Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-17-2011, 03:57 PM   #1
Rivet Master
Commercial Member
 
Moonstruck's Avatar
 
1986 31' Sovereign
1975 25' Tradewind
1967 17' Caravel
Sherfield English , Hampshire
Join Date: Oct 2006
Posts: 699
Send a message via MSN to Moonstruck Send a message via Yahoo to Moonstruck
Equalizer hitch benefits

Hi from the UK!
I have a 1972 23ft Safari with a gross weight of 3600lbs
The tongue weight is 450lbs
I have a guy who wants to tow it with a 530 BMW Touring
The "Beamer" has a max hitch capacity of 220lbs
I want to know what difference an equalizer hitch would make?
What percentage advantage would be gained with the hitch?
Marc
__________________

__________________
Silvertwinkie
Hampshire, UK
Moonstruck is offline   Reply With Quote
Old 01-17-2011, 04:09 PM   #2
Rivet Master
 
TG Twinkie's Avatar
 
1974 Argosy 26
Morrill , Nebraska
Join Date: Nov 2009
Posts: 5,140
Images: 2
Blog Entries: 5
TOOOO! Much trailer for the BMW. Especially if the hitch on the car is not rated for an equalizer hitch. It should say on a label on the hitch or in the owners manual. I certainly won't do it.
__________________

__________________
Knowledge: "A gift to be shared. A treasure to receive."
TG Twinkie is offline   Reply With Quote
Old 01-17-2011, 04:19 PM   #3
Well Preserved

 
1993 21' Sovereign
Colfax , North Carolina
Join Date: Jun 2003
Posts: 20,193
Tongue weight doesn't change with a wd setup. All the wd does is move the weight through the tongue to the front of the tow vehicle.
The only way to reduce tongue weight is to make the tongue weigh less.
__________________
overlander63 is offline   Reply With Quote
Old 01-17-2011, 04:38 PM   #4
Rivet Master
 
Wingeezer's Avatar
 
2005 30' Classic
Burlington , Ontario
Join Date: Sep 2008
Posts: 2,709
Quote:
Originally Posted by overlander63 View Post
Tongue weight doesn't change with a wd setup. All the wd does is move the weight through the tongue to the front of the tow vehicle.
The only way to reduce tongue weight is to make the tongue weigh less.



Hmmmmm.

Not meaning to argue, but I always thought that the way an equalizing hitch worked was by removing a portion of the load off the hitch and throwing some up to the front axle of the TV and some back to the trailer axles and that it did this by making the trailer and tow vehicle frames more or less "one."

It seems to me I read someplace that compared to the initla load on the ball without an equalizer, with an equalizer hitch properly set up, you would have 1/3 of the hitch weight remaining on the ball, 1/3 transferred up to the TV front axle, and 1/3 thrown back to the trailer axle(s).

Wouldn't be the first time my understanding was all wet but that is what I thought.

If that is correct, wouldn't it put the tongue weight within the acceptable range in the original poster's example?

Off course there would still the the issue to address as to whether the BMW's
hitch is rated to handle a trailer with the GVW of the AS in question.

Also, the BMW's wheelbase might not be my idea of the best for a tow vehicle, but then the trailer he is considering is pretty short.

I'm sure someone more knowlegeable will correct me if I have made any incorrect statements - I certainly don't want to spread bad info, especially with an important subject like this!


Brian



Brian.
__________________
Brian & Connie Mitchell

2005 Classic 30'
Hensley Arrow / Centramatics
2008 GMC Sierra SLT 2500HD,4x4,Crew Cab, Diesel, Leer cap.
Wingeezer is offline   Reply With Quote
Old 01-17-2011, 04:59 PM   #5
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 16,499
Images: 1
Quote:
Originally Posted by Wingeezer View Post
Hmmmmm.
Wouldn't be the first time my understanding was all wet but that is what I thought.

If that is correct, wouldn't it put the tongue weight within the acceptable range in the original poster's example?

I'm sure someone more knowlegeable will correct me if I have made any incorrect statements - I certainly don't want to spread bad info, especially with an important subject like this!

Brian.
Brian.

The formula for weight distribution is easy, provide certain requirements are met.

A proper rated, properly installed, properly adjusted weight distribting hitch, by actual measurements, will transfer 2/3 of the tongue weight to the tow vehicle and 1/3 of the tongue weight back to the trailer axle/axles.

Again, if everything is correct, 1/4 of the weight that is going to the tow vehicle, will go to each wheel.

Back in the days when most of used cars for tow vehicles, the hitch would also transfer "trunk" weight as well.

When the trunks were heavily loaded, that weight could also be transfered to the front axle of the tow vehicle, as well as some of it would go back to the trailer axle/axles. How much was a function of the setup and adjustments.

Having a good load equalizing hitch setup, however, does not correct for a poor tow vehicle.

Physics still rules out.

