Air Bags for Weight Distributing ??

[dsjohns71]

Another option is to get some air bags in the rear of truck. I would definitely get a WD Hitch without the chains. I have the FASTWAY hitch made by EQUALIZER and I love it. I have just over 900 lbs on my tongue with a 31' TT...

[MtnGuy]

Originally Posted by dsjohns71

Another option is to get some air bags in the rear of truck.

How does the affect weight distributing and trailer sway ??

[OldCoot]

Originally Posted by MtnGuy

...How does the affect weight distributing and trailer sway ??

By raising the rear of the truck which will automatically put more wt on the front.

[MtnGuy]

Originally Posted by OldCoot

By raising the rear of the truck which will automatically put more wt on the front.

Huh ??

You are saying that by raising the rear of a truck, that distributes more of the trailer tongue weight to the front of the truck ?? How could that be, and just how much weight would it transfer if it is indeed possible ??

Raising the pivot point (rear axle) does nothing to distribute trailer tongue weight to the front axles, unless it would be the tiny sliver of truck above the axle that is moved in front of the axle by raising the truck.

[caper]

Huh ??

You are saying that by raising the rear of a truck, that distributes more of the trailer tongue weight to the front of the truck ?? How could that be, and just how much weight would it transfer if it is indeed possible ??

Raising the pivot point (rear axle) does nothing to distribute trailer tongue weight to the front axles, unless it would be the tiny sliver of truck above the axle that is moved in front of the axle by raising the truck.

If you are on a set of scales and you raise the rear of the truck you will find that the front of the truck will get heavier. Therefore you are transferring weight from the back to the front. Think of it this way total truck weight is 7000 lbs. When rear end low front of truck will come up (less weight on tires). So front weight could be 2800 lbs and rear weight is 4200 lbs. Raise rear front weight changes to 3200 lbs and rear weight is 3800 lbs.

[OldCoot]

Originally Posted by MtnGuy

Huh ??

You are saying that by raising the rear of a truck, that distributes more of the trailer tongue weight to the front of the truck ?? How could that be, and just how much weight would it transfer if it is indeed possible ??

Raising the pivot point (rear axle) does nothing to distribute trailer tongue weight to the front axles, unless it would be the tiny sliver of truck above the axle that is moved in front of the axle by raising the truck.

It also raises the wdh hitch, therefore increasing the wt transfer, but I will bow to your expertise as what I've actually experienced was all imaginary. Have a nice summer.

[Brother Les]

Originally Posted by MtnGuy

Huh ??

You are saying that by raising the rear of a truck, that distributes more of the trailer tongue weight to the front of the truck ?? How could that be, and just how much weight would it transfer if it is indeed possible ??

Raising the pivot point (rear axle) does nothing to distribute trailer tongue weight to the front axles, unless it would be the tiny sliver of truck above the axle that is moved in front of the axle by raising the truck.

Your kidding right? This is why the the hitch is called a "Weight Distributing Hitch".

This is how Herk has explained it.

http://www.forestriverforums.com/for...rks-21385.html

[MtnGuy]

In defense of my previous posts, he is a synopsis of this thread, which was spun off of a sister thread to keep that thread on topic.

In post #3, OC posted to my question (post #2) on “How does that affect weight distributing and trailer sway ??” in my question to post #1 "Another option is to get some air bags in the rear of truck." regarding sway control and weight distributing from the sister thread.

Originally Posted by OldCoot

By raising the rear of the truck which will automatically put more wt on the front.

My reply in post #4:

“Huh" ??

You are saying that by raising the rear of a truck, that distributes more of the trailer tongue weight to the front of the truck ?? How could that be, and just how much weight would it transfer if it is indeed possible ??

Raising the pivot point (rear axle) does nothing to distribute trailer tongue weight to the front axles, unless it would be the tiny sliver of truck above the axle that is moved in front of the axle by raising the truck."

So far, there has been no mention of using WDH in the replies.

Not sure what Post #5 refers to, whether just air bags or a WDH.

