There has been some discussion on several other threads on this subject. It is understood that the use of a WDH causes several changes in actual measured weights of both tow vehicle and caravan. My claim is that one of these changes is a reduction of towball loading. Attached is a chart from a Haymen Reece display.
UNHITCHED WEIGHTS van wheels 1230 Kgs van towball 220 Kgs therefore the vans ATM is 1450 Kgs Tug 1690Kgs
HITCHED WEIGHTS (NO WDH) van wheels 1230 Kgs van towball is listed as zero (but not measured) vans ATM still 1450 Kgs Tug 1910Kgs
HITCHED WEIGHTS WITH WDH van wheels 1290 Kgs ditto vans ATM still 1450 Kgs Tug 1850 Kgs
The reason the towball weight is not listed for hitched conditions is
From these figures by means of simple arithmetic can be worked the following
(1) the tug has increased in weight by the full 220Kgs without the WDH , but only 160 Kgs with it fitted. Hence the ball loading can now only be 160Kgs.
(2) The van GTM has increased by 60Kgs after the WDH is fitted. By arithmetic again 1450-1290 =160Kgs the weight now on the towball.
This clearly shows that the belief that a WDH dosen't change the towball loading is wrong. It matters in cases where towball loading is limited due to factors such as factory specs of tow vehicle.
Alan
-- Edited by Brenda and Alan on Wednesday 6th of May 2020 09:03:58 PM
I noticed after posting the above thread that the weight of the WDH is missing from the weights measured. I can only assume that it was weighed with either the tug or van on the first two weighings.
Alan
Brenda and Alan said
09:58 PM May 6, 2020
Here is a link to an article from Outback travel Australia. Note the comments about WDH being used to reduce the tow ball loadings on Subaru vehicles which have very low tow ball weights. Also you may notice that the myth of 10% tow ball weight is also discussed.
B and A I'm sure that you will have noticed that posters are not going anywhere near this post. Funny that???
-- Edited by Magnarc on Saturday 9th of May 2020 01:47:35 PM
outlaw40 said
01:01 PM May 9, 2020
Probably because the second someone comments Yobarr will be on them like a rash on a hookers privates .
KFT said
01:17 PM May 9, 2020
G'day
My take on Brenda & Alan's OP is that the towball mass is not reduced at all. That mass is now distributed to the van wheels as well as the tug and that is exactly what a WDH is designed to do. Basic physics would tell you the ball mass can not "go away" or be changed it can only be distributed to somewhere else by the use of devices like WDH.
lets see if we will need some popcorn??
Frank
yobarr said
06:00 PM May 9, 2020
outlaw40 wrote:
Probably because the second someone comments Yobarr will be on them like a rash on a hookers privates .
Steve,there is no need to panic! On the very day that Alan posted this,I sent him a PM saying that I would not dignify his post by responding to it.In my email I explained exactly how a WDH works,and showed that a WDH does not,never has and never will change towball weight.I explained that there were so many holes in the post that it would take me a day to respond.A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATMalso is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change.Simple physics at work! Since I have received neither acknowledgement nor reply,I can only surmise that my detaied explanation has again helped someone understand the workings of a WDH? But I must admit that I know absolutely nothing about "a rash on a hookers privates! Cheers
Bobdown said
11:15 AM May 10, 2020
I'm no suspension expert by far, but surely a WDH is a legal and worthwhile addition to a van and tug setup.
When I purchased my current van, I measured the height of the rear of the tug, connected the van and measured again.
The back of the tug had dropped 60 mm, the van looked nose down.....tug nose up.
Put the WDH on and the back of tug went up 50 mm, van and tug looked to be sitting nice and level.
To me, the steering was how it should be, it towed really well, not overweight and no swaying.
A lot of toing and froing regards the use of them, but I'm happy with mine..........do you have one Yobarr?
Cheers Bob
yobarr said
02:16 PM May 10, 2020
Bobdown wrote:
I'm no suspension expert by far, but surely a WDH is a legal and worthwhile addition to a van and tug setup.
When I purchased my current van, I measured the height of the rear of the tug, connected the van and measured again.
The back of the tug had dropped 60 mm, the van looked nose down.....tug nose up.
Put the WDH on and the back of tug went up 50 mm, van and tug looked to be sitting nice and level.
To me, the steering was how it should be, it towed really well, not overweight and no swaying.
A lot of toing and froing regards the use of them, but I'm happy with mine..........do you have one Yobarr?
Cheers Bob
Hi Bob.....I am happy that your WDH has done what you wanted to achieve,but I do not use one,although there is an HR example in my shed.If the sole reason for using a WDH is to level the car,they may be a good thing,but unfortunately,in the vast majority of cases,the WDH is used in an effort to make a car do things for which it never was designed.The main problem faced by many caravanners is the overloading of the car's rear axle,with the WDH being seen as a "cure all",but it can create as many problems as it solves....think "oversteer". Buying the right car,or indeed,the right van,is the secret.With my car,I run at 6800kg GCM,legal on all axles,and no WDH,because I did my research before buying.There is 1350kg on the front axle,2300kg on the rear axle,and the GTM (weight on van wheels) is 3150kg.The car is thus around 16% heavier than the car,and very safe.......little chance of the "tail wagging the dog" that often occurs when the van is heavier than the car.If safety is of any concern,the weight on the wheels of the car should be at least 10% greater than the weight on the van's wheels,with some experts preferring the car to be 20% heavier. Many people have little understanding of weights,and spend thousands of dollars on a GVM upgrade without undestanding what it actually does.One popular model is often given a GVM upgrade from 3350kg to 3800kg,but the rear axle carrying capacity increases by only 50kg.....yes,a miserable 50kg,yet the upgrade costs thousands of dollars.Why would you bother? Cheers
Brenda and Alan said
04:19 PM May 13, 2020
Yobbar this quote from your post shows you have not seriously looked at my post, but just rejected it.
