Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 01-17-2022, 10:32 AM   #1
Senior Member
 
rollscanardly's Avatar
 
Join Date: Nov 2016
Location: Saunderstown, RI
Posts: 778
Question on trailer weight balancing...

Last year, we took our first trip after upgrading the rear bumper, carrying 2 kayaks and a cargo basket off of the new bumper.










The goose neck adapter is adjustable in 1" increments...











On the ride to the campground, I had the ball height set where I always towed, even before the rear bumper addition. Towed just fine.


When hooking up for the return trip, I noticed that I had set the ball height 1" higher than usual, but this was after everything was hooked up.


I stood back and studied the geometry of the truck and trailer. It looked nice...even better that the old way, plus it gave me a little more bed rail height clearance. So, off we went.


All was fine. For a while.


We were going through a highway "canyon" in New Hampshire, and the rear of the trailer started swaying side-to-side. So, I slowed down. This certainly helped, but I wanted to correct this.


We pulled off and into a parking lot of a closed business. I unhooked, and lowered the ball back down 1" to the old height. More pin weight?



We made it home, no problems.


I was telling my friend about this and he told me that if I raised the ball, that would have increased the pin weight, and went on to explain the reasoning.


I'm not sure I understood his logic. It seems to me that if we look at this as a see-saw situation, by raising the front (ball height), the rear of the trailer would become even heavier. Lowering the front of the trailer would lighten the rear of the trailer.


And, based on my experience, that is how it worked out.


So, what do you think?





Rich
__________________
"rolls down one hill, can 'ardly make it up the next..."

1999 21' Wildwood WDF21RK

2006 Dodge Ram 2500, 4x4, Quad cab, 5.9L Cummins, 3.73 gears.
rollscanardly is offline   Reply With Quote
Old 01-17-2022, 11:12 AM   #2
Senior Member
 
SeaDog's Avatar
 
Join Date: Jan 2016
Location: Idaho
Posts: 11,294
By adding weight to the rear you have reduced the pin weight somewhat so compensate for that when you load the inside. You want the trailer to run level on its axles. Your friend is mistaken. As you raise the front a trailer you decrease the amount of trail between the axles and the tongue or pin which has the effect of causing the trailer to act like a castor as you reduce the height it has the opposite affect not to mention the weight transfer your thinking is correct. JMHO
__________________
Retired Navy
Jake my sidekick (yellow Lab) 10/04 - 05/20
2017 RAM 2500 CC 4X4 Cummins Diesel
2016 Flagstaff 26 FKWS
AF&AM & El Korah Shrine of Idaho
SeaDog is offline   Reply With Quote
Old 01-17-2022, 11:26 AM   #3
Senior Member
 
clarkbre's Avatar
 
Join Date: Oct 2016
Location: Snohomish, WA
Posts: 1,124
I don't think your friend or you are right about the weight changing.

The pin weight and rear weight of the trailer are just that. Once the trailer is loaded with camping goods, the weight is set and is not changed with height. Also, the 1" change is relatively minimal in the whole scheme of things.

A couple things that come to mind as to why your trailer may have handled different than before:
  • You are correct about a see-saw effect but it has to do with the added weight off the rear bumper. The axles act as a fulcrum point between the front and back. So, if the pin is 15' from the axles and the bumper carrier is 12' from the axles, for every 200lbs loaded on the back bumper, it lessens the pin weight by 160lbs. Having less pin weight and more rear weight will certainly make the trailer feel more squirrely. This would be even more amplified if it was a bumper pull.

  • The other thing to keep in mind is a level trailer puts equal weight on all 4 tires. This isn't much of a factor for a single axle trailer but with a dual axle, if the trailer is tilted nose high, the rear axle will be carrying slightly more weight than the front axle and it be a factor in it wanting to sway a little more.
__________________

2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH
clarkbre is offline   Reply With Quote
Old 01-17-2022, 11:48 AM   #4
Senior Member
 
rollscanardly's Avatar
 
Join Date: Nov 2016
Location: Saunderstown, RI
Posts: 778
Quote:
Originally Posted by SeaDog View Post
By adding weight to the rear you have reduced the pin weight somewhat so compensate for that when you load the inside. You want the trailer to run level on its axles. Your friend is mistaken. As you raise the front a trailer you decrease the amount of trail between the axles and the tongue or pin which has the effect of causing the trailer to act like a castor as you reduce the height it has the opposite affect not to mention the weight transfer your thinking is correct. JMHO

Thanks...I understand your thought process...


