Payload math / weight distribution hitch

[BandLAir]

Most of the weight distribution from a weight distributing hitch will be to the front/steer axle of the truck, with a little to the trailer tires. The Airstream Owners Manual seems to suggest (state) a larger percentage to the trailer, but that is not our experience, and it is not the experience of folks like Sean Woodruff of ProPride, Inc. Your situation might be marginal in terms of your truck. Hitches like the ProPride 3P-1400 put the trailer a bit farther back from the truck than the standard pivoting ball hitch, but I suspect that having your tailgate down would be a problem in tight turns.

[Gene]

Originally Posted by BandLAir

Most of the weight distribution from a weight distributing hitch will be to the front/steer axle of the truck, with a little to the trailer tires.

Correct so far as it goes, but 2/3 to the truck axles and 1/3 to the trailer axles is roughly the number. It can be calculated exactly if you are a physics major. There are hundreds of truck versions and lots of trailers and hitches, so every rig is almost unique and you can adjust each part to some degree. When we had an Equalizer, there were three adjustments on it and so weight transfer could be changed a bit as I adjusted for a level truck, level trailer and level bars, in that order. It is very hard to get it perfect, but you can get close. The hitch we have now has little to adjust and in retrospect I liked the Equalizer better.

Unless you have a testing lab in your garage, it is all a game of estimates. So,me things you can pun down like tow capacity, gross weight, et., but don;t trust Airstreams tongue weights—they do not give accurate numbers—so add several hundred lbs. to whatever they say, Do not listen to any vehicle salesperson about what any part can do because they are salespeople. Always check independently and it is good you looked here for honest answers. Of course honest answers can be wrong too, so you have to analyze them and see what makes the most sense.

People with half ton trucks have to figure this out more carefully. My belief is that mid weight trailers can be towed by some half ton trucks, but some of those trucks are pretty light duty and are more vanity trucks than work trucks. Some brands do not use SAE standards to determine how much they can tow, some do. I would not trust a brand that does not use the SAE standards.

When we were first looking for a trailer, we weighed what we would take in the truck and the trailer. This was tedious, but we really had no idea what things weighed. I think most people underestimate weight because they really want to bring all their favorite stuff. It is best to weigh each vehicle empty and full, but you don't get to borrow a trailer, load it up and take it to a scale.

One of things I have never liked about trailers is that I have to, once we are settled at a campground, driving the full sized truck around to see things. It easier to drive a small or even medium SUV around. I understand your desire to bring your motorcycle. A smaller one may only weigh a few hundred pounds or an electric bike can get you around somewhat. We discussed collapsible bikes but never could figure out where to stow them plus all our other stuff. It is surprising how much stuff can congregate in the truck bed and tools, extra gas, hitch parts, emergency gear, trailer spare tire (easier to stow in there), water and sewer parts, jack for trailer, scrap wood to lift one trailer wheel off ground if necessary, outdoor chairs, extra water and food, wheel chocks, wheel locks, tow chain, compressor for tires, tire repair kit—and even more will end up in the truck, either in the bed, or back seat. If you have a cover—tonneau or topper—or any options not accounted for on the door sticker, more weight. If you remove the back seat, you can save some weight. Amputations or divorce can also lower weight, but is not advised.

We have towed well over 70,000 miles two mid-weight trailers without incident. I am maxed out on the truck, but have so far no problems. Towing does wear brakes, so at around 110,000 miles I did an almost complete rebuild of the brakes (everything new except the rear calipers and brake booster). The truck is now over 130,000 and is like new. If you are careful, you can do it with your truck, but the motorcycle may just be too much. Or, the rig i saw camped in Utah—a Peterbilt towing a trailer toy hauler—they kept a Smart car in the toy hauler section. I wonder how they felt getting into the Smart car after the Peterbilt, especially since they were obese too and the Smart car is really small.

[SailorSam205]

To increase the distance between your TV and trailer safely, get either a Propride or Hensley hitch. Because of the design, both add about a foot to that measurement. I have no problems dropping my tailgate while hitched up.

Also, even though they are heavy hitches, because of the additional length and the laws of levers, your tongue weight will not change much. I have read a number of posts where the increase was +/- 25 lbs. Yes, some folks ended up with lower tongue weights. Propride WD jacks make dialing in your WD really easy.

