Airstream Serenity 27FB tow vehicle specs

[Norm States]

RAM offers the Ram 3.0L EcoDiesel V6 offering 28 mpg highway and 9,200 lb towing. Have no experience with this engine but certainly worth looking into if you think you need a diesel. Agree with the German made ZT 8 speed. Best transmission for this application on the market. Picked up 2 mpg going from the a 6 speed in my 2011 1500 to 8 speed in my 2014 with air ride suspension. Everything else being equal.

[ashrink12]

Originally Posted by Moflash

No problem.
This is where a lot of people make a mistake.
You are only redistributing the load to the front axels of the tv and the tt axels with a wd hitch.The tongue weight remains constant as that hasn't been affected.Read up on the subject it's pretty interesting.


Sent from my iPhone using Airstream Forums

Also not a problem.

Simply reading your AS manual will hopefully keep you from remaining stuck in your poorly understood position of "tongue weight/ hitch weight remains constant and can't be reduced by a WD hitch". You are arguing against the primary purpose of using a weight distributing hitch. Funny that the name weight distribution hitch sorta suggests that weight is being shifted from somewhere to somewhere.

AS are designed/intended to have their excessive tongue weight redistributed(read as partially removed) from the ball of the TV by a weight distributing hitch or some other suspension device that reduces the AS tongue weight when being towed.

AS recommends that the tongue weight when being towed not exceed 10-11% of the total AS weight but yet they build all AS trailer's with an uncorrected tongue weight that is actually equal to or greater than 15% of the total trailer wt.

AS positions their trailer axles such that they intend for you to use a WD hitch or other suspension device to remove excessive trailer tongue wt from your truck hitch. By positioning the AS axles further aft they create a trailer with excessive tongue wt but also one with improved handling characteristics from a longer wheel base. They intend that you will remove some of this excessive trailer tongue weight with a WD hitch or similar device. They do not want you to allow the tongue weight to remain constant or uncorrected by a WD device.

If you insist on believing that truck hitch weight remains constant before and after employing a weight distribution hitch then frankly you will just have to remain stuck in that position. It seems that using a WD hitch to remove excessive weight from your trucks hitch just might not be for you. Whatever you do, don't waste time actually going to a scale and measuring truck tongue weight before/ after applying weight distribution to see that truck hitch weight does not remain constant but in fact becomes redistributed both away from the hitch and away from the truck itself.

If you insist on using the uncorrected AS tongue weight to deduct from a trucks payload capacity, then you will incorrectly add several hundred unnecessary # that are being carried by the AS axels and you can then more easily talk yourself and maybe somebody else into bigger and bigger tow vehicles.

Isn't it funny how everybody seems to like their choice? Aren't discussions fun!

[ashrink12]

Originally Posted by switz

The tongue weight remains where it is. The hitch does not move from it's location.

A weight distribution hitch uses leverage to split the downforce vector present at the weigh point of the hitch so some of the downward pressure is apparently over the front axle, the rear axle and the trailer axles. Releasing the spring's tension and the force returns in totality to the jack point.

Nice try but trailer/truck hitch weight does not remain constant when applying a weight distribution device.

According to Websters weight is the downward force exerted on an object by gravitational forces. Downward force as you nicely explained it is the same as removing weight from the truck/trailer hitch point. Until I dug in to understand this process, I almost allowed myself to think I needed to go out and buy a bigger truck. I even had the Mrs. convinced that we had to buy a bigger and much more expensive truck!

Drat! Just another missed opportunity! I guess that everyone should choose a TV that makes them feel happy! Either more biggerer or not so more biggerer!

[ckottum]

The weight of a bridge remains constant across its length but we build the foundation for it at its ends, because that is where the weight is carried.

cheryl

[larryglarson]

If you had a 200 lb. WD hitch, weight has to change. Some time chick the weight on the front end and the weight on the back end of an empty pickup not hooked up. The tongue weight of my 30 classic is about right to make that equal.

[timhortons]

The Dodge EcoDiesel with the 3.0 at 240HP/420lbs 8spd is rated at 9200lbs towable. It's lower and more stable also.

People here are buying trucks with 20 and 30k lbs tow ratings to tow 6-7klbs trailers.

I don't get it.

[Norm States]

After towing very heavy fifth wheels for 18 yrs. using the RAM Diesels I get a real chuckle seeing a big diesel capable of towing an 18,000 unit towing one that tips the scale at 8,000 lbs. I figure I have the ideal set up for my AS 27' Flying Cloud. The 1500 RAM Hemi combination is excellent.

[switz]

Yesterday our trailer weighed 9,260 pounds without food aboard. It has a GVW of 10,000 pounds. Our combined rig can weigh between 18,000 and 19,000 pounds depending if the two generators and fuel and other wife required necessities are in the truck.......