Quote:
Originally Posted by clarkbre View Post
I don't think your friend or you are right about the weight changing.

The pin weight and rear weight of the trailer are just that. Once the trailer is loaded with camping goods, the weight is set and is not changed with height. Also, the 1" change is relatively minimal in the whole scheme of things.

A couple things that come to mind as to why your trailer may have handled different than before:
  • You are correct about a see-saw effect but it has to do with the added weight off the rear bumper. The axles act as a fulcrum point between the front and back. So, if the pin is 15' from the axles and the bumper carrier is 12' from the axles, for every 200lbs loaded on the back bumper, it lessens the pin weight by 160lbs. Having less pin weight and more rear weight will certainly make the trailer feel more squirrely. This would be even more amplified if it was a bumper pull.
  • The other thing to keep in mind is a level trailer puts equal weight on all 4 tires. This isn't much of a factor for a single axle trailer but with a dual axle, if the trailer is tilted nose high, the rear axle will be carrying slightly more weight than the front axle and it be a factor in it wanting to sway a little more.

...but I'm confused with your explanation.



If both of our ( my friend and I) ideas are incorrect, then why do your bullet points describe what my original explanation was?


Plus, I experienced the effect of lowering the ball 1" for the remaining 150 miles home.


I appreciate the feedback, but am scratching my head...


Rich
__________________
"rolls down one hill, can 'ardly make it up the next..."

1999 21' Wildwood WDF21RK

2006 Dodge Ram 2500, 4x4, Quad cab, 5.9L Cummins, 3.73 gears.
rollscanardly is offline   Reply With Quote
Old 01-17-2022, 12:27 PM   #5
Senior Member
 
clarkbre's Avatar
 
Join Date: Oct 2016
Location: Snohomish, WA
Posts: 1,124
Quote:
Originally Posted by rollscanardly View Post
Thanks...I understand your thought process...





...but I'm confused with your explanation.



If both of our ( my friend and I) ideas are incorrect, then why do your bullet points describe what my original explanation was?


Plus, I experienced the effect of lowering the ball 1" for the remaining 150 miles home.


I appreciate the feedback, but am scratching my head...


Rich
From your original post:

"I was telling my friend about this and he told me that if I raised the ball, that would have increased the pin weight, and went on to explain the reasoning.


I'm not sure I understood his logic. It seems to me that if we look at this as a see-saw situation, by raising the front (ball height), the rear of the trailer would become even heavier. Lowering the front of the trailer would lighten the rear of the trailer."


Because you and your friend were talking about hitch height dictating if the front or rear weighed more. It doesn't.

My explanation was/is that the seesaw affect happens if you add or decrease weight on 1 end, the other will be affected in an opposite way.

My point with the pin height and forces on each axle is what Seadog was referring to. Not having the trailer level will put different forces on the front and rear axles making it handle differently. Basically causing a caster issue that will make the trailer more susceptible to sway.

If the trailer can't be totally level rolling down the road, it's better to have it slightly nose down for stability.
__________________

2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH
clarkbre is offline   Reply With Quote
Old 01-17-2022, 12:57 PM   #6
Senior Member
 
rollscanardly's Avatar
 
Join Date: Nov 2016
Location: Saunderstown, RI
Posts: 778
Quote:
Originally Posted by clarkbre View Post
From your original post:

"I was telling my friend about this and he told me that if I raised the ball, that would have increased the pin weight, and went on to explain the reasoning.


I'm not sure I understood his logic. It seems to me that if we look at this as a see-saw situation, by raising the front (ball height), the rear of the trailer would become even heavier. Lowering the front of the trailer would lighten the rear of the trailer."


Because you and your friend were talking about hitch height dictating if the front or rear weighed more. It doesn't.

