dznf0g
Hmmm, 10.6 for me would be with a moderate head wind. Still air = north of 12. Day before yesterday, 570 miles with a moderate tailwind = 13.4.
I drive 65.
2015 ltz 6.2, 8 speed.
2007 30' classic @ 9k.
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Rich,
I left out Kansas on our last cross country...14.1 west to east.🤔 An annamaliy for sure.
The Burb is really only used for towing or hauling stuff so normal mpg is just a guess, moot point for us as other parameters take precedence.
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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06-12-2020, 06:38 AM
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#375
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Rivet Master
2017 23' Flying Cloud
Bartlett
, Tennessee
Join Date: Apr 2017
Posts: 1,057
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Quote:
Originally Posted by BayouBiker
Why, Bobbo? Why do you have to count the load if its not acting on the axles? What is the physical rationale for counting it? If you sit the vehicle on a scale the load (weight) is not there. Neither of the axle weights are exceeded, nor is the total gross.
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Because, even though some load has been removed from the rear axle, all of that weight is still on the HITCH. If you want to say that you can remove some of the load from the rear axle GVWR, that is fine, but you can't remove it from the hitch, therefore the payload. The full tongue weight is pressing down on the hitch, then the WDH lifts up on the hitch to transfer some of the weight, but the weight is still on the hitch.
If you want to rationalize your choice to overload your tow vehicle's payload like this, I am not going to stop you. However, telling new people who are trying to learn how to load and tow that it is fine to overload their payload because they have a WDH is irresponsible.
Please note that I am talking about payload rating and you are talking about axle ratings. Those are not the same things. The only thing going into the axle rating is the axle. There are many, many things going into payload ratings in addition to the axle ratings. There are brakes, suspension, etc.
__________________
Bobbo and Lin
2017 F-150 XLT 4x4 SuperCab 3.5l EcoBoost V6
2017 Flying Cloud 23FB "BobLin Along"
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06-12-2020, 07:10 AM
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#376
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2 Rivet Member
Currently Looking...
Stuart
, Florida
Join Date: Aug 2016
Posts: 42
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I think 10+ is not that bad
I pull with a 5,3 GMC, and with most any kind of wind, I get 11 or so. Without the trailer, I get 20-21 open road.
So, I'm figuring a trailer pull costs a bout 10mpg. That's just what it costs.
ps..We used to have a winnebago view;MB diesel, and got 17 , or so, . We loved the rig, but it cost us a lot more to get another 6 mpg
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06-12-2020, 07:25 AM
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#377
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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The net torque and net weight on the hitch, shank and receiver are also reduced, it would have to be since net weight is shifted to the trailer axles. The compressible force on the ball is increased but neither the ball or the tongue are provided by the vehicle manufacturer so that can't be a payload concern, and the ball is unsupported to ground so the net force at the ball is always zero.
I think you misunderstand my questions, I happen to run just under limit without WD, I am asking here for discussion and clarification, because from a physics standpoint there does not seem to be a rationale. Perhaps it is a tradition, or maybe it is done to keep things simple and understandable. In order for it to be irresponsible the vehicle has to in fact be overloaded meaning excessive forces acting on the weakest component or exceeding one or more limiting parameter. I'm asking what that can be because from a statics standpoint, all torques and loads on the vehicle are reduced by WD.
I am trained and certified in static and dynamic mechanical systems including suspension, steering, braking, etc. Payload is primarily determined by structural limits (including the axle), suspension travel limits or desired level of comfort based mostly on spring rates, damping and vibration propagation.
Braking, handling, acceleration, motor and transmission performance are all limited by the combined weight limits not payload.
I didn't work for a long time in that area and I never had occasion to address payload limits directly at the time so I never was confronted with the question of how to handle payload limits with WD. Payload limit testing was not performed with heavy trailers attached (vehicles did tow a very small trailer which had test equipment on them).
I have asked old contacts about this and have not gotten a satisfactory answer. Nobody I know seems to know for sure other than what I said earlier which is it depends on the vehicle in question and what limit determined final payload.
I was hoping someone here might know.
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06-12-2020, 07:59 AM
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#378
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"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
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^
I don't pretend to know... so I just stay under axle & tire weight limits and depend on the Burbs robust construction for the rest.
Maybe if folks are that worried about payload limits...it's time for a TV change.
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
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06-12-2020, 08:01 AM
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#379
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3 Rivet Member
Currently Looking...
Highlands Ranch
, Colorado
Join Date: Sep 2019
Posts: 225
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Quote:
Originally Posted by BayouBiker
The net torque and net weight on the hitch, shank and receiver are also reduced, it would have to be since net weight is shifted to the trailer axles. The compressible force on the ball is increased but neither the ball or the tongue are provided by the vehicle manufacturer so that can't be a payload concern, and the ball is unsupported to ground so the net force at the ball is always zero.
I think you misunderstand my questions, I happen to run just under limit without WD, I am asking here for discussion and clarification, because from a physics standpoint there does not seem to be a rationale. Perhaps it is a tradition, or maybe it is done to keep things simple and understandable. In order for it to be irresponsible the vehicle has to in fact be overloaded meaning excessive forces acting on the weakest component or exceeding one or more limiting parameter. I'm asking what that can be because from a statics standpoint, all torques and loads on the vehicle are reduced by WD.
I am trained and certified in static and dynamic mechanical systems including suspension, steering, braking, etc. Payload is primarily determined by structural limits (including the axle), suspension travel limits or desired level of comfort based mostly on spring rates, damping and vibration propagation.
Braking, handling, acceleration, motor and transmission performance are all limited by the combined weight limits not payload.
I didn't work for a long time in that area and I never had occasion to address payload limits directly at the time so I never was confronted with the question of how to handle payload limits with WD. Payload limit testing was not performed with heavy trailers attached (vehicles did tow a very small trailer which had test equipment on them).
I have asked old contacts about this and have not gotten a satisfactory answer. Nobody I know seems to know for sure other than what I said earlier which is it depends on the vehicle in question and what limit determined final payload.
I was hoping someone here might know.
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It may be simplistic but my approach is if you can't find it mentioned or explained in the owner's manual or the towing guide, you have to assume the entire tongue weight is subtracted from the cargo capacity, even though you're using a WDH.
If someone is so close to capacity that they have to try to justify the load by discounting the weight shifted by the WDH then they need to rethink the tow vehicle and/or the trailer.
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06-12-2020, 08:21 AM
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#380
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Rivet Master
2018 25' International
Slidell
, Louisiana
Join Date: Sep 2017
Posts: 3,725
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I have been within 40 pounds when I carry some wood and all my heavy cooking gear and this is with a 2500. The diesel and long bed does take 450 lbs that I can't have back. I ask not because I intend to exceed limits, but the question comes up a lot and nobody seems to have a rational answer for it. The common approach to include it is the conservative route. I suppose I'll have to get my slide rule and pencil out and run the dynamics to see what the correct answer it. I suspect the correct answer is there is no correct answer, but we will see.
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