Different Tongue Weights same size trailers 28' vs 27'

[Vitaminsea]

Hi streamers,

I was researching tow weights and hitches but confused on the big difference of hitch weight (tongue, nose, pin) between the 27Fb model verses the 28. That is 770 pounds verses 950 pounds respectively. Both the same size and with the same gross vehicle rating at 7600 pounds. The 28 is one inch shorter in length strangely.

Is it the bedroom switch? Plus the kichen? The tanks and batteries are all in the same places. The bedroom is heavy too.


Any thoughts most appreciated.

[dkottum]

Those are empty weights. The beds are a very large storage area, the 27FB will probably load heavier in front than the rear bed 28. The loaded tongue weights may be much closer.

[Vitaminsea]

Thanks for that. Didn't think about the airstream posted weights as empty figures and how much that would effect hitch weight. I've stocked my storage compartments, drive with full fresh water, and have food in the frig. I weighed my tougue and it's 850 (or less) verses the 950 airstream posts for the 28'. Now it makes sense. Thanks again.

Monica & JT

[Alphonse]

The 28 footers are one of the heaviest from a tongue weight perspective. It has to do with layout and furnishing. Yes, the tongue weights from the factory specs are a bit confusing, close but will not win the prize. The only way to know what you really have is to weigh it. The water tank is between the axles and when full can help reduce the tongue weight by a bit. The frig is also over the axles and doesn't impact the tongue weight too much. Of course, cargo loading in the rear of the trailer also helps reduce the tongue weight. The 28 Flying Cloud goes over a thousand pounds if you aren't careful with the loading. The 28 International may have an advantage over the FC since the design of the booth is much lighter and the overhead cabinets are fewer and a bit lighter as compared to a Flying Cloud.

[m.hony]

What Alphonse said-
The distance from coupler to axles figures into the equation as well.

[switz]

Camping ready, our 2013 25FB International Serenity had a 1,175 pound tongue weight (literature tongue weight of 833 pounds). We had a Hensley hitch installed.

[Alphonse]

Originally Posted by switz

Camping ready, our 2013 25FB International Serenity had a 1,175 pound tongue weight (literature tongue weight of 833 pounds). We had a Hensley hitch installed.

Switz,
Interesting that you count the Hensley as tongue weight! Many wish to ignore that.
Thanks

[dkottum]

Originally Posted by m.hony

What Alphonse said-
The distance from coupler to axles figures into the equation as well.

Absolutely. Forum posted tongue weights of similar Airstreams can vary widely depending on the position along the tongue the scale is placed. For example the scale placed under the tongue jack will indicate higher tongue weight than a scale placed under the coupler.

[SteveH]

Originally Posted by dkottum

Absolutely. Forum posted tongue weights of similar Airstreams can vary widely depending on the position along the tongue the scale is placed. For example the scale placed under the tongue jack will indicate higher tongue weight than a scale placed under the coupler.

Yes, I've actually weighed mine at the jack, and then again at the coupler, and the difference was more than 100lbs. Seems all of the Airstreams are heavier on the tongue than stated in the literature, and that's probably because of the propane and batteries, but may also be stated on the light side for marketing purposes. It's really not a big deal, just adjust the WD hitch as needed.

At a rally a while back after I had bought my scale, we went around weighing all the tongue weights, and the heaviest in our unit was a 2000 34' SO with the long couch slide, and it weighed over 1300 pounds.

[JFScheck]

As stated by "Sean" (Big Kahuna at ProPride), the Hitch head and mechanism as mounted on the trailer do add to the tongue weight of the setup!

[m.hony]

I agree with a couple of statements here.
1. You must include the weight of the hitch head. It is there- hanging off the receiver- you can't ignore it.
2. Accurate tongue weight should be Measured at the coupler as that is the part that sits on the ball/hitch head/receiver/truck axle...
3. To add to all of that, if I am exceeding 1,000# tongue weight the truck doesn't seem to know or is not bothered by that fact. The weight distributing hitch may make tongue weight a little less because it is designed to transfer some weight to the tow vehicle front axle and trailer axle.
How does one measure tongue weight with weight distributing hitch on? Cat scales? Can it be determined with total combination weight, steer axle weight, drive axle weight, and trailer axle weight? Or is the only way to unhook and get another reading? but this would be on the jack...not the coupler...

[Alphonse]

Originally Posted by m.hony

. . . . . .
3. To add to all of that, if I am exceeding 1,000# tongue weight the truck doesn't seem to know or is not bothered by that fact. The weight distributing hitch may make tongue weight a little less because it is designed to transfer some weight to the tow vehicle front axle and trailer axle.
How does one measure tongue weight with weight distributing hitch on? Cat scales? Can it be determined with total combination weight, steer axle weight, drive axle weight, and trailer axle weight? Or is the only way to unhook and get another reading? but this would be on the jack...not the coupler...