Main downside to these, they are expensive. Since you have time, watch the want ads. The hitches periodically come up for sale used from folks upgrading to 5th wheels or class A/C and selling the trailer.

There are a couple of really good threads on this site that go over both of these hitches.

[RussellG]

Originally Posted by Gene

Correct so far as it goes, but 2/3 to the truck axles and 1/3 to the trailer axles is roughly the number. It can be calculated exactly if you are a physics major. There are hundreds of truck versions and lots of trailers and hitches, so every rig is almost unique and you can adjust each part to some degree. When we had an Equalizer, there were three adjustments on it and so weight transfer could be changed a bit as I adjusted for a level truck, level trailer and level bars, in that order. It is very hard to get it perfect, but you can get close. The hitch we have now has little to adjust and in retrospect I liked the Equalizer better.

Unless you have a testing lab in your garage, it is all a game of estimates. So,me things you can pun down like tow capacity, gross weight, et., but don;t trust Airstreams tongue weights—they do not give accurate numbers—so add several hundred lbs. to whatever they say, Do not listen to any vehicle salesperson about what any part can do because they are salespeople. Always check independently and it is good you looked here for honest answers. Of course honest answers can be wrong too, so you have to analyze them and see what makes the most sense.

People with half ton trucks have to figure this out more carefully. My belief is that mid weight trailers can be towed by some half ton trucks, but some of those trucks are pretty light duty and are more vanity trucks than work trucks. Some brands do not use SAE standards to determine how much they can tow, some do. I would not trust a brand that does not use the SAE standards.

When we were first looking for a trailer, we weighed what we would take in the truck and the trailer. This was tedious, but we really had no idea what things weighed. I think most people underestimate weight because they really want to bring all their favorite stuff. It is best to weigh each vehicle empty and full, but you don't get to borrow a trailer, load it up and take it to a scale.

One of things I have never liked about trailers is that I have to, once we are settled at a campground, driving the full sized truck around to see things. It easier to drive a small or even medium SUV around. I understand your desire to bring your motorcycle. A smaller one may only weigh a few hundred pounds or an electric bike can get you around somewhat. We discussed collapsible bikes but never could figure out where to stow them plus all our other stuff. It is surprising how much stuff can congregate in the truck bed and tools, extra gas, hitch parts, emergency gear, trailer spare tire (easier to stow in there), water and sewer parts, jack for trailer, scrap wood to lift one trailer wheel off ground if necessary, outdoor chairs, extra water and food, wheel chocks, wheel locks, tow chain, compressor for tires, tire repair kit—and even more will end up in the truck, either in the bed, or back seat. If you have a cover—tonneau or topper—or any options not accounted for on the door sticker, more weight. If you remove the back seat, you can save some weight. Amputations or divorce can also lower weight, but is not advised.

We have towed well over 70,000 miles two mid-weight trailers without incident. I am maxed out on the truck, but have so far no problems. Towing does wear brakes, so at around 110,000 miles I did an almost complete rebuild of the brakes (everything new except the rear calipers and brake booster). The truck is now over 130,000 and is like new. If you are careful, you can do it with your truck, but the motorcycle may just be too much. Or, the rig i saw camped in Utah—a Peterbilt towing a trailer toy hauler—they kept a Smart car in the toy hauler section. I wonder how they felt getting into the Smart car after the Peterbilt, especially since they were obese too and the Smart car is really small.

Thanks for the though reply. The F150 (after the changes of 2015 where they lowered the vehicle weight by about 700 lbs using aluminum panels) can easily handle the 27' AS trailer and "normal" amount of camping gear.

I am decided for the bigger truck though. the Motorcycle (i'm taking this for fun and cruising some amazingly beautiful country, not just for a secondary vehicle, so going from my full size bagger down to an electric bicycle is not my goal). While the math is tight and theoretically doable, the tailgate down is not as it seems with the AS short tongue and jack and propane is very close to the ball. The tailgate off also will not work as It would be unsafe to pull up a ramp into the bed with almost no room for the back wheel to be fully in the truck bed without the front tire hitting the cab. It fits on paper, but only by inches and its not a real world good idea to try to do.