We take what we want since we can. For our situation, the ¾ ton diesel truck was the ideal tow vehicle. It also did a great job towing our 2013 25FB that weighed 6,950 pounds camping ready.

[aftermath]

Originally Posted by Moflash

No problem.
This is where a lot of people make a mistake.
You are only redistributing the load to the front axels of the tv and the tt axels with a wd hitch.The tongue weight remains constant as that hasn't been affected.Read up on the subject it's pretty interesting.


Sent from my iPhone using Airstream Forums

Forgive me but I continue to have difficulty grasping your main point here. Namely, "The tongue weight remains constant as that hasn't been affected."

I went through the entire weighing process as described in this post.

http://www.airforums.com/forums/f464...ml#post1111379

Here are a couple of my observations. My rear axle was 2680 without the trailer attached. When I dropped the trailer on the ball without WD hooked up it read 3920. So, I am thinking that the tongue weight is 1240.

But wait....with the WD hooked up the rear axle now reads 3780 for a new TW of 1100 so the TW, at least in my mind has changed. I know it hasn't disappeared but it isn't the same as before.

But wait some more......following the formula to calculate the TW namely, ((FA2 + RA2) - (FA3 + RA3) I came up with 880 which is much different than 1240. Please explain the error in my thinking here. It looks like the TW is not constant and has been affected by something.

[Moflash]

Originally Posted by aftermath

Forgive me but I continue to have difficulty grasping your main point here. Namely, "The tongue weight remains constant as that hasn't been affected."

I went through the entire weighing process as described in this post.

http://www.airforums.com/forums/f464...ml#post1111379

Here are a couple of my observations. My rear axle was 2680 without the trailer attached. When I dropped the trailer on the ball without WD hooked up it read 3920. So, I am thinking that the tongue weight is 1240.

But wait....with the WD hooked up the rear axle now reads 3780 for a new TW of 1100 so the TW, at least in my mind has changed. I know it hasn't disappeared but it isn't the same as before.

But wait some more......following the formula to calculate the TW namely, ((FA2 + RA2) - (FA3 + RA3) I came up with 880 which is much different than 1240. Please explain the error in my thinking here. It looks like the TW is not constant and has been affected by something.

OK,Lets try a simple example.
Hook your Airstream to your tow vehicle without a wd hitch.Now lets say your trailers tongue weight is 800lbs for example.Now grab a 10ft 4x4 and place it under the tow vehicles distribution chassis hitch.Now use the 4x4 as a lever and lift the rear of the tow vehicle (you have super human strength).
Now some of the weight that was on the rear axle is transferred to the front axles as you have the rear of the tow vehicle lifted right?As you are holding the rear of the tow vehicle up(super human strength remember) you place the high end of the 4x4 against the Airstream and now the 4x4 (lever) holds the rear of the tow vehicle in place(in the up position).
A few things have now been affected.

1.A percentage of the load on the rear axle has been transferred to the front axle due to you raising the rear of the tv.

2.The downward force on the 4x4 (lever) transfers additional weight to the Airstream axles because it is holding up the rear end of the tow vehicle. Remember the lever effect?

3.Weight is also removed from the tow vehicles weight distribution chassis hitch.Allowing the hitch to hold more weight with a wd hitch because we are pushing up on it. Remember we placed the 4x4 (lever) under it to lift the rear of the tow vehicle and it is still lifted but the Airstream is holding it up.

Now you tell me what is the trailers tongue weight and how did we affect it?
We did not it is constant but....

In some cases the tongue weight of the trailer increases.Why? Remember the down force that was added to the Airstream in order to continue to hold up the tow vehicle? Lever affect remember?

This is how a wd hitch works.

Simple physics get complicated sometimes

[ashrink12]

Originally Posted by Moflash

OK,Lets try a simple example.
Hook your Airstream to your tow vehicle without a wd hitch.Now lets say your trailers tongue weight is 800lbs for example.Now grab a 10ft 4x4 and place it under the tow vehicles distribution chassis hitch.Now use the 4x4 as a lever and lift the rear of the tow vehicle (you have super human strength).
Now some of the weight that was on the rear axle is transferred to the front axles as you have the rear of the tow vehicle lifted right?As you are holding the rear of the tow vehicle up(super human strength remember) you place the high end of the 4x4 against the Airstream and now the 4x4 (lever) holds the rear of the tow vehicle in place(in the up position).
A few things have now been affected.

1.A percentage of the load on the rear axle has been transferred to the front axle due to you raising the rear of the tv.

2.The downward force on the 4x4 (lever) transfers additional weight to the Airstream axles because it is holding up the rear end of the tow vehicle. Remember the lever effect?