My explanation was/is that the seesaw affect happens if you add or decrease weight on 1 end, the other will be affected in an opposite way.

My point with the pin height and forces on each axle is what Seadog was referring to. Not having the trailer level will put different forces on the front and rear axles making it handle differently. Basically causing a caster issue that will make the trailer more susceptible to sway.

If the trailer can't be totally level rolling down the road, it's better to have it slightly nose down for stability.

OK...that makes it clearer. Thanks.


Rich
__________________
"rolls down one hill, can 'ardly make it up the next..."

1999 21' Wildwood WDF21RK

2006 Dodge Ram 2500, 4x4, Quad cab, 5.9L Cummins, 3.73 gears.
rollscanardly is offline   Reply With Quote
Old 01-17-2022, 06:32 PM   #7
Senior Member
 
Join Date: Dec 2019
Posts: 111
Your friend is wrong raising the height reduces the pin weight.
BM Welder is offline   Reply With Quote
Old 01-17-2022, 06:57 PM   #8
D W
Senior Member
 
D W's Avatar
 
Join Date: Sep 2016
Location: ALASKA (World's Biggest Campground)
Posts: 5,103
Quote:
Originally Posted by BM Welder View Post
Your friend is wrong raising the height reduces the pin weight.
X2. The coupler & frame are the lever, and the axles are the fulcrum. Raising the lever at the coupler end will transmit force to the opposite end of the lever - It's called Archimedes' Law of the Lever.
__________________
'07 K3500 Silverado LT Crew Duramax (LBZ)
2016 Salem 27RKSS
1984 CHEV SCOTTSDALE K20 2GCGK24J0E1XXXXXX (Chevrolet Legends-Class of 2019)
"...exhaust fluid? We don't need no stinkin' exhaust fluid"
D W is offline   Reply With Quote
Old 01-17-2022, 07:22 PM   #9
Senior Member
 
Join Date: Aug 2018
Location: Cheyenne, Wyoming
Posts: 371
Quote:
Originally Posted by rollscanardly View Post
Last year, we took our first trip after upgrading the rear bumper, carrying 2 kayaks and a cargo basket off of the new bumper.










The goose neck adapter is adjustable in 1" increments...











On the ride to the campground, I had the ball height set where I always towed, even before the rear bumper addition. Towed just fine.


When hooking up for the return trip, I noticed that I had set the ball height 1" higher than usual, but this was after everything was hooked up.


I stood back and studied the geometry of the truck and trailer. It looked nice...even better that the old way, plus it gave me a little more bed rail height clearance. So, off we went.


All was fine. For a while.


We were going through a highway "canyon" in New Hampshire, and the rear of the trailer started swaying side-to-side. So, I slowed down. This certainly helped, but I wanted to correct this.


We pulled off and into a parking lot of a closed business. I unhooked, and lowered the ball back down 1" to the old height. More pin weight?



We made it home, no problems.


I was telling my friend about this and he told me that if I raised the ball, that would have increased the pin weight, and went on to explain the reasoning.


I'm not sure I understood his logic. It seems to me that if we look at this as a see-saw situation, by raising the front (ball height), the rear of the trailer would become even heavier. Lowering the front of the trailer would lighten the rear of the trailer.


And, based on my experience, that is how it worked out.


So, what do you think?





Rich
Simple visual explanation

https://www.bing.com/videos/search?q...%26FORM%3DVDRE
bzac1954 is offline   Reply With Quote
Old 01-17-2022, 07:27 PM   #10
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 5,609
Are you sure?

Quote:
Originally Posted by clarkbre View Post
  • The other thing to keep in mind is a level trailer puts equal weight on all 4 tires. This isn't much of a factor for a single axle trailer but with a dual axle, if the trailer is tilted nose high, the rear axle will be carrying slightly more weight than the front axle and it be a factor in it wanting to sway a little more.
Clark, I disagree with this statement. It is only true in one special case. I wrote about this in another thread earlier today.

The common dual-axle trailer setup uses leaf springs. On each side, the forward axle is connected to the frame by a shackle at the front. The rear axle is connected to the frame by a shackle at the rear. In the center, the two leaf springs do not connect to the frame; they connect to opposite ends of an "equalizer" bar which itself mounts on a pivot on the frame.