Also, as I intend on traveling for months at a time, I would need to haul extra gear. with my current truck all of that weight would need to be in the trailer and the AS can't handle a bunch of extra weight either.

So, will bite the bullet and get a full crew cab, 8' bed truck I hate to add 2.5 feet to the TV and spend another $75K when my truck only has 50K miles on it and I love it, but it is what it is. The big picture is that I want to be safe to handle more rather than short on supplies and worrying about the situation all the time.

Again with no Motorcycle weighing it down, 10,800 lbs towing and 1,976 payload capacity would be fine.

Thanks for all the responses about the WD hitch effects, this is all great info and will help a lot both now and in the future.

[gypsydad]

Originally Posted by RussellG

Thanks for the though reply. The F150 (after the changes of 2015 where they lowered the vehicle weight by about 700 lbs using aluminum panels) can easily handle the 27' AS trailer and "normal" amount of camping gear.

I am decided for the bigger truck though. the Motorcycle (i'm taking this for fun and cruising some amazingly beautiful country, not just for a secondary vehicle, so going from my full size bagger down to an electric bicycle is not my goal). While the math is tight and theoretically doable, the tailgate down is not as it seems with the AS short tongue and jack and propane is very close to the ball. The tailgate off also will not work as It would be unsafe to pull up a ramp into the bed with almost no room for the back wheel to be fully in the truck bed without the front tire hitting the cab. It fits on paper, but only by inches and its not a real world good idea to try to do.

Also, as I intend on traveling for months at a time, I would need to haul extra gear. with my current truck all of that weight would need to be in the trailer and the AS can't handle a bunch of extra weight either.

So, will bite the bullet and get a full crew cab, 8' bed truck I hate to add 2.5 feet to the TV and spend another $75K when my truck only has 50K miles on it and I love it, but it is what it is. The big picture is that I want to be safe to handle more rather than short on supplies and worrying about the situation all the time.

Again with no Motorcycle weighing it down, 10,800 lbs towing and 1,976 payload capacity would be fine.

Thanks for all the responses about the WD hitch effects, this is all great info and will help a lot both now and in the future.

I think your smart for getting a 1T minimum for your application. The payload of the F150, even a stripped down model, would be marginal with the 27' and your motorcycle, IMHO. A 3/4T has a 6'6' bed, could work, perhaps, but unless you get a strip down model, payload again may be taxed. Better to be safe then sorry if your dead set on bringing along a cruzing bike of 500-800lbs...my HD was 850lbs as I recall...hardly a bike I would consider loading in the back of my F250, but I see some folks doing it with longer bed! You could add a spring on the F250 or get the F350 and be done with it. Better to be safe then sorry after spending the $$ (although, I have been seeing some really great deals on the 2019 model 3/4T models! What ever you get, don't go by the specs on payload...check out the actual truck door jam stickers to get the actual number limits. Let us know what you end up with!

[mpabele]

You could consider having a reputable spring shop install one additional leaf on each side of the rear axle. This would increase payload and assist with weight distribution. While it would not equate to all that would be upgraded by going to a 3/4 ton, it would improve capability of a 1/2 ton.

[sdavis2616]

I am getting ready to retire and have wanted to do the same thing. I have a 3/4ton with a 6.5' bed. I was looking at installing the rampage motorcycle lift and removing my tailgate. The lift will overhang the bumper but I don't believe having the tailgate installed will affect the operation of the lift. The lift may be narrow enough so it doesn't interfere with the turn radius of the trailer. I had planned on cutting plywood for a jig to match the dimensions of the lift and placing it in the back of the truck to see how the turn radius was affected. I didn't get that far because I have decided to upgrade to a truck with an 8' bed. If you stay with the smaller bed you might consider checking out this option. I would think using a 1/2 ton is pushing the limit.

[mkcurtiss]

Originally Posted by RussellG

I am hoping to buy an Airstream trailer in the future and I would like to tow it with my motorcycle in the back of my truck. (if this does not work, I need to find out before I get my trailer) So I can't do a physical example.

My truck, 2016 F150 with 3.5 ecoboost says I have payload of 2,170.

My Motorcycle is 700lbs (with full tank and bags loaded with normal items)
My self and passenger 400 lbs

That leaves me 1,070 pounds for the tongue weight and any other stuff I have in the truck. Also i'm worried about the rear axle load with the bike center of gravity just in front of the rear axle.