In post #6, OC responds to my post #4:

"It also raises the wdh hitch, therefore increasing the wt transfer, but I will bow to your expertise as what I've actually experienced was all imaginary. Have a nice summer."

With that post, now a WDH is introduced into the mix. A WDH was mentioned in the 1st post, but my original in question in post #2 was only about air bags.

So now, let’s talk about raising the rear of a truck with air bags while using a WDH. Raising the rear of a tow vehicle while using a WDH will actually take weight off of the front axle of the tow vehicle. That is why we need to need to raise the rear of the truck with the tongue trailer tongue jack to get the spring bars in place…..it relieves the tension on the spring bars. Going through a dip causes more weight to be distributed to the tow vehicle front axle. Going over a hill in the road will take weight off of the front axle……..the same geometry as raising the rear end with air bags while using a WDH.

Brother Les’ post #7 response to my post #5 refers to a WDH, while I was referring to air bags.

Confused yet ??

[goduc]

I this logic goes hand in had with the mpg logic I've heard before. You know, if you drive faster you aren't in the car as long so you won't use as much gas.


I can't wait for the breakdown of how lifting the rear of the truck transfers weight to the front. If you air bags up on the rear to 25psi on an empty truck, yes the rear will raise. So noiw you drop the TT tongue on the WD and it acts like a lever and raises the front of the truck. So do you then add more air? How much air do you add to regain the front weight you lost by placing the coupler on the WD?


So If I measure the front of the truck empty with no TT hitched. Then hitch up sans spring bars and measure again. Now I need to be close to the unhitched number to be setup right. So no need for spring bars right? Just start airing up the bags till the front of the truck is close to its original number. Have I got it right?


So what about the receiver rating that says 500-600lbs without WD? Am I exempt from that? This is confusing. So the airbags take the place of WD for weight transfer but not for the receivers rating?


It would be much simpler if they would just put receivers on trucks that would work with 500-1400lb TW's. Then we could just get airbags to level everything up. Way, way cheaper.


All airbags do is raise the pivot point. When you hitch up the TT the front will still unload the same. Airbags don't have any leverage like spring bars do.

[OldCoot]

goduc,MtnGuy, no one said anything about unhooking the wdh while adding air to the air bags.

I will pose this question to you both. WITH the wdh hooked up and assume that raised the front of the truck 1/2" from normal and it took 200 # off the front and by adding air to the bags, you got the front back down the 1/2", where would the 200# go?

[goduc]

Not sure why you even need air bags for 1/2" of front end rise. Another washer or link on the chain would do it. Under your theory then why even use a WD. Why not just hook up without WD and air it up till the front drops to where it needs too. I bet you can't.


What you're doing is in small terms. No way can you load 8-900lbs on the rear of a truck and raise the rear and drop the front back to normal. You certainly aren't transferring any weight to the TT like that.


Under your theory WD is not needed. Just more air. I find it hard to believe that all thru the years of towing when both WD and bags are available that no one has ever said take your pick. Or you can achieve the same results with both.


Also if you are using a WD with built in friction bars then you are lessening the friction when airing up the bags.

[OldCoot]

Originally Posted by goduc

Not sure why you even need air bags for 1/2" of front end rise. Another washer or link on the chain would do it. Under your theory then why even use a WD. Why not just hook up without WD and air it up till the front drops to where it needs too. I bet you can't.


What you're doing is in small terms. No way can you load 8-900lbs on the rear of a truck and raise the rear and drop the front back to normal. You certainly aren't transferring any weight to the TT like that.


Under your theory WD is not needed. Just more air. I find it hard to believe that all thru the years of towing when both WD and bags are available that no one has ever said take your pick. Or you can achieve the same results with both.


Also if you are using a WD with built in friction bars then you are lessening the friction when airing up the bags.

You don't seem to grasp the fact that I do not mention unhooking or not using a wdh. In my question, where does the 200# go?

[dsjohns71]

Originally Posted by OldCoot

You don't seem to grasp the fact that I do not mention unhooking or not using a wdh. In my question, where does the 200# go?

Some people just don't get it.. Try to help someone who doesn't get it and they question you?