"A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATMalso is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change."
You have forgotton that the 34 Kgs returned to the vans wheels is only a part of the towball weight, the rest is now on the tugs axles.So if you claim that the ATM of the van has increased by 34Kgs the GCM of your rig would have increased by this amount also. Obviously this can't be. So the ATM of the van can't have increased.
Check my post again. All the weights I have used in the example come from a demo weighing by Haymen Reece themselves and is attached to the original post. I can assure you the arithmetic is correct. The weight on the tugs axles transmitted there by the weight on the towbar is 160Kgs, the increase in GTM of the van 60Kgs. the sum of these two weights is the original towball weight.
Don't bother sending me another PM unless you can discuss this issue rationaly unlike your last.
Alan
iana said
06:00 PM May 13, 2020
The Neverending Story La dee da da da
Its all just fun guys.
-- Edited by iana on Wednesday 13th of May 2020 06:01:30 PM
ATM, GTM & GCM are RATINGS folks, they NEVER change no matter what you do.
If you don't understand the terminology there is little hope of explaining anything sensibly.
Cheers,
Peter
yobarr said
07:44 PM May 13, 2020
Peter_n_Margaret wrote:
ATM, GTM & GCM are RATINGS folks, they NEVER change no matter what you do. If you don't understand the terminology there is little hope of explaining anything sensibly. Cheers, Peter
Hi Peter....I absolutely do understand the terminology,but I do always try to simplify things for those who have absolutely NO understanding of the basic physics involved in the equation.Tomorrow,when I have more time,I will again attempt to help Alan understand that towball weight NEVER changes when a WDH is tensioned.NEVER.All weight transferred is removed from the car's rear axle,(NOT the towball) with a percentage of this,usually about 70%,being transferred to the car's front axle,and the remaining 30% being transferred to the van's axle group.The reason for using the term "about" is that the weight transferred depends on several things,such as the wheelbase of the car,the TBO (distance from rear axle to hitch point) and the distance from hitchpoint to van's axle group. TOWBALL WEIGHT NEVER CHANGES when a WDH is tensioned.Period.The confusion of people like Alan doesn't really bother me,with my major concern being that the misinformation they post may cause "newbies" etc to make decisions that endanger not only themselves and other road users,but may cause any insurance claim they need to make to be denied when their insurance company determines that they were overloaded,and unsafe.But ignorance is bliss.Cheers
P.S "Towball listed as zero,but not measured",surely makes a mockery of all submitted figures?
KJB said
08:12 PM May 13, 2020
This argument is worse than the Corona Virus - it just keeps coming back ... and everyone is sick of it....
Peter_n_Margaret said
08:30 PM May 13, 2020
The thread title is clear. There is no compulsion to read.
If you are not interested then it is a simple thing to simply BUTT OUT and stop winging because that is worse.
Cheers,
Peter
yobarr said
09:06 PM May 13, 2020
KJB wrote:
This argument is worse than the Corona Virus - it just keeps coming back ... and everyone is sick of it....
Kerry....as Peter has advised,there is no compulsion to read this,or indeed any,thread.Because you have an obvious interest in this subject,you will have noted that these posts invariably are started by people who have little understanding of the physics involved,but post anyway.The reason that replies are posted by those of us who do actually understand is to try to prevent "newbies" and others from being mislead,or falsely reassured that what they are doing is indeed legal and safe.In many cases,it is not.The reason that I participate in these "discussions" is solely to correct the misinformation........perhaps misunderstandings..............often posted by people who no doubt have good intentions but little apparent comprehension of the actual physics involved.Unlike other topics,when discussing weights there is no room for opinion.....weights are either right or they are wrong.Because of the frequent conflict in these "discussions" I sometimes choose to PM members,@and by doing this I have helped several to acquire a good understanding of weights,unsuitable cars,and the real effects of a WDH.My hope is that you now understand our motives,but I will again point out that threads such as this are rarely started by those of us who do know what we're talking about.....we have nothing to prove! Cheers
yobarr said
09:00 AM May 14, 2020
Brenda and Alan wrote:
Yobbar this quote from your post shows you have not seriously looked at my post, but just rejected it.
"A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATMalso is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change."
You have forgotton that the 34 Kgs returned to the vans wheels is only a part of the towball weight, the rest is now on the tugs axles.So if you claim that the ATM of the van has increased by 34Kgs the GCM of your rig would have increased by this amount also. Obviously this can't be. So the ATM of the van can't have increased.
Check my post again. All the weights I have used in the example come from a demo weighing by Haymen Reece themselves and is attached to the original post. I can assure you the arithmetic is correct. The weight on the tugs axles transmitted there by the weight on the towbar is 160Kgs, the increase in GTM of the van 60Kgs. the sum of these two weights is the original towball weight.
Don't bother sending me another PM unless you can discuss this issue rationaly unlike your last.
Alan
Alan....this post again illustrates that you are well and truly lost in the WDH wilderness.There are so many holes in your "logic" that it will take me hours to explain,but in the 7th line of this post you again say "..the 34kg returned to the van's wheels is only a part of the towball weight...". It seems that you still do not understand that that 34kg was NEVER part of the towball weight.The 34kg was transferred from the car's rear axle along with the 66kg that was returned to the car"s front axle.Later today I will try to find a couple of hours to PM you a detailed analysis of your post,pointing out the mistakes/misunderstandings,but in the meantime you may like to ponder why your original,post states that towball weight is "...listed as zero. (but not measured)".This certainly is convenient for your arguement,but is a nonsense.Cheers.