Also, I only have 6.5 foot bed, so I would need to drive with tailgate down or off. So I would need to extend the hitch back a little

Questions.
1) Does the tongue weight go down with a weight distribution system? i.e. does it distribute the tongue weight to all the axles including the trailer?

2) If I extend the hitch away from the truck, what does this do to the calculations?

You will need a bigger truck.....If you buy a vintage Airstream, you may be able to squeak by, but even then you will be close...(vintage Airstreams are much lighter than new Airstreams)

[DC Bruce]

Seems like you’ve made the right call in going for the bigger truck. A couple of points:
First, one of the reasons for WD is to restore weight on the steering axle. This is important to retain braking and turning ability in low traction conditions, like rain. Adding air bags or extra leaf springs to the rear axle will eliminate sag but will not shift weight to the steer axle.
Secondly, most people here seem obsessed with Diesel engines, perhaps from the days when gas engines were less capable than they are and diesels were relatively simple and bulletproof. However, the truth is that you suffer a big payload penalty with a diesel because the engine is so much heavier—1,000 lbs or more. So the payload for a RAM 2500 diesel is just a few hundred pounds more than what you say your F-150 is rated for. And there’s the $7000 or so price premium for the diesel motor. Yes. The diesel will give you a few mpg more than the gas motor, but when you factor in the fact that, in most parts of the country, diesel fuel is priced close to the price of premium gasoline you’re never going to make up the extra cost of the truck with fuel savings. Yes, the exhaust brake in a diesel is nice, but consider the fact that the service brakes on your diesel 3/4 ton are having to stop 1,000 more pounds than the same size brakes on a gas powered 3/4 ton. Gas engines do provide engine braking, and the larger displacement of the engine, the more braking they provide. One of the disadvantages of the 3.5 liter Ecoboost engine is that it’s small displacement doesn’t provide much engine braking. I can tell you that my experience with the 6.2 liter gas engine that powers my GMC 1/2 ton is that it provides plenty of engine braking for my FC 27 trailer and a full load of stuff in the bed. We’ve done 4 X-country trips and been all over the Rocky Mountain west, including some pretty insane back road grades that greatly exceed Interstate Highway specs.
The gas engines in all of the 3/4 ton offerings exceed the displacement of my truck’s engine, in some cases by a lot (Ford, GM/Chevy), so I would urge you to consider them for the savings in initial cost and maintenance.

[WestieHouse]

Originally Posted by gypsydad

All good advise...I also had an F150 platinum EB; actual payload on the doorjamb sticker was 600lbs less then the dealer told me it would be during purchase process...Sticker said 1039lbs. I drove for 2 years pulling our 25' AS with Kayaks and a generator, before understanding I was way over payload actual specs for that truck. Not sure what size AS your looking at, but if larger then a 25', you should consider a 3/4T or 1T IMHO... Still not sure about the bike...

We recently purchased an F-150 3.5 EcoBoost with Max Tow package to pull our 25 RBT. We liked the creature comforts on the Platinum trim model but chose the Lariat as a compromise to increase our payload capacity.

Trim models and option packages make a big difference on the payload and thus what B pillar sticker will state. In addition to tow package options other considerations include engine, gear ratio, bed size, can configuration, and 4x4 vs 2 wheel drive. Oh yeah, and the size of your dog (chihuahua or St. Bernard), garage, and budget.

[Gene]

Another alternative is a lighter trailer. There are much lighter trailers made with similar stuff and more storage. We had an Airstream for ten years and it was quite an experience, but the prices are very high the the quality is not all that good. Airstream makes a toy hauler too, but the weights and the rest are unknown to me.

[sctinman44]

Originally Posted by RussellG

I am hoping to buy an Airstream trailer in the future and I would like to tow it with my motorcycle in the back of my truck. (if this does not work, I need to find out before I get my trailer) So I can't do a physical example.

My truck, 2016 F150 with 3.5 ecoboost says I have payload of 2,170.

My Motorcycle is 700lbs (with full tank and bags loaded with normal items)
My self and passenger 400 lbs

That leaves me 1,070 pounds for the tongue weight and any other stuff I have in the truck. Also i'm worried about the rear axle load with the bike center of gravity just in front of the rear axle.

