Calculating how an extension de-rates your receiver.

Reddog1 wrote:
Show us the math.

Wayne

https://en.wikipedia.org/wiki/Conjugate_beam_method :B

I'm a mechanical engineer, a tinkerer, a fabricator, and a farm boy, so I know exactly where you're headed...

Maybe in an EXTREME case, you could end up with over 5000lbs...

Just off the top of my head, I'm estimating it would take a tongue weight of around 2000lbs on the extension with no weight distribution to achieve that.

The truck would be undriveable with so little weight on the front wheels. I'd surely notice right away when I couldn't turn.

The joke's on you though: Even with 5000lbs on the rear axle, I'd still be under the truck's RAWR of 9350, and well under the tire limits of >10,000lbs.

Kayteg1 wrote:

Reddog1 wrote:
Show us the math.

Wayne

https://en.wikipedia.org/wiki/Conjugate_beam_method :B

Your response suggest you do not know how calculate the weight on the rear axle with an extension. I am disappointed, I thought knew what you were posting about.

Wayne

Reddog1 - I'll have a go at the math:

The tongue weight transferred to the rear axle of the tow vehicle with an extension?

Ans: All of it. ?

That was long time ago, but from my memory it was 5th grade physics how the lever works.
I know the "hands on experience" guys don't remember much of the school, so let me make quick sample.
Mine F350 is long wheel base, but my guesstimate for long bed, short cab F250/350 the wheelbase is about 9', while the standard hitch come with the ball 5' behind rear axle.
So simple sample with 4' extension will make the trailer ball 9' behind rear axle, what in this sample will equal to the distance from rear axle to front axle.
So having 1:1:1 lever the tongue weight will take equal weight off front axle, meaning the rear axle will carry both - the tongue and cantilever weight.
The 700lb tongue weight will add 1400 lb to the rear axle.
Add that close to 100% of camper weight will go on the rear axle, makes 3400lb.
Add truck own rear axle weight (around 3000lb ?), so what is the total?

Kayteg1 wrote:
... Add truck own rear axle weight (around 3000lb ?), so what is the total? ...

I really appreciate your response. No need, that I am aware of, to be coy. Being clear certainly helps for credibility. To answer a question with a question is not very clear to me.

Using the info you provided, what effect does a Weight Distribution hitch have?

I ask these questions because I am interested in factual data as to how extensions and trailers can impact our camping experience.

Wayne

EDIT: My wheelbase is 160 inches. My TC is 4200 pounds. My truck is about 7,200 pounds.

A weight distribution hitch would be akin to an adult lifting up on the right end of the teeter-totter in the picture above.

Oh, and Kayteg1's math works out to 6400lbs. My RAWR is 9350lbs. I could load another modest hardside TC on top of the one I already have and still not overload the axle.

My extension is only 14". Not 4'. So 700lbs would only add about 1000lbs to the rear axle. I wouldn't even need weight distribution at that point.

This is an awesome thought exercise guys. Thanks!

All this mental masturbation, while entertaining, does not answer the OP’s question. Find your answer
here based on the specifics of your loads, wheelbase, etc.
Curt rates that tube at 5,000 lbs.tow capacity and a tongue weight capacity of 500 lbs.
Hope this helps.

Reddog1 wrote:

Kayteg1 wrote:
... Add truck own rear axle weight (around 3000lb ?), so what is the total? ...

I really appreciate your response. No need, that I am aware of, to be coy. Being clear certainly helps for credibility. To answer a question with a question is not very clear to me.

Using the info you provided, what effect does a Weight Distribution hitch have?

I ask these questions because I am interested in factual data as to how extensions and trailers can impact our camping experience.

Wayne

EDIT: My wheelbase is 160 inches. My TC is 4200 pounds. My truck is about 7,200 pounds.

I did measure my wheel base at 13' (just with tape) so sounds like we have similar duallies although mine is over 9000 lb.
With duallies usually you don't have to worry about rear axle load, but since I put my camper with some distance behind the cabin, I am planning to stop at the scales at some point.
Weighting is highly advisable when you plan to tow.
Weight distribution is compensating for cantilever effect, but all comes with limits and putting 700 lb tension springs on long hitch extension sure brings some reliability concerns.
mkirsch got the point, so hopefully more will understand that strong extension is just the beginning of the questions you suppose to have.

billtex wrote:
All this mental masturbation, while entertaining, does not answer the OP’s question. Find your answer
here based on the specifics of your loads, wheelbase, etc.
Curt rates that tube at 5,000 lbs.tow capacity and a tongue weight capacity of 500 lbs.
Hope this helps.

billtex,

That link does NOT calculate or show how much the receiver is derated. It simply tells me how much weight is where on the truck.

Where do you get your information on how much the tube is rated for?