Iva Biggen said
10:30 AM May 14, 2020
yobarr wrote:
Brenda and Alan wrote:
Yobbar this quote from your post shows you have not seriously looked at my post, but just rejected it.
"A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATMalso is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change."
You have forgotton that the 34 Kgs returned to the vans wheels is only a part of the towball weight, the rest is now on the tugs axles.So if you claim that the ATM of the van has increased by 34Kgs the GCM of your rig would have increased by this amount also. Obviously this can't be. So the ATM of the van can't have increased.
Check my post again. All the weights I have used in the example come from a demo weighing by Haymen Reece themselves and is attached to the original post. I can assure you the arithmetic is correct. The weight on the tugs axles transmitted there by the weight on the towbar is 160Kgs, the increase in GTM of the van 60Kgs. the sum of these two weights is the original towball weight.
Don't bother sending me another PM unless you can discuss this issue rationaly unlike your last.
Alan
Alan....this post again illustrates that you are well and truly lost in the WDH wilderness.There are so many holes in your "logic" that it will take me hours to explain,but in the 7th line of this post you again say "..the 34kg returned to the van's wheels is only a part of the towball weight...". It seems that you still do not understand that that 34kg was NEVER part of the towball weight.The 34kg was transferred from the car's rear axle along with the 66kg that was returned to the car"s front axle.Later today I will try to find a couple of hours to PM you a detailed analysis of your post,pointing out the mistakes/misunderstandings,but in the meantime you may like to ponder why your original,post states that towball weight is "...listed as zero. (but not measured)".This certainly is convenient for your arguement,but is a nonsense.Cheers.
So far this year I have tried to ignore your posts Yobar but you are really one very rude, self opinionated dude.
You tell us all on here your know more than vehicle manufacturers, approved secondary vehicle manufacturers and now you know more than a major WDH manufacturer.
I have asked this of you many times before, SHOW US YOUR CREDENTIALS which make you correct and the others wrong.
Brenda and Allen,
He has done exactly that and ignored what you said, and it is funny because that is the very action that he accuses all others of doing when they dont agree with his drivel.
I cannot for the life of me see why he is still permitted to contribute on here. I am now thinking it can only be for the entertainment value.
There is a link to video that explains fully with weighbridge proof of the effects of a WDH. It is on UTube for any that may be interested. If I find it today I will provide the link.
The problem that anyone has when they mention anything to do with WDH or approved secondary vehicle modification is that you, Yobar, need to justify to all on here, your decision by choosing not to have these mods.
Cheers
Ivan
yobarr said
01:18 PM May 14, 2020
This is a list of the more common towing misconceptions.Of particular relevance to this thread is the explanation,in the third topic,that a WDH does NOT change towball weight.Simple physics at work.Some members might also like to take particular note of the sad truth revealed in the first topic? Cheers..
-- Edited by iana on Wednesday 13th of May 2020 06:01:30 PM
Here are Ian, I will share with ya mate.
iana said
04:41 PM May 14, 2020
Thanks Doug, I feel a bit crapped off at the moment. Best I say no more.
Dougwe said
06:51 PM May 14, 2020
RUOK Ian?
Amigo1 said
11:50 PM May 14, 2020
yobarr wrote:
This is a list of the more common towing misconceptions.Of particular relevance to this thread is the explanation,in the third topic,that a WDH does NOT change towball weight.Simple physics at work.Some members might also like to take particular note of the sad truth revealed in the first topic? Cheers..
I am have no credentials in this field but as a novice and for the sake of towing safety some "facts" on this subject do interest me.
So, as only a well credentialled Googler and after a quick search, I have discovered that yobarr's list of 4 items is simply part of a list 8 items contained in an article entitled "Top eight towing myths busted" and published on the reputable Australian Cars Guide website at this address: https://www.carsguide.com.au/tradies/advice/top-eight-towing-myths-busted-73044 . Yes I know that this may be just one person's opinion, but that person is Mark Oastler, who is a long time, reputable, Australian motor sports commentator. I would not think he would publish such an article without some technical advice to back him up, whatever/whoever that might be, nor would Cars Guide's duty of care/safety allow its publication without any such basis?
Again, a specialist WDH website of Alko, regarded as a "holy grail" of caravan engineering and accessories very clearly says on this link, http://www.withoutahitch.com.au/caravan/set-weight-distribution-hitch/# , that:
"When a weight distribution hitch is tensioned, the back of the vehicle and the front of the caravan are raised, with a portion of the load shifting to the front of the vehicle. It might then seem logical to assume that the ball weight has been reduced, but this is not the case. Without a weight distribution hitch fitted, the towbar assembly would just have a simple downward force imposed on it by the caravans coupling. But when a weight distribution hitch is fitted, it requires for that same towbar assembly to twist forward. The towbar is therefore not dealing with less weight when a weight distribution hitch has been attached and tensioned."
And finally, this link to the specialist caravan website, GoRv, https://www.gorv.com.au/weight-distribution-hitch/ , written by a well known guru and author in the caravan towing field, Collyn Rivers, seems to also debunk the so called myth about WDH and towball weight when among other things Collyn mentions:
"Called a weight distributing hitch, it levered up the rear of that tow vehicle, and levered down the front of that vehicle, in effect lessening some of that tow ball weight on the tow vehicles rear tyres to restore that on its front tyres. A smaller amount was also transferred to the caravans tyres." There are other websites that make a similar comment. Perhaps such comments support the Cars Guide myth buster as well as yobarr's contention that it is the tow ball's weight on the rear axle that is being transferred, not the weight bearing down onto the tow ball itself? This is just my layman's conclusion from after reading the above two references.