Also, I only have 6.5 foot bed, so I would need to drive with tailgate down or off. So I would need to extend the hitch back a little

Questions.
1) Does the tongue weight go down with a weight distribution system? i.e. does it distribute the tongue weight to all the axles including the trailer?

2) If I extend the hitch away from the truck, what does this do to the calculations?

Have you considered an Eddie Bauer Airstream. It's like a Toy-Hauler. I saw info on a 25ft one. Put kayaks, motorcycles or other outdoor items. I do not know any of the capacity specs, but that might give you an option to keep your current vehicle. Just an idea. Good luck

[KevinFH]

Originally Posted by Gene

Welcome. There are countless threads and posts about calculating weight issues and you would do well to use the search function and do some reading. You will notice a lot of disagreement and some really wrong posts. Learning about this is a challenge.
And you are to be commended for wanting to learn this before you get yourself in a mess.

1. Weight distribution hitches do transfer some tongue weight from the traile axles tot he truck axles. The idea is that the hitch makes the two vehicles one, thus redistributing weight. If the tongue wt. is 1,000 lbs., two thirds (roughly) axles to the truck axles and 1/3 to the trailer axles. So you subtract 667 lbs. from your truck cargo allowance. Also you have to subtract the hitch assembly wt., any extra things mounted at the front of the trailer and any options added to the truck that don't appear on the weight sticker(s) on the truck drivers door frame. Do you have a tune or a truck topper? You will probably find there are lots o/f things you want to have in the truck—tools for example. Airstream don't have a lot of storage, so a truck takes some of the stuff that won't fit. 2,170 lbs. seems like a lot of cargo wt. for a 1/2 ton truck, so check the numbers carefully.

2. You want the tongue to be as close as possible to the truck without compromising the ability to turn the truck (especially backing) and not hit anything like a truck bumper on the tongue. The weight distributing hitch tries to project weight forward to the truck axles plus the closer it is to the rear axle, the more stable the rig is. You can extend a hitch assembly backward with the proper attachments, but you will lose some stability and change the weight calculations. How to quantify this into numbers is for engineers. The more expensive hitches like the Pro Pride do a better job of projecting weight forward and provide stability, but cost several times more. Whether they can be extended further back to give you more space is something to check with hitch manufacturers. My first hitch was an Equalizer and with it I could lower the tailgate all the way. The one I have now does not allow that and I have to rest the tailgate on the tongue and sometimes put something soft on the tongue so I don't damage paint or put a dent in the tailgate. Of course, to load/unload a motorcycle you will have to unhitch anyway.

Note that Airstream hitch weights as stated by the manufacturer are often wrong. I have seen very different weights cited in different Airstream promotional materials, usually less than reality, perhaps by several hundred pounds.

Assuming you are a human, you will probably underestimate what you will carry and overestimate what the rig can hold.

When you do more research, you will find there are people who recommend adding a safety factor of as much as 20% (i.e, derate the cargo capacity of truck by 20%). But SAE several years ago recalibrated tow weights and some manufacturers follow those recommendations and lowered their tow weights, some did not. See if your Ford is SAE rated. Just like some people recommend buying a 3/4 or 1 ton truck or even a Peterbuilt, others will tell you you can tow with a Subaru Brat. The motorcycle certainly complicates your decisions. There are also aftermarket truck modifications like air bags and an extra leaf spring that can help a bit, but you will still have axles and all other running gear made for a lighter weight.

You are right to be concerned about the weight on your rear axle. Also you should check what the weight ratings are on your truck tires. A Vespa weighs a lot less than a motorcycle, but if you have a motorcycle, you probably will not want to be seen on a Vespa. It is a lot easier to use the truck to get around and not worry about bringing a third vehicle with you. Your alternative is a different truck (a possibility many people, including me, have had to deal with when they buy a fairly heavy travel trailer.

Good to do your research and you will spend too many hours scratching your head wondering if you got it right. You also have to decide what trailer you want, what you can afford, what fits your lifestyle and so on. You may have to get a lighter triller than you want, or get a bigger truck, or leave the bike at home, or otherwise have to accept some limits. Everyone has to accept some limits, so you will not be alone.