If, for example, you were to place more load on the front of the trailer, the front leaf spring ends would push upward harder. That would cause the front end of the equalizer bar to go up (taking load off the front axle) and the back end of the equalizer bar to go down (putting load on the rear axle). The result is that both axles carry the same weight.

The exception to this is some lightweight dual-axle trailers that use Torflex torsion suspension instead of leaf springs. The two axles are completely independent and trailer leveling and load distribution can cause the axles to assume different loads.
Attached Thumbnails
Click image for larger version

Name:	equalizer.jpg
Views:	25
Size:	44.7 KB
ID:	267916  
__________________
Larry

Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is offline   Reply With Quote
Old 01-17-2022, 08:00 PM   #11
Senior Member
 
dsjohns71's Avatar
 
Join Date: Feb 2015
Posts: 282
Quote:
Originally Posted by Larry-NC View Post
Clark, I disagree with this statement. It is only true in one special case. I wrote about this in another thread earlier today.



The common dual-axle trailer setup uses leaf springs. On each side, the forward axle is connected to the frame by a shackle at the front. The rear axle is connected to the frame by a shackle at the rear. In the center, the two leaf springs do not connect to the frame; they connect to opposite ends of an "equalizer" bar which itself mounts on a pivot on the frame.



If, for example, you were to place more load on the front of the trailer, the front leaf spring ends would push upward harder. That would cause the front end of the equalizer bar to go up (taking load off the front axle) and the back end of the equalizer bar to go down (putting load on the rear axle). The result is that both axles carry the same weight.



The exception to this is some lightweight dual-axle trailers that use Torflex torsion suspension instead of leaf springs. The two axles are completely independent and trailer leveling and load distribution can cause the axles to assume different loads.


Lol, I was waiting on you, Larry, to comment on this as I read your other post earlier today. I have to completely agree with you on this.. great explanation!
dsjohns71 is online now   Reply With Quote
Old 01-18-2022, 11:02 AM   #12
Senior Member
 
rollscanardly's Avatar
 
Join Date: Nov 2016
Location: Saunderstown, RI
Posts: 778
My trailer only has shackles on the equalizer. The far ends of the leaf spring eyes attach directly to the hangers.

Could/ should shackles be added there? I'm guessing NO.

Rich
__________________
"rolls down one hill, can 'ardly make it up the next..."

1999 21' Wildwood WDF21RK

2006 Dodge Ram 2500, 4x4, Quad cab, 5.9L Cummins, 3.73 gears.
rollscanardly is offline   Reply With Quote
Old 01-18-2022, 11:13 AM   #13
Senior Member
 
Chuck_S's Avatar
 
Join Date: Aug 2018
Location: Richmond VA
Posts: 2,834
The weight on the ball does not change regardless of the height of the coupler. 'Cuz physics. (If this was all that was necessary the WDH manufacturers would be out of business.)

Weight at the back of the trailer -- like those kayaks -- reduces weight on the ball. 'Cuz physics. (Call it the teeter totter effect.}

Weight at the back end of the trailer -- consider the trailer as a pendulum -- increases the potential of fishtailing. 'Cuz physics. (See the linked video.)

-- Chuck
__________________
2006 Roo 23SS behind a 2017 Ford Expedition
Chuck_S is offline   Reply With Quote
Old 01-18-2022, 11:41 AM   #14
Senior Member
 
rollscanardly's Avatar
 
Join Date: Nov 2016
Location: Saunderstown, RI
Posts: 778
I realize that there is science behind these explanations, but how come I had different results just by lowering the ball?

Sheer coincidence?

Rich
rollscanardly is offline   Reply With Quote
Old 01-18-2022, 12:14 PM   #15
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 5,609
Only one end, but either end will do

Quote:
Originally Posted by rollscanardly View Post
My trailer only has shackles on the equalizer. The far ends of the leaf spring eyes attach directly to the hangers.

Could/ should shackles be added there? I'm guessing NO.