So before we all "shoot the messenger" (yobarr?), argue ourselves to death and as well as make suggestions about banning a member who refuses to roll over on a subject that he is clearly passionate about, perhaps all posters can provide their own link(s) to any reputable source which backs up any data and comments they make on this technical subject. Then we can all read the links and make our own objective conclusions?
Cheers,
Phillip
PS: When and if there is a 2021 Sydney Caravan Show, I shall ask the Hayman-Reece WDH specialisit conducting the demo there what facts and documentation he can put me nto that might debunk or back-up the so called myth!
-- Edited by Amigo1 on Thursday 14th of May 2020 11:52:22 PM
-- Edited by Amigo1 on Friday 15th of May 2020 10:44:57 AM
-- Edited by Amigo1 on Friday 15th of May 2020 10:46:41 AM
I have refaimed from commenting on this thread for hope it would remain amicable.
On another forum as soon as one appears the anti WDH brigade hops on to the thread and makes stupid comments about them as being band aids etc etc, I have even asked some of these people to provide us with their personal experiance in the use of a WDH, none has been forthcoming.
So would like to put the to you the anti WDH posters, your negative comments serve no purpose in assisting those who ask questions about their use or suitability, likewise my responses are about my personal experiance and research I have made, I do not expect every combination to have a WDH, however one will never know if they do or do not need to use one unless their coupling and ball heights are not setup correctly.
Initally you dont need to know ball weights, axle weights or towball overhang to assess, if you require the services of a WDH.
A good starting point is to read your owners manuals towing section and if the manufacture has a towing guide consult it for their recomendations, some demand the use of a WDH others forbid their use with others offer no reccomendation one way or the other, at the end of the day it's up to you if you need one or not.
One responder suggested following the advice of the person he named, I have found when asking that person specific questions about the use and application of weight distibution hitches, his responses were all based on theroitical data, when pressed about praticial experiance he retreated from the conservation, just like he did when he was a supporter of SAE's J2807 document where he and others took a single testing control and extrapoulated that to be a reccomundation applied to all WDH's retrospectivly.
Now going back to the OP whislt I am a supporter of the use of weight distribution hitches, there is a problem with these presentations as they are primarlily designed to sell their products, they mislead punters because they are in a controlled enviroment and are devoid of reality.
Lets go to reality the punter buys a vehicle he perceives to be suitable for towing the van of his choice, generally he has no idea about the weights of his vehicle other than it can tow 3500kg because thats what the advertising and salesman said it could, as for the van he can the little compliance plate which gives him the ATM, GTM and Tare(the tare is a fictious number). The salesman at van dealer if he's any good he will up sell you a few items which you may or may not need, one of them could be a WDH.
You have got your new tow vehicle and van home where you load them up with all sundry of items, then you hook them together, oh! crikey, the arse of the tug is down low and nose of the van is there to. At this point in time you do not know you axle weights nor the GVM or GCM along with your ball weight and actual GTM and ATM, or you may be lucky enough to have it all look pretty good.
If you have the former you may proceed to adjust where things are loaded in both units to make it look pretty good, you may decide to use that WDH you brought, one would hope you follow the instructions as supplied with it. Now everthing look real good we have an approximate idea of our ball weight because that salesman sold us one of the towball scales, now is the time we should go to the weighbridge and weigh everything, does that happen maybe maybe not.
This is where reality and fiction differ to get to the weighbridge if are required to use a WDH you need to set it up using the measurement system and then get to the weighbridge to confirm your weights and make any neccessary adjustments that are needed, unless you have a weighbridge in your backyard.
-- Edited by Gundog on Friday 15th of May 2020 10:44:47 AM
yobarr said
11:35 AM May 15, 2020
Gundog wrote:
I have refaimed from commenting on this thread for hope it would remain amicable.
On another forum as soon as one appears the anti WDH brigade hops on to the thread and makes stupid comments about them as being band aids etc etc, I have even asked some of these people to provide us with their personal experiance in the use of a WDH, none has been forthcoming.
So would like to put the to you the anti WDH posters, your negative comments serve no purpose in assisting those who ask questions about their use or suitability, likewise my responses are about my personal experiance and research I have made, I do not expect every combination to have a WDH, however one will never know if they do or do not need to use one unless their coupling and ball heights are not setup correctly.
Initally you dont need to know ball weights, axle weights or towball overhang to assess, if you require the services of a WDH.
A good starting point is to read your owners manuals towing section and if the manufacture has a towing guide consult it for their recomendations, some demand the use of a WDH others forbid their use with others offer no reccomendation one way or the other, at the end of the day it's up to you if you need one or not.
One responder suggested following the advice of the person he named, I have found when asking that person specific questions about the use and application of weight distibution hitches, his responses were all based on theroitical data, when pressed about praticial experiance he retreated from the conservation, just like he did when he was a supporter of SAE's J2807 document where he and others took a single testing control and extrapoulated that to be a reccomundation applied to all WDH's retrospectivly.
Now going back to the OP whislt I am a supporter of the use of weight distribution hitches, there is a problem with these presentations as they are primarlily designed to sell their products, they mislead punters because they are in a controlled enviroment and are devoid of reality.
Lets go to reality the punter buys a vehicle he perceives to be suitable for towing the van of his choice, generally he has no idea about the weights of his vehicle other than it can tow 3500kg because thats what the advertising and salesman said it could, as for the van he can the little compliance plate which gives him the ATM, GTM and Tare(the tare is a fictious number). The salesman at van dealer if he's any good he will up sell you a few items which you may or may not need, one of them could be a WDH.
You have got your new tow vehicle and van home where you load them up with all sundry of items, then you hook them together, oh! crikey, the arse of the tug is down low and nose of the van is there to. At this point in time you do not know you axle weights nor the GVM or GCM along with your ball weight and actual GTM and ATM, or you may be lucky enough to have it all look pretty good.