Andy
__________________
Inland RV Center, In is offline   Reply With Quote
Old 01-17-2011, 05:08 PM   #6
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,407
Images: 5
However, application of the spring bars to "move" weight creates an incredible amount of torque or twist through the receiver into the "frame" of the TV. If the TV isn't robust enough, it'll distort the chassis and pull out/break the mounting bolts. Another thread discusses just such an occurrence. Only the beginning, me thinks!
__________________
dznf0g is online now   Reply With Quote
Old 01-17-2011, 05:17 PM   #7
3 Rivet Member
 
Bandits's Avatar
 
2008 30' Classic
Tampa , Florida
Join Date: Oct 2009
Posts: 102
Load transfer and tongue weight.

I have measured and the bumper of my truck rises as I tighten my load transfer bars. That indicates to me that I'm moving weight off the hitch. I've got a Hensley, 2008 30' Classic and a Dodge 2500 2008 diesel. I have verified on the scales that I'm moving about 400# to the front axel by weighing with the bars adjusted to where everything appears level and then pulling back onto the scales with all tension on the bars released. I'll have to go back to my paperwork to see if there was any change in the trailer axel weight.I see a corresponding transfer from the rear truck axel to the front axel. Do I understand that if properly adjusted, all tongue weight is moved to the tow vehicle and the trailer axels? Would this result in no weight on the hitch? Jerry.
__________________
Jerry, Irene & Clancy
Bandits is offline   Reply With Quote
Old 01-17-2011, 05:24 PM   #8
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,407
Images: 5
Quote:
Originally Posted by Bandits View Post
I have measured and the bumper of my truck rises as I tighten my load transfer bars. That indicates to me that I'm moving weight off the hitch. I've got a Hensley, 2008 30' Classic and a Dodge 2500 2008 diesel. I have verified on the scales that I'm moving about 400# to the front axel by weighing with the bars adjusted to where everything appears level and then pulling back onto the scales with all tension on the bars released. I'll have to go back to my paperwork to see if there was any change in the trailer axel weight.I see a corresponding transfer from the rear truck axel to the front axel. Do I understand that if properly adjusted, all tongue weight is moved to the tow vehicle and the trailer axels? Would this result in no weight on the hitch? Jerry.
No it doesn't. In a perfect world, you would move the tongue weight equally through the AS and TV chassis to have it equally distributed along that plane. Never happens in the real world due to many variables....and maybe shouldn't.

There will still be some tongue weight on ball and a very high clamping force between ball and coupler.
__________________
dznf0g is online now   Reply With Quote
Old 01-17-2011, 05:24 PM   #9
Don't forget your cat nap
 
Ag&Au's Avatar
 
Port Orchard , Washington
Join Date: May 2009
Posts: 4,464
Images: 1
Lightbulb Weight vs Force

The problem is the choice of the word weight when talking about the tongue of a trailer.

The scientific definition of weight is the mass of an object times gravitational acceleration. Gravitational acceleration can be accepted to be constant at a give location for this purpose. So tongue weight is always constant once the mass of the tongue has been determined.

However what is important here is not the weight of the tongue. What is important is the downward force being exerted by the trailer hitch cup on the ball of the trailer.

As we all know, this downward force can be changed by a number of things, including trailer loading and angle of the trailer frame in relation to level.

A weight distribution system is a system of levers that causes this force to be distributed over the length of the TV/Trailer system.

It is as if you were standing the trailer , reaching down, and lifting up on the rear of the TV. As you lift up on the rear of the tow vehicle, you will be removing some of the downward force. Since this force is pivoted around the TV rear axle (fulcrum) it will produce a downward force on the front axle. However as you are lifting, you are also increasing the force with which your feet are pressing down on the trailer. This force is what appears as increased weight on the trailer axle.

Maybe it would be clearer if they were called force distribution hitches.

Yes, I have too much time on my hands.

Regards,

Ken

Quote:
Originally Posted by Wingeezer View Post
Hmmmmm.

Not meaning to argue, but I always thought that the way an equalizing hitch worked was by removing a portion of the load off the hitch and throwing some up to the front axle of the TV and some back to the trailer axles and that it did this by making the trailer and tow vehicle frames more or less "one."

It seems to me I read someplace that compared to the initla load on the ball without an equalizer, with an equalizer hitch properly set up, you would have 1/3 of the hitch weight remaining on the ball, 1/3 transferred up to the TV front axle, and 1/3 thrown back to the trailer axle(s).

Wouldn't be the first time my understanding was all wet but that is what I thought.

If that is correct, wouldn't it put the tongue weight within the acceptable range in the original poster's example?

Off course there would still the the issue to address as to whether the BMW's
hitch is rated to handle a trailer with the GVW of the AS in question.

Also, the BMW's wheelbase might not be my idea of the best for a tow vehicle, but then the trailer he is considering is pretty short.

I'm sure someone more knowlegeable will correct me if I have made any incorrect statements - I certainly don't want to spread bad info, especially with an important subject like this!


