Weight Distribution and Sway Control -Obsolete for a Self Propelled Trailers?

[Rory (Lightship Team)]

However, keep in mind for example a typical class III hitch ordinarily found on 1/2 ton trucks would have two hitch weight limitations. One is standard tongue weight/weight carrying( WC) 500 lbs and the other is tongue weight with a WDH/ weight distribution( WD) 800 lbs. Additionally and this is where folks can become animated, that same hitch with a WDH goes from a 5k to an 8k. ** attributed to leveraging weight ( downward force) off the hitch and rear frame (stress) of the TV.

yea our Rivian R1T came stock with a Class V hitch.

 

[Obsessed2findARuggedHybid]

However, keep in mind for example a typical class III hitch ordinarily found on 1/2 ton trucks would have two hitch weight limitations. One is standard tongue weight/weight carrying( WC) 500 lbs and the other is tongue weight with a WDH/ weight distribution( WD) 800 lbs. Additionally and this is where folks can become animated, that same hitch with a WDH goes from a 5k to an 8k. ** attributed to leveraging weight ( downward force) off the hitch and rear frame (stress) of the TV.

Gotcha. I believe some 1/2 tons jump from 500 to over 1,000 lbs. That is a huge jump. It almost seems like this whole thread should be separated by WDH and a WDH with sway bars. This lightship is very aero, less then 7 feet tall with 820 pounds of tongue weight. I wouldn't think sway would even be a concern and an electric sway control should be all you need. This all circles back to my new start up. "Electro-TI-EASY-WDH " Inc. by the Dude

 

[turbopilot]

This lightship is very aero, less then 7 feet tall with 820 pounds of tongue weight. I wouldn't think sway would even be a concern and an electric sway control should be all you need.

And after three pages of posts in this thread that was exactly the thought I included in the original post in this thread.

So what does this all mean? My initial driving experience with the LightShip suggests to me that it is very possible the LightShip does not need a supplemental sway control device. But what about weight distribution?

I left the issue of weight distribution as an open question in the OP, subject to a lot more experience towing the LightShip, which hopefully will happen soon. But as others have clearly discerned I am skeptical about the need for weight distribution, for my use case.

Let me be clear my first experience towing the LightShip prototype was with my tow vehicle (an F-150 Platinum PowerBoost). All of my opinions are centered around a LightShip being towed with my tow vehicle. I am not rendering any opinions about the LightShip being towed by other tow vehicles.

I have been towing a 2022 Airstream Globetrotter (25') with an F-150 PowerBoost since 2021. I probably have in excess of 30,000 miles experience, to date, with this combination. The PowerBoost GVWR is 7,300 lbs. The Airstream GVWR is 7,300 lbs with a hitch weight of 836 lbs. Typical use case is that both the PowerBoost and the Airstream are operated nominally at the full GVWR. For this situation combination I use a 114 lb B&W Continuum WDH that incorporates both WDW and excellent sway control in the same device.

But here is the surprise. That 114 lb B&W Continuum hitch when set up to Ford's 50% FALR specification returns only 181 lbs to the front axle. So you are putting 114 lbs on the rear of the F-150 in order to move 181 lbs off the rear axles to the front axles. For a 7,300 lb pickup is that additional 181 lbs really worth all the extra cost, weight and inconvenience of using a WDH? That is a question not a conclusion.

Now consider the LightShip being towed by the same PowerBoost. The LightShip weighs 1,000 lbs more fully loaded but it has nearly the same hitch weight. So from the tow vehicle's standpoint the same numbers apply, you add 114 lbs of WDH hardware to the rear of the PowerBoost in order to shift 181 lbs from the rear axle to the front axle.

Manufacturers set the FALR for their vehicles to optimize the understeer associated with towing a trailer and that adds weight on the hitch. Ford sets the FALR at 50% for their pickups. So the question to be answered is how much difference is adding 181 lbs to the front axle is going to make when towing a CGWVR of 14,600 lbs in the case of the Airstream or 15,600 lbs in the case of a LightShip.

I do not have the answer. I am posing a question. But for this particular combination of a towable and a tow vehicle, I am skeptical that the pain is worth the gain.

The B&W Continuum WDH has some strong anti sway qualities that is helpful with the Airstream, so I think the that WDH made sense towing the Airstream for the anti sway attributes. But the LightShip is going to be much more resistant to sway and it is being towed by a PowerBoost with a built in trailer anti-sway system.

So for my use case, where a sway control device may not be important, does it make sense to put a heavy device on the rear of the truck to return 181 lbs to the front axle?

And now here is the data to support my off the wall speculation. This spreadsheet represents the actual four corner weights associated with my F-150 PowerBoost set up to tow the 25' Airstream using a WDH set to 50% FALR. From the standpoint of weight distribution on the hitch the numbers will be the same for a LightShip.

 

[Obsessed2findARuggedHybid]

And after three pages of posts in this thread that was exactly the thought I included in the original post in this thread.


I left the issue of weight distribution as an open question in the OP, subject to a lot more experience towing the LightShip, which hopefully will happen soon. But as others have clearly discerned I am skeptical about the need for weight distribution, for my use case.

Let me be clear my first experience towing the LightShip prototype was with my tow vehicle (an F-150 Platinum PowerBoost). All of my opinions are centered around a LightShip being towed with my tow vehicle. I am not rendering any opinions about the LightShip being towed by other tow vehicles.

I have been towing a 2022 Airstream Globetrotter (25') with an F-150 PowerBoost since 2021. I probably have in excess of 30,000 miles experience, to date, with this combination. The PowerBoost GVWR is 7,300 lbs. The Airstream GVWR is 7,300 lbs with a hitch weight of 836 lbs. Typical use case is that both the PowerBoost and the Airstream are operated nominally at the full GVWR. For this situation combination I use a 114 lb B&W Continuum WDH that incorporates both WDW and excellent sway control in the same device.