If you have the former you may proceed to adjust where things are loaded in both units to make it look pretty good, you may decide to use that WDH you brought, one would hope you follow the instructions as supplied with it. Now everthing look real good we have an approximate idea of our ball weight because that salesman sold us one of the towball scales, now is the time we should go to the weighbridge and weigh everything, does that happen maybe maybe not.
This is where reality and fiction differ to get to the weighbridge if are required to use a WDH you need to set it up using the measurement system and then get to the weighbridge to confirm your weights and make any neccessary adjustments that are needed, unless you have a weighbridge in your backyard. -- Edited by Gundog on Friday 15th of May 2020 10:44:47 AM
Hi Graham...it is not often that I agree with your representations,but you are to be commended you for this GREAT post.As you suggest,the ONLY way to get your weights right is to visit a weighbridge and conduct a series of tests.This is how I produced the figures I have already posted on this forum, showing that a WDH has NO effect on towball weight. Cheers.
Gundog said
12:45 PM May 15, 2020
yobarr wrote:
Hi Graham...it is not often that I agree with your representations,but you are to be commended you for this GREAT post.As you suggest,the ONLY way to get your weights right is to visit a weighbridge and conduct a series of tests.This is how I produced the figures I have already posted on this forum, showing that a WDH has NO effect on towball weight. Cheers.
Yes you are correct a WDH has no effect on towball weight.
Likewise towball weight becomes irrelevent when tow vehicle and caravan are connected, all that matters thereafter are the GCM, GTM Axle Weights and the towing capacity of the the tow vehicle.
Radar said
09:44 PM May 15, 2020
Gundog wrote:
I have refaimed from commenting on this thread for hope it would remain amicable.
On another forum as soon as one appears the anti WDH brigade hops on to the thread and makes stupid comments about them as being band aids etc etc, I have even asked some of these people to provide us with their personal experiance in the use of a WDH, none has been forthcoming.
So would like to put the to you the anti WDH posters, your negative comments serve no purpose in assisting those who ask questions about their use or suitability, likewise my responses are about my personal experiance and research I have made, I do not expect every combination to have a WDH, however one will never know if they do or do not need to use one unless their coupling and ball heights are not setup.
________________________________
So anti wdh comments not welcome because why, it may upset you.
Maybe wdh are not what people really need.
I stopped using them after spending money on the cars suspension, to tow better, loading the caravan correctly and not exceeding the GVM or getting close to the GCM of our car.
Negitives are extra weight of the wdh, noticing understeer on tow vehicle with caravan attached.
iana said
06:36 AM May 16, 2020
No body has mentioned "Center of Gravity". If we were to take a single axle van with an ATM of 2500kg, and the center of gravity (which I will call C of G) was at a point vertically above the axle, the ball weight would be zero.
With the draw bar (hitch point) set at the horizontal, which I will call zero degrees, a set of scales at the hitch would read O kg. If some of the weight in the van was moved forward, the scales would begin to read, as the C of G moves forward. Now the hitch is sharing some of the load. By moving more of the internal cargo load forward, so that the ball weight now reads 250 kg, the C of G will have moved forward, by how much would depend on the van, and I would have no idea where the C of G point is.
We can now say the Ball weight is 250 kg with the hitch point at 0 degrees to the horizontal.
If you hitch the van up, and the weight of the draw bar causes the back of the vehicle to drop, the draw bar is no longer at 0 degrees, it is now maybe -2 degrees, the van has rotated about its axis (in this case the axles), and the C of G has moved forward. The hitch will now be sharing more of the van load. The ball weight has increased, it is now maybe 260 kg.
If you now use some method to raise the tow ball using heavier rear springs, air bags, or WDH, so that the hitch is now back to zero degrees to the horizontal, the load sharing of the hitch will be back to 250 kg.
Gundog said
09:59 AM May 16, 2020
Radar wrote:
________________________________
So anti wdh comments not welcome because why, it may upset you. Upset me no, how would you feel if your advice lead to someone misfortune.
Maybe wdh are not what people really need. Depending not all vehicles need a WDH but some do, would you advise them not to use one when its a requirement to use one by the vehicle manufacturer. One wonders if I choose not to use one and had an accident wether the insurance company might void my insurance for failing to use the required equipment to tow a trailer in excess of 1800kg
I stopped using them after spending money on the cars suspension, to tow better, loading the caravan correctly and not exceeding the GVM or getting close to the GCM of our car. Great I'm glad it works for you.
Negitives are extra weight of the wdh, noticing understeer on tow vehicle with caravan attached. I see no negatives the few Kg's difference between a WDH and Heavy Duty Hitch, unless you are you are that close to the GVM. There has never been any understeer with my setup because the WDH returns the lost weight from the front axle from the rear axle.
Fortunatly for me I have about 150kg of load available from my GCM at the last weighing.
There has been some discussion on several other threads on this subject. It is understood that the use of a WDH causes several changes in actual measured weights of both tow vehicle and caravan. My claim is that one of these changes is a reduction of towball loading. Attached is a chart from a Haymen Reece display.
UNHITCHED WEIGHTS van wheels 1230 Kgs van towball 220 Kgs therefore the vans ATM is 1450 Kgs Tug 1690Kgs
HITCHED WEIGHTS (NO WDH) van wheels 1230 Kgs van towball is listed as zero (but not measured) vans ATM still 1450 Kgs Tug 1910Kgs
HITCHED WEIGHTS WITH WDH van wheels 1290 Kgs ditto vans ATM still 1450 Kgs Tug 1850 Kgs
The reason the towball weight is not listed for hitched conditions is
From these figures by means of simple arithmetic can be worked the following
(1) the tug has increased in weight by the full 220Kgs without the WDH , but only 160 Kgs with it fitted. Hence the ball loading can now only be 160Kgs.