3.Weight is also removed from the tow vehicles weight distribution chassis hitch.Allowing the hitch to hold more weight with a wd hitch because we are pushing up on it. Remember we placed the 4x4 (lever) under it to lift the rear of the tow vehicle and it is still lifted but the Airstream is holding it up.

Now you tell me what is the trailers tongue weight and how did we affect it?
We did not it is constant but....

In some cases the tongue weight of the trailer increases.Why? Remember the down force that was added to the Airstream in order to continue to hold up the tow vehicle? Lever affect remember?

This is how a wd hitch works.

Simple physics get complicated sometimes

Wow. This is some real double talk. It's similar to the logical fallacy

"Russian threats are no news and
No news is good news
Therefore, Russian threats are good news

This is a discussion about concerns people have with the adequacy of their TV as regards cargo capacity.

Should I buy a 1/2 ton, 3/4 ton, or larger TV?

Or, will I use up all of my cargo capacity with the AS published tongue weight? (857# for my AS)

To continue to assert that trailer tongue weight remains constant when using a WD hitch is pointlessly misleading.

Of course the weight doesn't evaporate into the ozone when you redistribute it, any more than I can click my heels together 3 times and make my AS disappear.

For the purpose of estimating the adequacy of TV cargo capacity, you should multiply the AS tongue weight by 2/3 or in my case 857 x 2/3 = 574#. This is a good ESTIMATE of how much cargo capacity I'm using up with AS tongue weight. The other 1/3 now lies on the AS axels.

So if I'm estimating how much of my cargo capacity is consumed by AS tongue weight, the only correct estimate is 574#

To assert that AS tongue weight remains constant is both pointless and misleading.

My WD hitch instructions indicate that without the WD bars that the max carrying capacity is 600#. Without redistributing 1/3 of the AS tongue weight to the TV front axle and 1/3 to the AS axle, I am overloading my hitch before I've even added a plastic fork and knife to my AS.

If you're attempting to estimate the adequacy of your TV cargo carrying capacity, use 2/3 of the published AS tongue wt. and add this with the other cargo items.

It's always a good idea to weigh things at a truck scale to insure that you haven't overloaded your TV axles/tires.

Stay tuned next week for "a hamburgers weight remains constant even after it's been consumed" or "a redistributed hamburger is still a hamburger". Plz don't try to sell me the redistributed hamburger as an unchanged constant.

Maybe you should go with more of a matter is neither created nor destroyed type argument?

[aftermath]

Thanks for this but I do understand how the WD hitch works. What I am struggling with is the concept of tongue weight. I will try to explain.

I have read that using one of those sure-line scales is the best way to determine your trailer's tongue weight. This makes perfect sense to me. No truck involved, no hitch just the weight of the tongue on the scale. Now remember your statement about this weight being a constant.

Mine would be over 1200 pounds. When I follow the weighing protocol and determine my tongue weight, I get 880 pounds. I do understand the role of the WD hitch in all of this and it make sense to me but it does contradict much of what has been stated in this thread regarding TW. I "know" that the weight does not disappear, it only gets redistributed, so it must remove some from the hitch and I think that is the point some posters were trying to make.

Specifically, when you have a half ton and the true TW of 1200 pounds will put you over your payload limit. In my case, 880 is much less than 1200 but the 320 pound "savings" here is not accurate because some of that (but not all) has moved to the front axle of the TV. Do you see where people can get confused?

[Moflash]

This is why I no longer tow with a 1/2 ton pickup.I just does not compute no matter how you look at it.Some trailers require a larger capacity truck and that is why they build all different sizes.


Sent from my iPhone using Airstream Forums

[ckottum]

Using a tongue weight scale to determine how much weight is added to the truck when hitched is really not very accurate. Penciling and adding up published numbers is even worse.

Too many factors involved, placement of the scale along the length of the trailer tongue changes the reading, weight distribution hitch effectiveness, is the trailer dead level when weighed alone and weighed attached and weight distribution applied, position of the travel gear in the truck and the trailer, tank liquids. To name a few.

The only way to know is with the fully loaded truck weighed separately, and then the loaded truck weighed again (truck only on the scale), trailer hitched to it with weight distribution applied. Both times trailer dead level. The difference in truck weight is how much weight is added to the truck.

It doesn't have to end there. If overloaded (primary concern is axle and tire ratings but that's another argument) you can reevaluate gear actually needed, reposition gear in the trailer and reposition, remove, or replace Airstream accessories and equipment with lighter equipment.

Airstreamers tow with vehicles of all sizes and style, and most are safe and happy doing it. Each owner has different needs and preferences. But don't give up because someone tells you the numbers don't add up on paper.