But here is the surprise. That 114 lb B&W Continuum hitch when set up to Ford's 50% FALR specification returns only 181 lbs to the front axle. So you are putting 114 lbs on the rear of the F-150 in order to move 181 lbs off the rear axles to the front axles. For a 7,300 lb pickup is that additional 181 lbs really worth all the extra cost, weight and inconvenience of using a WDH? That is a question not a conclusion.

Now consider the LightShip being towed by the same PowerBoost. The LightShip weighs 1,000 lbs more fully loaded but it has nearly the same hitch weight. So from the tow vehicle's standpoint the same numbers apply, you add 114 lbs of WDH hardware to the rear of the PowerBoost in order to shift 181 lbs from the rear axle to the front axle.

Manufacturers set the FALR for their vehicles to optimize the understeer associated with towing a trailer and that adds weight on the hitch. Ford sets the FALR at 50% for their pickups. So the question to be answered is how much difference is adding 181 lbs to the front axle is going to make when towing a CGWVR of 14,600 lbs in the case of the Airstream or 15,600 lbs in the case of a LightShip.

I do not have the answer. I am posing a question. But for this particular combination of a towable and a tow vehicle, I am skeptical that the pain is worth the gain.

The B&W Continuum WDH has some strong anti sway qualities that is helpful with the Airstream, so I think the that WDH made sense towing the Airstream for the anti sway attributes. But the LightShip is going to be much more resistant to sway and it is being towed by a PowerBoost with a built in trailer anti-sway system.

So for my use case, where a sway control device may not be important, does it make sense to put a heavy device on the rear of the truck to return 181 lbs to the front axle?

And now here is the data to support my off the wall speculation. This spreadsheet represents the actual four corner weights associated with my F-150 PowerBoost set up to tow the 25' Airstream using a WDH set to 50% FALR. From the standpoint of weight distribution on the hitch the numbers will be the same for a LightShip.


View attachment 31107

I forget is your wdh the same as the one LightShip includes? Is thier a lighter one. Maybe the Anderson with chains ?

 

[turbopilot]

I forget is your wdh the same as the one LightShip includes? Is thier a lighter one. Maybe the Anderson with chains ?

Curt 17025 weighs 84 lbs without the sway control option. And it is the "chain and bar" type system. The Curt 17025 is a real bear to setup with each hook up.

 

[Obsessed2findARuggedHybid]

Curt 17025 weighs 84 lbs without the sway control option. And it is the "chain and bar" type system. The Curt 17025 is a real bear to setup with each hook up.

Well I guess the answer to your question is will Ford and other 1/2 ton truck makers ever change the dead weight tongue capacity for trailers like LightShip? Until they do for liability reasons rolling down the highway with out wdh in a near $300k truck and trailer is not something I would risk. But I have the worst karma known to man. Not that this current LightShip would really be used off road but WDH are not ideal for off-road use. The answer may also be if you don't want to deal with a wdh and or drive off road with a trailer with 820 lbs of tongue weight you need a 3/4 ton truck. Or dont worry about liability.

 

[turbopilot]

Well I guess the answer to your question is will Ford and other 1/2 ton truck makers ever change the dead weight tongue capacity

There was an interesting thread on another forum about the logic of this guideline. Conventional wisdom was it made no engineering sense but was simply a short cut to make an owner use a WDH for heavier trailers.

 

[Obsessed2findARuggedHybid]

There was an interesting thread on another forum about the logic of this guideline. Conventional wisdom was it made no engineering sense but was simply a short cut to make an owner use a WDH for heavier trailers.

Hard saying not knowing. Maybe a conspiracy by the WDH manufacturers? Being an off road trailer guy I have never used one. They look like something out of a torcher chamber. I understand your reluctantly to have to deal with one. Might not be a popular statement on this thread but maybe LightShip, Pebble and the other beast with a stinking ICE generator could get together and build a lighter easier to use WDH.

 

[turbopilot]

Might not be a popular statement on this thread but maybe LightShip, Pebble and the other beat with a stinking ICE generator could get together and build a lighter easier to use WDH.

Or simply compute the weight needed over your front axle to achieve the FALR goal, then bolt some lead bars to your front bumper any time you tow.

In my case a lead bar measuring 2" X 6" X 36" would add 180 lbs to my front bumper which would give me 50% FALR. Nothing to mess with when hitching up the trailer.

Of interest, Pebble Flow does not recommend a WDH with a 700 lb hitch weight.

 

[Obsessed2findARuggedHybid]

Or simply compute the weight needed over your front axle to achieve the FALR goal, then bolt some lead bars to your front bumper any time you tow.

In my case a lead bar measuring 2" X 6" X 36" would add 180 lbs to my front bumper which would give me 50% FALR. Nothing to mess with when hitching up the trailer.

Of interest, Pebble Flow does not recommend a WDH with a 700 lb hitch weight.

Could be that the silcone valley Tesla tech bros don't have a ton of experience crawling around in the mud hitching up a wdh. Kudos to LightShip. I was thinking the problem with a off road model of this type of trailer is to much ground clearance would kill the aerodynamics. But with light ship being a pop up maybe they could build a model with 20" of ground clearance, 21 feet long , computer controlled air oil suspension that has road mode and off road mode, articulating hitch with 500 pounds of tongue weight. That would be my dream rig.

Update: opps I guess LightShip guys are tech bros from Tesla as well. At least thier based in CO. That gives them more street (or dirt in the case) cred.