(2) The van GTM has increased by 60Kgs after the WDH is fitted. By arithmetic again 1450-1290 =160Kgs the weight now on the towball.
This clearly shows that the belief that a WDH dosen't change the towball loading is wrong. It matters in cases where towball loading is limited due to factors such as factory specs of tow vehicle.
Alan
-- Edited by Brenda and Alan on Wednesday 6th of May 2020 09:03:58 PM
I noticed after posting the above thread that the weight of the WDH is missing from the weights measured. I can only assume that it was weighed with either the tug or van on the first two weighings.
Alan
Here is a link to an article from Outback travel Australia. Note the comments about WDH being used to reduce the tow ball loadings on Subaru vehicles which have very low tow ball weights. Also you may notice that the myth of 10% tow ball weight is also discussed.
https://outbacktravelaustralia.com.au/driving-towing-towing/towball-weight-and-trailer-stability/
Alan
B and A I'm sure that you will have noticed that posters are not going anywhere near this post. Funny that???
-- Edited by Magnarc on Saturday 9th of May 2020 01:47:35 PM
My take on Brenda & Alan's OP is that the towball mass is not reduced at all. That mass is now distributed to the van wheels as well as the tug and that is exactly what a WDH is designed to do. Basic physics would tell you the ball mass can not "go away" or be changed it can only be distributed to somewhere else by the use of devices like WDH.
lets see if we will need some popcorn??
Frank
Steve,there is no need to panic! On the very day that Alan posted this,I sent him a PM saying that I would not dignify his post by responding to it.In my email I explained exactly how a WDH works,and showed that a WDH does not,never has and never will change towball weight.I explained that there were so many holes in the post that it would take me a day to respond.A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATM also is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change.Simple physics at work! Since I have received neither acknowledgement nor reply,I can only surmise that my detaied explanation has again helped someone understand the workings of a WDH? But I must admit that I know absolutely nothing about "a rash on a hookers privates! Cheers
When I purchased my current van, I measured the height of the rear of the tug, connected the van and measured again.
The back of the tug had dropped 60 mm, the van looked nose down.....tug nose up.
Put the WDH on and the back of tug went up 50 mm, van and tug looked to be sitting nice and level.
To me, the steering was how it should be, it towed really well, not overweight and no swaying.
A lot of toing and froing regards the use of them, but I'm happy with mine..........do you have one Yobarr?
Cheers Bob
Hi Bob.....I am happy that your WDH has done what you wanted to achieve,but I do not use one,although there is an HR example in my shed.If the sole reason for using a WDH is to level the car,they may be a good thing,but unfortunately,in the vast majority of cases,the WDH is used in an effort to make a car do things for which it never was designed.The main problem faced by many caravanners is the overloading of the car's rear axle,with the WDH being seen as a "cure all",but it can create as many problems as it solves....think "oversteer". Buying the right car,or indeed,the right van,is the secret.With my car,I run at 6800kg GCM,legal on all axles,and no WDH,because I did my research before buying.There is 1350kg on the front axle,2300kg on the rear axle,and the GTM (weight on van wheels) is 3150kg.The car is thus around 16% heavier than the car,and very safe.......little chance of the "tail wagging the dog" that often occurs when the van is heavier than the car.If safety is of any concern,the weight on the wheels of the car should be at least 10% greater than the weight on the van's wheels,with some experts preferring the car to be 20% heavier. Many people have little understanding of weights,and spend thousands of dollars on a GVM upgrade without undestanding what it actually does.One popular model is often given a GVM upgrade from 3350kg to 3800kg,but the rear axle carrying capacity increases by only 50kg.....yes,a miserable 50kg,yet the upgrade costs thousands of dollars.Why would you bother? Cheers
Yobbar this quote from your post shows you have not seriously looked at my post, but just rejected it.
"A WDH removes weight from the rear axle of the car,with around 70% of that weight being returned to the front axle of the car,whilst the other 30% is transferred to the van's axle group.I applauded Alan for acknowledging that GTM is thus increased,and said that all he now had to understand is that ATM also is increased,as towball weight does not change when a WDH is tensioned. With my car,using a WDH to remove 100kg from the rear axle resulted in the front of the car gaining 66kg,whilst the van's axle group gained 34kg.Thus GVM decreased 34kg,ATM increased 34kg,GCM remained constant and towball weight did not change."
You have forgotton that the 34 Kgs returned to the vans wheels is only a part of the towball weight, the rest is now on the tugs axles.So if you claim that the ATM of the van has increased by 34Kgs the GCM of your rig would have increased by this amount also. Obviously this can't be. So the ATM of the van can't have increased.
Check my post again. All the weights I have used in the example come from a demo weighing by Haymen Reece themselves and is attached to the original post. I can assure you the arithmetic is correct. The weight on the tugs axles transmitted there by the weight on the towbar is 160Kgs, the increase in GTM of the van 60Kgs. the sum of these two weights is the original towball weight.
Don't bother sending me another PM unless you can discuss this issue rationaly unlike your last.
Alan
Its all just fun guys.
-- Edited by iana on Wednesday 13th of May 2020 06:01:30 PM
If you don't understand the terminology there is little hope of explaining anything sensibly.