Brian



Brian.
__________________
Ag&Au is offline   Reply With Quote
Old 01-17-2011, 06:00 PM   #10
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
first let's answer the OP needs specifically.

the 530 touring is the euro version of the 5 series station WAGON...

and it can be used for towing a 70s 23 footer, with minor tweaks.

the 220LB (100 kg) rated receiver is with ON THE BALL TOWING...

IF the receiver isn't rated for w/d gear that's it.

OTOH if the receiver has 2 ratings (which is doubtful)

as in with/without w/d, the rating WITH w/d will be higher.

IF the receiver is NOT rated for w/d of any sort,

the OP needs to buy an aftermarket replacement receiver rated 4 at least 500lbs or ~class iii in north american parlance.

the aftermarket receiver might carry that 500 lb rating WITH or withOUT w/d depending on model.

using w/d WOULD be useful since it would help to REload the bmw steering axle,

which will be LIGHTENED 150 lbs or so without w/d.

there are class iii receiver versions compatible with the OEM holes on the bimmer,

or a welding shop (visavis caNam) could fabricate the connections onto the unIbody.
__________

cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 01-17-2011, 06:05 PM   #11
Don't forget your cat nap
 
Ag&Au's Avatar
 
Port Orchard , Washington
Join Date: May 2009
Posts: 4,464
Images: 1
After rereading my previous post, I think the below quote should be changed to read:

As you lift up on the rear of the tow vehicle, you will be applying upward force that will counteract some of the downward force.


Quote:
Originally Posted by w7ts View Post

....................
As you lift up on the rear of the tow vehicle, you will be removing some of the downward force.
.................................................. ...

Regards,

Ken
__________________
Ag&Au is offline   Reply With Quote
Old 01-17-2011, 06:07 PM   #12
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,407
Images: 5
Quote:
Originally Posted by 2airishuman View Post
first let's answer the OP needs specifically.

the 530 touring is the euro version of the 5 series station WAGON...

and it can be used for towing a 70s 23 footer, with minor tweaks.

the 220LB (100 kg) rated receiver is with ON THE BALL TOWING...

IF the receiver isn't rated for w/d gear that's it.

OTOH if the receiver has 2 ratings (which is doubtful)

as in with/without w/d, the rating WITH w/d will be higher.

IF the receiver is NOT rated for w/d of any sort,

the OP needs to buy an aftermarket replacement receiver rated 4 at least 500lbs or ~class iii in north american parlance.

the aftermarket receiver might carry that 500 lb rating WITH or withOUT w/d depending on model.

using w/d WOULD be useful since it would help to REload the bmw steering axle.

their are class iii receiver versions compatible with the OEM holes on the bimmer,

or a welding shop (visavis caNam) could fabricate the connections onto the unIbody.
__________

cheers
2air'
However, if BMW doesn't have the dual rating (I assumed not) there is a reason. If BMW does not recommend a "Weight distributing" tongue weight spec. there is a reason probably having to do with the chassis/suspension construction. I would not add a different receiver to accomodate a higher distributed load without BMW's blessing. I believe ignoring this will result in eventual substantial repairs and perhaps safety issues.
__________________
dznf0g is online now   Reply With Quote
Old 01-17-2011, 06:09 PM   #13
_
 
. , .
Join Date: Dec 2004
Posts: 8,812
yes ken that's better.
________

the op appears 2b confused a bit about what w/d does (as many here are)

there is no "percentage advantage" gained and no alteration of WHAT the tongue weighs using w/d gear.

there are 100s of posts in other threads that coherently splain this,

but posts #3 and #9 get right to the pith and core.
________

along with the confusion related to the terms weight vs force,

the term 'load equalizing' should be trashed.

it's intentionally confusing and serves almost NO modern towing need or discussion.

except for the 'brand name with the Eq' term, all other use of this confusing term should be banned...

along with the folks using it.



cheers
2air'
__________________
all of the true things that i am about to tell you are shameless lies. l.b.j.

we are here on earth to fart around. don't let anybody tell you any different. k.v.
2airishuman is offline   Reply With Quote
Old 01-17-2011, 06:12 PM   #14
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 9,407
Images: 5
Ya know...after giving this some thought.....with global companies, there may be a "communication" issue here. I gather, from this forum, that trailers in Europe are not typically of the size to require weight distributing hitches. BMW of Europe may not publish specs for weight distributing hitches while BMW
USA may for the very same vehicle. If you call BMW Europe, they may not even know what the heck you are talking about. Try BMW USA for a spec.
__________________

__________________
dznf0g is online now   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hitch bolt broke - now what? adwriter73 Hitches, Couplers & Balls 51 05-26-2011 07:07 PM
Which Hitch to buy? jomondnv Hitches, Couplers & Balls 19 01-01-2011 08:22 AM
How and When to Measure Hitch Height lcurrie Hitches, Couplers & Balls 9 12-30-2010 02:59 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 08:21 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.