Spend some time learning how to set it up properly or enlist someone who can. Spend some money on the best hitch equipment you can get.

cheryl

[1Boyscout]

Wish you good luck on your new 27 RB IS., I tow with a 1500HD Chevy, 6L, 373, CC, w/Michelin tires. I get 11.5 mpg in Tx and OK. Pulls like a dream, I will not buy another SOB TT. No rubber roof, steps lower to ground, easier to keep clean, much better resale value than a Class C or SOB TT. We decided we did not need to take the whole house with us.

[ashrink12]

TV preferences are often about the AS owner's personality. If you are thoughtful about how you use your AS there are a wide array of TV choices that work really well.

Many 1/2 ton trucks with tow packages are well suited as are 3/4 tons or larger.

Good luck in your search. There are lots of great options to choose from!

Greg

[Rocinante]

Hmm... OP hasn't been heard from since post #22.

Anyway, arguing aside about how many angels can stand on a trailer tongue, we've had good experiences towing our 2014 International Signature 27FB with our Ram 1500.

However, if we had it to do over again, we probably have gone with a 3/4 ton just for load capacity. With our current configuration, due to the heavier-than-specified AS tongue weight, we keep the front of the trailer as light as we can and don't carry much in the bed of the truck. It would be nice if we didn't have to mess with that.

Your mileage may vary. Do what you like, like what you do.

[Arcticfox]

Originally Posted by ckottum

Using a tongue weight scale to determine how much weight is added to the truck when hitched is really not very accurate. Penciling and adding up published numbers is even worse.

Too many factors involved, placement of the scale along the length of the trailer tongue changes the reading, weight distribution hitch effectiveness, is the trailer dead level when weighed alone and weighed attached and weight distribution applied, position of the travel gear in the truck and the trailer, tank liquids. To name a few.

The only way to know is with the fully loaded truck weighed separately, and then the loaded truck weighed again (truck only on the scale), trailer hitched to it with weight distribution applied. Both times trailer dead level. The difference in truck weight is how much weight is added to the truck.

It doesn't have to end there. If overloaded (primary concern is axle and tire ratings but that's another argument) you can reevaluate gear actually needed, reposition gear in the trailer and reposition, remove, or replace Airstream accessories and equipment with lighter equipment.

Airstreamers tow with vehicles of all sizes and style, and most are safe and happy doing it. Each owner has different needs and preferences. But don't give up because someone tells you the numbers don't add up on paper.

Spend some time learning how to set it up properly or enlist someone who can. Spend some money on the best hitch equipment you can get.

cheryl

Well written logical post - well done!
Thanks

Doug

[ashrink12]

Originally Posted by aftermath

Thanks for this but I do understand how the WD hitch works. What I am struggling with is the concept of tongue weight. I will try to explain.

I have read that using one of those sure-line scales is the best way to determine your trailer's tongue weight. This makes perfect sense to me. No truck involved, no hitch just the weight of the tongue on the scale. Now remember your statement about this weight being a constant.

Mine would be over 1200 pounds. When I follow the weighing protocol and determine my tongue weight, I get 880 pounds. I do understand the role of the WD hitch in all of this and it make sense to me but it does contradict much of what has been stated in this thread regarding TW. I "know" that the weight does not disappear, it only gets redistributed, so it must remove some from the hitch and I think that is the point some posters were trying to make.

Specifically, when you have a half ton and the true TW of 1200 pounds will put you over your payload limit. In my case, 880 is much less than 1200 but the 320 pound "savings" here is not accurate because some of that (but not all) has moved to the front axle of the TV. Do you see where people can get confused?

I does seem confusing at times.

When I was trying to wrap my head around the principles of AS tongue weight redistribution, I initially believed that I was overloading my TV and I was prepared to buy a TV that would tow a bulldozer or 2. (My wife continues to refuse me my own bulldozer. Go figure!)

In my AS manual they have a sketch of a TV with an AS hooked up to it. They label the TV front axle as 1/3, the TV rear axle as 1/3 and the AS axle as 1/3. Each of these 3 identified load points is designed to carry 1/3 of the AS tongue weight when your WD hitch is properly installed and setup.

So in your example with an AS tongue weight of 1200#, the redistributed tongue weight using WD bars will equal 400 additional # to the TV front axle, 400 # to the TV rear axle, and 400# to the AS axles. Add the 3 together and this is what happened to the original 1200# of AS tongue weight.

Cheryl correctly directs you to consider a variety of other factors to help determine if you're overloading your TV cargo capacity.

Weight redistribution as depicted in the AS manual is only intended to provide an ESTIMATE of cargo capacity used by your AS tongue weight. The ultimate test is to go to the scales and weigh your rig.

It's possible to load your AS improperly, your TV improperly, and setup your WD hitch improperly to create a dangerous situation regardless of the towing capacity/cargo capacity of your selected TV. If you are careless with good towing principles, then the size of the tow vehicle quickly becomes irrelevant.

Good luck and have fun!

Greg