Cheers,
Peter
Hi Peter....I absolutely do understand the terminology,but I do always try to simplify things for those who have absolutely NO understanding of the basic physics involved in the equation.Tomorrow,when I have more time,I will again attempt to help Alan understand that towball weight NEVER changes when a WDH is tensioned.NEVER.All weight transferred is removed from the car's rear axle,(NOT the towball) with a percentage of this,usually about 70%,being transferred to the car's front axle,and the remaining 30% being transferred to the van's axle group.The reason for using the term "about" is that the weight transferred depends on several things,such as the wheelbase of the car,the TBO (distance from rear axle to hitch point) and the distance from hitchpoint to van's axle group. TOWBALL WEIGHT NEVER CHANGES when a WDH is tensioned.Period.The confusion of people like Alan doesn't really bother me,with my major concern being that the misinformation they post may cause "newbies" etc to make decisions that endanger not only themselves and other road users,but may cause any insurance claim they need to make to be denied when their insurance company determines that they were overloaded,and unsafe.But ignorance is bliss.Cheers
P.S "Towball listed as zero,but not measured",surely makes a mockery of all submitted figures?
This argument is worse than the Corona Virus - it just keeps coming back ... and everyone is sick of it....
If you are not interested then it is a simple thing to simply BUTT OUT and stop winging because that is worse.
Cheers,
Peter
Kerry....as Peter has advised,there is no compulsion to read this,or indeed any,thread.Because you have an obvious interest in this subject,you will have noted that these posts invariably are started by people who have little understanding of the physics involved,but post anyway.The reason that replies are posted by those of us who do actually understand is to try to prevent "newbies" and others from being mislead,or falsely reassured that what they are doing is indeed legal and safe.In many cases,it is not.The reason that I participate in these "discussions" is solely to correct the misinformation........perhaps misunderstandings..............often posted by people who no doubt have good intentions but little apparent comprehension of the actual physics involved.Unlike other topics,when discussing weights there is no room for opinion.....weights are either right or they are wrong.Because of the frequent conflict in these "discussions" I sometimes choose to PM members,@and by doing this I have helped several to acquire a good understanding of weights,unsuitable cars,and the real effects of a WDH.My hope is that you now understand our motives,but I will again point out that threads such as this are rarely started by those of us who do know what we're talking about.....we have nothing to prove! Cheers
Alan....this post again illustrates that you are well and truly lost in the WDH wilderness.There are so many holes in your "logic" that it will take me hours to explain,but in the 7th line of this post you again say "..the 34kg returned to the van's wheels is only a part of the towball weight...". It seems that you still do not understand that that 34kg was NEVER part of the towball weight.The 34kg was transferred from the car's rear axle along with the 66kg that was returned to the car"s front axle.Later today I will try to find a couple of hours to PM you a detailed analysis of your post,pointing out the mistakes/misunderstandings,but in the meantime you may like to ponder why your original,post states that towball weight is "...listed as zero. (but not measured)".This certainly is convenient for your arguement,but is a nonsense.Cheers.
So far this year I have tried to ignore your posts Yobar but you are really one very rude, self opinionated dude.
You tell us all on here your know more than vehicle manufacturers, approved secondary vehicle manufacturers and now you know more than a major WDH manufacturer.
I have asked this of you many times before, SHOW US YOUR CREDENTIALS which make you correct and the others wrong.
Brenda and Allen,
He has done exactly that and ignored what you said, and it is funny because that is the very action that he accuses all others of doing when they dont agree with his drivel.
I cannot for the life of me see why he is still permitted to contribute on here. I am now thinking it can only be for the entertainment value.
There is a link to video that explains fully with weighbridge proof of the effects of a WDH. It is on UTube for any that may be interested. If I find it today I will provide the link.
The problem that anyone has when they mention anything to do with WDH or approved secondary vehicle modification is that you, Yobar, need to justify to all on here, your decision by choosing not to have these mods.
Cheers
Ivan
This is a list of the more common towing misconceptions.Of particular relevance to this thread is the explanation,in the third topic,that a WDH does NOT change towball weight.Simple physics at work.Some members might also like to take particular note of the sad truth revealed in the first topic? Cheers..
Here are Ian, I will share with ya mate.
I am have no credentials in this field but as a novice and for the sake of towing safety some "facts" on this subject do interest me.
So, as only a well credentialled Googler and after a quick search, I have discovered that yobarr's list of 4 items is simply part of a list 8 items contained in an article entitled "Top eight towing myths busted" and published on the reputable Australian Cars Guide website at this address: https://www.carsguide.com.au/tradies/advice/top-eight-towing-myths-busted-73044 . Yes I know that this may be just one person's opinion, but that person is Mark Oastler, who is a long time, reputable, Australian motor sports commentator. I would not think he would publish such an article without some technical advice to back him up, whatever/whoever that might be, nor would Cars Guide's duty of care/safety allow its publication without any such basis?
Again, a specialist WDH website of Alko, regarded as a "holy grail" of caravan engineering and accessories very clearly says on this link, http://www.withoutahitch.com.au/caravan/set-weight-distribution-hitch/# , that:
"When a weight distribution hitch is tensioned, the back of the vehicle and the front of the caravan are raised, with a portion of the load shifting to the front of the vehicle. It might then seem logical to assume that the ball weight has been reduced, but this is not the case. Without a weight distribution hitch fitted, the towbar assembly would just have a simple downward force imposed on it by the caravans coupling. But when a weight distribution hitch is fitted, it requires for that same towbar assembly to twist forward. The towbar is therefore not dealing with less weight when a weight distribution hitch has been attached and tensioned."
And finally, this link to the specialist caravan website, GoRv, https://www.gorv.com.au/weight-distribution-hitch/ , written by a well known guru and author in the caravan towing field, Collyn Rivers, seems to also debunk the so called myth about WDH and towball weight when among other things Collyn mentions:
"Called a weight distributing hitch, it levered up the rear of that tow vehicle, and levered down the front of that vehicle, in effect lessening some of that tow ball weight on the tow vehicles rear tyres to restore that on its front tyres. A smaller amount was also transferred to the caravans tyres." There are other websites that make a similar comment. Perhaps such comments support the Cars Guide myth buster as well as yobarr's contention that it is the tow ball's weight on the rear axle that is being transferred, not the weight bearing down onto the tow ball itself? This is just my layman's conclusion from after reading the above two references.