Speaking of wrong (a typo maybe?) The first sentence in 1. above is wrong. A WD hitch does not transfer weight from tyhe TT axles to the TV. It transfers weight from the tongue to the TT and TV axles. Also, There is no TV spec called "cargo". But payload, which does not apply to towing, is a specification. Get the TV and TT on the scales and verify F&R GAWR.

[RussellG]

Originally Posted by sctinman44

Have you considered an Eddie Bauer Airstream. It's like a Toy-Hauler. I saw info on a 25ft one. Put kayaks, motorcycles or other outdoor items. I do not know any of the capacity specs, but that might give you an option to keep your current vehicle. Just an idea. Good luck

I looked at the new 27 FB with the rear door option. The issue is the opening height is too small to get the bike inside, then the weight would also be rear of the axles which could create sway, and the bike is already a great deal of the total load capacity of the AS.

Its a great option to toss your tents and Kayaks, maybe a small cycle. But not a full size bike.

I have looked at other toy haulers and even building my own from a cargo trailer. But my GF had an air stream in the past, and she loved i so much.

[Gene]

Originally Posted by KevinFH

Speaking of wrong (a typo maybe?) The first sentence in 1. above is wrong. A WD hitch does not transfer weight from tyhe TT axles to the TV. It transfers weight from the tongue to the TT and TV axles. Also, There is no TV spec called "cargo". But payload, which does not apply to towing, is a specification. Get the TV and TT on the scales and verify F&R GAWR.

Cargo and payload are used interchangeably on this Forum and elsewhere. They mean the same thing. For some people trying to explain "payload" is harder than explaining "cargo".

If the trailer is alone, all the weight is on its axles. If hitched without a weight distribution hitch, some gets transferred to the truck, mostly to the rear axle. With weight distribution the rigidity of the setup transfers weight further forward to the front axle so that your headlights are not lighting the sky.

As for typos, we both seem to create them.

Weighing the rig at a scale is a good idea, but not always convenient or realistic. I lived in a county without a scale (the only one closed just before we bought the trailer) and the ones in the next county were often at busy truck stops. To do weighing properly, you should weigh with and without weight distribution, but few people are going to go back to the scale over and over and may have to pay extra for that. So we worked with known numbers and weighed our stuff and figured out what was good for us, the truck and the trailer. It was labor intensive and we had to guess at some things. The biggest problem was Airstream gives wrong numbers for tongue weights and adding a few hundred pounds is a good idea. Once we bought the trailer, I learned after a while the dealer had set up the hitch very badly. So I called the manufacturer and they explained things about the hitch that were not clear from the instructions. It took several hours on a very hot day playing with all the adjustments to get it right. Living in a rural area in Colorado, finding a flat place was difficult too. The hitch had functioned very well even when badly adjusted, but redoing it made it better.

[pmclemore]

Gene's point about a well-adjusted rig "feels" better is valid. Another test you should perform (if you can find a level spot), is to measure and be sure that your rig - truck and trailer are riding level. That is, the front and rear of the truck should be level, and the trailer front and rear should be also.

If this is true, and if you are not overloaded in any way, you should have a sweet towing rig.

Pat

[Dan and Liz]

“If the trailer is alone, all the weight is on its axles.”

Except for what’s on the tongue jack...

[ROBERT CROSS]

Originally Posted by pmclemore

Snip.... That is, the front and rear of the truck should be level, and the trailer front and rear should be also.
If this is true, and if you are not overloaded in any way, you should have a sweet towing rig.

Pat

Not necessarily...our Burb is not level unhitched loaded nor when hitched with a loaded for camping AS.
The front of the TV is low in both instances.
The AS is 1.5" tongue low with the WD set properly.
The WD CAT numbers and/or measurements are more important than perfectly level.
Bob
🇺🇸
TV alone No WD WD set

[laferic]

Hi ..I'm trying to solve for a similar challenge .. i have a 2017 Tundra 5.7L Crew Cap SB, pulling FC 25 FB. Ideally i want to bring a scooter with us ( < 250 lbf).. contemplating the idea of a front bike rack. I did remove back sits, but we do have a camper shell. thoughts?

Thank you!
Eric

[ROBERT CROSS]

Front hitch & rack.

Bob
🇺🇸