Rich
When a leaf spring deflects from its curved shape to a flatter profile, it extends in length. On a single-axle car, truck, or trailer (with no equalizer), you have to have the shackle to allow for this expansion. But if you had shackles on both ends, one would promptly collapse upward to the frame as soon as you hit a bump or braked hard. The worst situation would be it were the front shackle on one side and rear shackle on the other. The axle would be canted and tire damage would occur. You really do need the direct hanger at one end to assure a stable location.

As for a dual-axle setup with equalizers, it seems that some are built with shackles at the outer ends (the image I found) and some are built with shackles at the equalizer. I guess either works, but intuitively it seems that putting the shackles at the equalizer is better since it guarantees an absolute fore-aft location for the axle. With shackles at the extreme ends and a diagonally-unbalanced load (e.g., heavy at front-left and rear-right), the axles would be slightly canted with respect to each other.
__________________
Larry

Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is offline   Reply With Quote
Old 01-18-2022, 01:58 PM   #16
Senior Member
 
clarkbre's Avatar
 
Join Date: Oct 2016
Location: Snohomish, WA
Posts: 1,124
Quote:
Originally Posted by Larry-NC View Post
Clark, I disagree with this statement. It is only true in one special case. I wrote about this in another thread earlier today.

The common dual-axle trailer setup uses leaf springs. On each side, the forward axle is connected to the frame by a shackle at the front. The rear axle is connected to the frame by a shackle at the rear. In the center, the two leaf springs do not connect to the frame; they connect to opposite ends of an "equalizer" bar which itself mounts on a pivot on the frame.

If, for example, you were to place more load on the front of the trailer, the front leaf spring ends would push upward harder. That would cause the front end of the equalizer bar to go up (taking load off the front axle) and the back end of the equalizer bar to go down (putting load on the rear axle). The result is that both axles carry the same weight.

The exception to this is some lightweight dual-axle trailers that use Torflex torsion suspension instead of leaf springs. The two axles are completely independent and trailer leveling and load distribution can cause the axles to assume different loads.
This is a good explanation and I understand how the equalizers work to help smooth the ride. What you're explaining does make some sense. Has your explanation been tested true on a scale weighing the forces on the front and rear axles? I will admit that my theory hasn't been proven on a scale.

For conversation sake, what happens if the trailer is backed up on an incline and the rear axle is pushed up much higher (let's say 6" or so) than the front. A steep enough incline could lift the front tire off the ground. With the rear tire still touching and the front in the air, do the tires and axles carry the same weight?

__________________

2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH
clarkbre is offline   Reply With Quote
Old 01-18-2022, 04:00 PM   #17
Senior Member
 
Join Date: Jan 2018
Location: Raleigh, NC
Posts: 5,609
Obviously...

Quote:
Originally Posted by clarkbre View Post
For conversation sake, what happens if the trailer is backed up on an incline and the rear axle is pushed up much higher (let's say 6" or so) than the front. A steep enough incline could lift the front tire off the ground. With the rear tire still touching and the front in the air, do the tires and axles carry the same weight?
Obviously, once the equalizer bar has rotated to its point of maximum travel, it cannot equalize any further weight difference.

A consequence of the extreme limit is that you have to jack up one axle really high to get the other axle off the ground. It keeps dropping to try to touch the ground and carry some load until the bar hits its limit.

Also why the drive-on ramps (like you illustrated) have to be so tall. I do recall reading several posts where the writers stated that the ramps didn't work--weren't high enough to get the other wheel off the ground.
__________________
Larry

Sticks and Bricks: Raleigh, NC
2008 Cherokee 38P: at Ivor, VA permanently
Larry-NC is offline   Reply With Quote
Old 01-18-2022, 04:42 PM   #18
Senior Member
 
Join Date: Jun 2015
Location: Albuquerque
Posts: 1,072
Interested.
__________________
2009 Roo 21ss + 2007 Superduty 6.0
mnoland30 is offline   Reply With Quote
Old 01-19-2022, 12:43 PM   #19
Junior Member
 
Join Date: Nov 2016
Posts: 8
Great explanation
Dan46 is offline   Reply With Quote
Reply

Tags
question, trailer, weight

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 10:06 PM.