So before we all "shoot the messenger" (yobarr?), argue ourselves to death and as well as make suggestions about banning a member who refuses to roll over on a subject that he is clearly passionate about, perhaps all posters can provide their own link(s) to any reputable source which backs up any data and comments they make on this technical subject. Then we can all read the links and make our own objective conclusions?
Cheers,
Phillip
PS: When and if there is a 2021 Sydney Caravan Show, I shall ask the Hayman-Reece WDH specialisit conducting the demo there what facts and documentation he can put me nto that might debunk or back-up the so called myth!
-- Edited by Amigo1 on Thursday 14th of May 2020 11:52:22 PM
-- Edited by Amigo1 on Friday 15th of May 2020 10:44:57 AM
-- Edited by Amigo1 on Friday 15th of May 2020 10:46:41 AM
I have refaimed from commenting on this thread for hope it would remain amicable.
On another forum as soon as one appears the anti WDH brigade hops on to the thread and makes stupid comments about them as being band aids etc etc, I have even asked some of these people to provide us with their personal experiance in the use of a WDH, none has been forthcoming.
So would like to put the to you the anti WDH posters, your negative comments serve no purpose in assisting those who ask questions about their use or suitability, likewise my responses are about my personal experiance and research I have made, I do not expect every combination to have a WDH, however one will never know if they do or do not need to use one unless their coupling and ball heights are not setup correctly.
Initally you dont need to know ball weights, axle weights or towball overhang to assess, if you require the services of a WDH.
A good starting point is to read your owners manuals towing section and if the manufacture has a towing guide consult it for their recomendations, some demand the use of a WDH others forbid their use with others offer no reccomendation one way or the other, at the end of the day it's up to you if you need one or not.
One responder suggested following the advice of the person he named, I have found when asking that person specific questions about the use and application of weight distibution hitches, his responses were all based on theroitical data, when pressed about praticial experiance he retreated from the conservation, just like he did when he was a supporter of SAE's J2807 document where he and others took a single testing control and extrapoulated that to be a reccomundation applied to all WDH's retrospectivly.
Now going back to the OP whislt I am a supporter of the use of weight distribution hitches, there is a problem with these presentations as they are primarlily designed to sell their products, they mislead punters because they are in a controlled enviroment and are devoid of reality.
Lets go to reality the punter buys a vehicle he perceives to be suitable for towing the van of his choice, generally he has no idea about the weights of his vehicle other than it can tow 3500kg because thats what the advertising and salesman said it could, as for the van he can the little compliance plate which gives him the ATM, GTM and Tare(the tare is a fictious number). The salesman at van dealer if he's any good he will up sell you a few items which you may or may not need, one of them could be a WDH.
You have got your new tow vehicle and van home where you load them up with all sundry of items, then you hook them together, oh! crikey, the arse of the tug is down low and nose of the van is there to. At this point in time you do not know you axle weights nor the GVM or GCM along with your ball weight and actual GTM and ATM, or you may be lucky enough to have it all look pretty good.
If you have the former you may proceed to adjust where things are loaded in both units to make it look pretty good, you may decide to use that WDH you brought, one would hope you follow the instructions as supplied with it. Now everthing look real good we have an approximate idea of our ball weight because that salesman sold us one of the towball scales, now is the time we should go to the weighbridge and weigh everything, does that happen maybe maybe not.
This is where reality and fiction differ to get to the weighbridge if are required to use a WDH you need to set it up using the measurement system and then get to the weighbridge to confirm your weights and make any neccessary adjustments that are needed, unless you have a weighbridge in your backyard.
-- Edited by Gundog on Friday 15th of May 2020 10:44:47 AM
Hi Graham...it is not often that I agree with your representations,but you are to be commended you for this GREAT post.As you suggest,the ONLY way to get your weights right is to visit a weighbridge and conduct a series of tests.This is how I produced the figures I have already posted on this forum, showing that a WDH has NO effect on towball weight. Cheers.
Yes you are correct a WDH has no effect on towball weight.
Likewise towball weight becomes irrelevent when tow vehicle and caravan are connected, all that matters thereafter are the GCM, GTM Axle Weights and the towing capacity of the the tow vehicle.
No body has mentioned "Center of Gravity". If we were to take a single axle van with an ATM of 2500kg, and the center of gravity (which I will call C of G) was at a point vertically above the axle, the ball weight would be zero.
With the draw bar (hitch point) set at the horizontal, which I will call zero degrees, a set of scales at the hitch would read O kg. If some of the weight in the van was moved forward, the scales would begin to read, as the C of G moves forward. Now the hitch is sharing some of the load. By moving more of the internal cargo load forward, so that the ball weight now reads 250 kg, the C of G will have moved forward, by how much would depend on the van, and I would have no idea where the C of G point is.
We can now say the Ball weight is 250 kg with the hitch point at 0 degrees to the horizontal.
If you hitch the van up, and the weight of the draw bar causes the back of the vehicle to drop, the draw bar is no longer at 0 degrees, it is now maybe -2 degrees, the van has rotated about its axis (in this case the axles), and the C of G has moved forward. The hitch will now be sharing more of the van load. The ball weight has increased, it is now maybe 260 kg.
If you now use some method to raise the tow ball using heavier rear springs, air bags, or WDH, so that the hitch is now back to zero degrees to the horizontal, the load sharing of the hitch will be back to 250 kg.