Yes, a WDH does move some tongue weight to the front axle of the truck and a little to the trailer axles. These transferred axle loads do not miraculously eliminate the tongue weight from being a concern however. The applied tongue weight relies on the strength of the receiver hitch to translate the moments and forces into vehicle and the trailer. This is where the capacity of the hitch receiver must be adequate for the service and why they are typically rated for "tongue weight with a weight distributing hitch". Their capacity is not stated as rear axle weight after weight distribution.

Tongue weight can be measured directly using a Sherline scale. The Cat scale tickets can also give you enough data to calculate tongue weight by removing or unloading the weight distribution bars and weighing the TV and Trailer in this condition (w/o weight distribution) as compared to the TV alone.

[m.hony]

I know I am at or near or exceeding tongue weight capacity, but it is really a moot point.
I ain't buying another truck...
I will run what I brung...
If I am at or exceeding buy just a few pounds all is surely OK.
It would be a different story if I were several hundred pounds overweight- like stuff would most likely start braking and failing-
So far, so good in 4 years and 25,000 miles-

[Alphonse]

m.hony, Sorry, I did not intend to infer the choice is not yours.

[m.hony]

I didn't take it that way at all-
Just sayin'-
If I didn't already have a truck and was making the decision now it might have a different outcome.
I wouldn't advise anyone with a low mileage paid for 1/2 truck to go in debt or spend money for another truck, but if someone didn't already own a 1/2 ton truck the viewpoint/outlook would be different- like maybe I would get a 3/4 GM or Ram-
I am just curious about actual tongue weight on my particular rig- not that I'm gonna change anything or do anything with that number other than file it away with all the other trivial knowledge floating around between my 2 ears...

[Vitaminsea]

I measured the tongue weight at the coupler (where the ball connects) with a scale made for this. It was 850 pounds with the trailer loaded with all our usual gear and full fresh water. That is 100 pounds lighter than the posted 950 pounds listed on the airstream specs. I gather that all the gear, tools, and supplies in the rear compartment, bed side closets, and under the bed make the rear heavier and lighten the front. I never did measure the tongue weight completely unloaded.

My hitch and weight distribution bars are around 40 pounds. Also, if I measured weight at the front jack it was about 100 pounds less than the tongue. Amazing what a short distance in leverage makes on weight.

[dkottum]

It's good to know your normal camping load tongue weight with the scale under the coupler, so you know what the tow vehicle receiver is carrying and what size weight distribution bars to get.

[gmw photos]

Originally Posted by m.hony

....snip....
How does one measure tongue weight with weight distributing hitch on? Cat scales? Can it be determined with total combination weight, steer axle weight, drive axle weight, and trailer axle weight? Or is the only way to unhook and get another reading? but this would be on the jack...not the coupler...

m.hony,
This discussion has been going on also over in another thread:

http://www.airforums.com/forums/f238...ml#post1417653

[Ron Gratz]

Originally Posted by m.hony

How does one measure tongue weight with weight distributing hitch on? Cat scales? Can it be determined with total combination weight, steer axle weight, drive axle weight, and trailer axle weight? Or is the only way to unhook and get another reading? but this would be on the jack...not the coupler...

You can get an approximation of the TW by:
1) measuring the TV's axle loads with the TT unhitched, but with the WDH in the receiver and the WD bars in the rear of the TV.
2) measure the TV's axle loads with the TT hitched, but without installing the WD bars.

The combined axle load from 2) minus the combined load from 1) gives the approximate TW.
If the TT has two axles with independent suspension and the TT is in a nose-down attitude during the second weighing, the difference of 2) minus 1) will be less than the actual TW.
Measuring the actual TW requires a level TT. When a TT with independent suspension is nose-down, more load is carried by the front axle and less load by the rear axle. This causes the load measured at the coupler to be less than the TW.

Another approximate measure of TW can be obtained by having the tongue jack on one scale pad and the TT's axles on another pad with the TT level. The load under the jack will be greater than the TW because the jack is closer to the axles than is the coupler.
The TW is equal to the jack load multiplied by the ratio of d1/d2, where d1 is distance from jack to axles' center and d2 is distance from coupler to axles' center.
For example, if jack load = 800#, d1= 190", and d2 = 200"
then TW = 800*(190/200) = 760#.

Ron

[Airstreamer67]

Quote from post 16: "Also, if I measured weight at the front jack it was about 100 pounds less than the tongue. Amazing what a short distance in leverage makes on weight."

Is this statement reversed? Usually it is noted the jack shows more weight than the tongue.