[MtnGuy]

Originally Posted by OldCoot

I will pose this question to you both. WITH the wdh hooked up and assume that raised the front of the truck 1/2" from normal and it took 200 # off the front and by adding air to the bags, you got the front back down the 1/2", where would the 200# go?

The front fender measurement would not come down by just adding air to airbags.....they do little to redistribute the tongue weight. The front bumper would come down because of the overhang, but not the front fender.

With the WDH hooked up, raising the rear of the truck with air bags would actually take more weight off of the front axle, since you are relieving some of the tension on the spring bars.

Think of it this way: I think we all agree that tilting the head assembly back more increases more weight to the front axle of the TV. By adding air to the air bags, you are now tilting the WDH head assembly further forward (as the back end of the truck rises).

[locogk]

i have the husky w/d with the bars 2013 ram 1500 5.7 with 3:92 gears and air lift bags camper is 35 ft long 7400 lbs and i can't ask for better. just wish it had better m.p.g. when towing

[OldCoot]

Originally Posted by MtnGuy

...The front bumper would come down because of the overhang, but not the front fender...

Defies logic!

[SuicideSaints]

At times I am amazed! Towing is basically a statics/physics question (torques and moments) it really isn't that difficult.

In a true statics scenario air bags will not truly "distribute" tongue weight to the front, air bags counter act the downward force of the tongue weight. For instance, the true weight of the front does not change, the thing that changes is how that weight behaves. By adding a weight to the back of the CG it lifts the front up, the weight of the front remians constant but now we have the rear CG weight counter-acting how that weight is behaves from a scaled sense. So by adding airbags and lifting that rear CG weight away from the ground it forces the front end back down to where the weight is back in the normal ride position.


If mtnguy is talking from a physics standpoint only, and each piece individually (the trailer, the wdh and the truck) I am inclined to agree but the problem with this type of thinking is all 3 of these cannot be analyzed individually, from a statics standpoint it has to be the summation of all three.

When you are talking about all 3 in summation then OC is the closest explanation and his thoughts are what is in line with industry standard. A WDH helps transfer trailer weight evenly across a TV, when a WDH is not enough to 'level" a vehicle and trailer then airbags are used to raise up the TV and a drop shank is used to lower the attach point to a TV in order to level..

I think what happened in this thread is mtnguy was speaking from a statics/physics standpoint and OC was speaking from a real world all three in summation behavior standpoint. If this is what was happening then both are right in their own way.

[OldCoot]

Originally Posted by SuicideSaints

... the true weight of the front does not change, the thing that changes is how that weight behaves. By adding a weight to the back of the CG it lifts the front up, the weight of the front remians constant ...

Agree the actual weight of the front end does not change, but the weight on the tires/suspension does change from adding wt to the rear end, you can see it from watching the bulge in the tires change.

[SuicideSaints]

Originally Posted by OldCoot

Agree the actual weight of the front end does not change, but the weight on the tires/suspension does change from adding wt to the rear end, you can see it from watching the bulge in the tires change.

Yes this is what I was trying to illustrate. By adding a WDH, the WDH tries to distribute the TW evenly across the TV, this is accomplished by adding torsion between a double moment arm.

I think what mtnguy was doing was talking about the statics of each individual piece then trying to relate how that isolated piece affected the other 2 without taking into account the counteraction of the other pieces.

Airbags cannot create the same torsion arm that a WDH can.

In my opinion I would go WDH first, then if the ride you want cannot be achieved with a WDH alone, then I would go bags or helper springs in addition to the WDH. This will allow for weight distribution (correctly) to the front axle and then allow you to level (front to back) the entire rig.

[Filthy Beast]

Easy to prove or disprove. If someone that contends it does distribute weight forward. Take the rig to a scale. Take a picture or get the weight ticket to show weights, then add air to the bags and get another ticket with the new numbers. I would be interested in the results just for curiosity as I do not have a tt.


The front bumper will lower because that is in front of the pivot point being the front axle. The fender measurement, if taken at the point of the axle should not change.