hitch weights

[boatms03]

I know im going to get a lot of opinions, but please try to keep the answers scientific as possible.
I am trying to compare the hitch weight of a fifth wheel trailer to the tongue weight of a bumper pull trailer. lets say the bumper pull has a tongue weight of 1200lbs and the fifth wheel has a hitch weight of 2800lbs. with the 5er the weight is pretty much over the rear axle. the bumper pull is approx 4' behind the axle (on a short bed truck). the bumper pull acts like a lever and is actually putting more force on the springs of the truck than an equal weight 5er would.

[Rvpapa]

5th total pin weight is on the rear axle. Small amount to front also depending on hitch placement.

TT total hitch weight is on the rear axle PLUS the amount lifted from the front axle.

Same reason that it is easy to overload trailer tires when hanging heavy items
on the rear.
Art.

[RCWannabe]

boatms03 wrote:
a few friends were having the discussion of whose truck is better! lol one guy said his is because his truck will not sag when his 5er is hooked up, but says the other guys truck is weak cause when he hooks up his bumper pull it sags. both have different "brand" trucks. both 3/4 ton diesel trucks. lol I am just trying to compare the two on a level playing field.. the bumper pulls tongue weight is unknown, the 5er is in the 2000 lbs range. and no im NOT getting into a truck discussion. they all have their good and bad points, and everyone has their own preference. lol like I said I just want some ammunition for the next time we are sitting around having a few cold ones and the discussion comes up.

Lol thats funny! There is no winner to that debate, I just say the one you own is the best for you. That is usually why you buy it, in my case it was the right price, had the right features and was on the lot when I walked in to the dealer.

[boatms03]

RCWannabe wrote:
I think the center point on a 5er hitch is actually a few inches in front of the rear axle and this spreads the weight out more evenly, which may change the relationship if you are trying to directly compare TT to 5er effects on the TV. I am curious what is it you are trying to figure out, there must be something more behind the question or is it just curiosity and physics?

I am not sure if it in front or behind the axle a few inches. I know the goose neck hitches in our work trucks are just behind the axle.

[boatms03]

a few friends were having the discussion of whose truck is better! lol one guy said his is because his truck will not sag when his 5er is hooked up, but says the other guys truck is weak cause when he hooks up his bumper pull it sags. both have different "brand" trucks. both 3/4 ton diesel trucks. lol I am just trying to compare the two on a level playing field.. the bumper pulls tongue weight is unknown, the 5er is in the 2000 lbs range. and no im NOT getting into a truck discussion. they all have their good and bad points, and everyone has their own preference. lol like I said I just want some ammunition for the next time we are sitting around having a few cold ones and the discussion comes up.

[RCWannabe]

I think the center point on a 5er hitch is actually a few inches in front of the rear axle and this spreads the weight out more evenly, which may change the relationship if you are trying to directly compare TT to 5er effects on the TV. I am curious what is it you are trying to figure out, there must be something more behind the question or is it just curiosity and physics?

[mena661]

BFL13 wrote:

Assuming it works the same on the back as at the front, then where:

W = weight of added accessory
A= distance accessory is from the rear axle
WB= vehicle wheelbase

Then Actual Weight added to rear axle is (W x(A + WB))/WB

So 1500lbs four feet back from rear axle with a 12 ft wheelbase is really 2000lbs on the rear axle

:E Ok, who put the pod under BFL's bed last night?

[TurnThePage]

boatms03 wrote:
billyw all i want to know is how to calculate the force exerted on the rear axle with a bumper pull. And I do pull my TH without WD hitch on occasion. I hjave no idea what my tongue weight is, I plan on finding out when I get my TH home from the deerlease.

Sorry, wasn't trying to be snarky. Maybe I'm suffering from the northern states no-camping Winter blues. 🙂

Looks like BFLs answer is a good way to get in the ballpark.

[boatms03]

and thanks BFL13 for answering my question. sometimes I hate to post a question because of all the opinions that come with the answers.

[boatms03]

billyw all i want to know is how to calculate the force exerted on the rear axle with a bumper pull. And I do pull my TH without WD hitch on occasion. I hjave no idea what my tongue weight is, I plan on finding out when I get my TH home from the deerlease.

[TurnThePage]

Wouldn't the scales answer this best? There's tons of posts around here with that info. Who would tow a trailer with a 1200 lb tongue without WD?

[BFL13]

boatms03 wrote:
I understand if you use a WD hitch it changes things, Im asking is the force 4x the tongue weight because it 4' from the axle? how do you calculate what the actual force is. the 5er should be 1:1 since it sits over the axle.

Assuming it works the same on the back as at the front, then where:

W = weight of added accessory
A= distance accessory is from the rear axle
WB= vehicle wheelbase

Then Actual Weight added to rear axle is (W x(A + WB))/WB

So 1500lbs four feet back from rear axle with a 12 ft wheelbase is really 2000lbs on the rear axle

[boatms03]

I understand if you use a WD hitch it changes things, Im asking is the force 4x the tongue weight because it 4' from the axle? how do you calculate what the actual force is. the 5er should be 1:1 since it sits over the axle.

[powderman426]

What you stated is correct for a standard ball hitch. Nobody uses that. With a weight distribution hitch it depends on how tight you pull it up. I saw a guy tighten it enough to raise the back wheels enough to slide a sheet of paper under the rear tire.

[BFL13]

I think this is in the wrong forum, but anyway, you might have that part in your truck manual on mounting a snow plow in front that has the calculation you need for the same idea with a bumper pull at the back.