Greg, it is indeed a great post that I will study at length when I get a minute. Cheers.
Ivan 01 said
03:53 PM Aug 21, 2022
yobarr wrote:
This is becoming interesting! It would take a lot of "creative" measuring to convince yourselves that a WDH increase TBO by only 50mm, but I have started compiling a response. Stephen's theory is flawed too, as weight on the rear axle tends to limit yaw, but today is beer-drinking day so I cannot apply the concentration needed to respond. Maybe by tomorrow we'll have further interesting comments, along with perhaps more sheep-like "+1s" from those who seem to have nothing of substance to add. Cheers
P.S For a start I'll post this photo of a shank. Anybody who believes that a WDH shank and the associated tow head adds only 50mm to the distance from the end of the receiver to the ball is delusional. Cheers
-- Edited by yobarr on Sunday 21st of August 2022 03:32:33 PM
- 1 ^^^^
Just to balance the ledger Yobarr,
Enjoy your beers.
Are We Lost said
04:59 PM Aug 21, 2022
yobarr wrote:
<snip>
It would take a lot of "creative" measuring to convince yourselves that a WDH increase TBO by only 50mm,
<snip>
OK, I just measured mine at about 85mm more. I did say similar. But 85mm difference in a 3200mm wheelbase is hardly a reason for concern. And the point I was making was prefaced with ......
"But even for those with greater overhang, what you failed to take into account is the compensating benefit of the WDH in reducing the risk of yaw."
So please don't waste your effort focusing on the 50mm (or 85mm) part. Please focus on how yaw acts with a pivot point on the rear axle, and the effects on tyre grip with different weights. After all, that is the point of the discussion isn't it?
-- Edited by Are We Lost on Sunday 21st of August 2022 06:32:11 PM
Bobdown said
07:31 PM Aug 21, 2022
All good posts....Greg, Ivan, Gundog and AWL, but I feel you are wasting your time.
It's either a 79 series with no WDH or the highway with Yobarr, he will not listen to anyone else's opinion, however correct you may be.
Cheers Bob
Craig1 said
08:28 PM Aug 21, 2022
I just measured my Hayman Reece V standard Tojo and it is either 49, 50 , or 51 mm extra length.
Are We Lost said
08:38 PM Aug 21, 2022
Bobdown wrote:
All good posts....Greg, Ivan, Gundog and AWL, but I feel you are wasting your time.
It's either a 79 series with no WDH or the highway with Yobarr, he will not listen to anyone else's opinion, however correct you may be.
Cheers Bob
I have no doubt you are right. But others will read his comments and without anyone contradicting him may well believe what he says.
One thing for sure ... there will be no response from Yobarr that attempts to explain the physics of it.
And thanks to the others for the positive comments on my explanation.
yobarr said
08:57 PM Aug 21, 2022
Are We Lost wrote:
OK, I just measured mine at about 85mm more. I did say similar. But 85mm difference in a 3200mm wheelbase is hardly a reason for concern. And the point I was making was prefaced with ......
"But even for those with greater overhang, what you failed to take into account is the compensating benefit of the WDH in reducing the risk of yaw."
So please don't waste your effort focusing on the 50mm (or 85mm) part. Please focus on how yaw acts with a pivot point on the rear axle, and the effects on tyre grip with different weights. After all, that is the point of the discussion isn't it?
Pray tell me how you think that removing weight from the rear axle reduces the effects of yaw. And how do you think a WDH reduces risks of yaw? As you suggest, the rear axle is a pivot point, so it needs to have as firm a grip on the road as possible. Appropriate tyre pressure is critical. Cheers.
-- Edited by yobarr on Sunday 21st of August 2022 10:12:29 PM
Ivan 01 said
09:26 PM Aug 21, 2022
yobarr wrote:
Are We Lost wrote:
OK, I just measured mine at about 85mm more. I did say similar. But 85mm difference in a 3200mm wheelbase is hardly a reason for concern. And the point I was making was prefaced with ......
"But even for those with greater overhang, what you failed to take into account is the compensating benefit of the WDH in reducing the risk of yaw."
So please don't waste your effort focusing on the 50mm (or 85mm) part. Please focus on how yaw acts with a pivot point on the rear axle, and the effects on tyre grip with different weights. After all, that is the point of the discussion isn't it?
Pray tell me how you think that removing weight from the rear axle reduces the effects of yaw. And how do you think a WDH reduces risks of yaw? As you suggest, the rear axle is a pivot point, so it needs to have as firm a grip on the road as possible. Appropriate pressure is critical. Cheers.
-1 again yobarr
You did say this in another post:
P.S For a start I'll post this photo of a shank. Anybody who believes that a WDH shank and the associated tow head adds only 50mm to the distance from the end of the receiver to the ball is delusional.
Are you having a bet both ways now.
Is it overhang or is it weight distribution that is creating this imaginary instability.
From my observation you failed to read and understand Are We Losts post and my guess is because you just dont want to understand it.
A line or two drawn on a tow bar tongue of a dubious load rating with regard to compliance is by no means an accurate method of indicating tow ball overhang.
My son has a WDH with a bracket that fits directly under his tow ball on his absolutely genuine and rated tow bar tongue on his Toyota which provides the mounting for the load distribution bars and this system does not extend the tow ball overhang at all. Read that again Yobarr, not even 1 millimetre.
I might suggest that you are aware of this design but have conveniently forgotten about it as it doesnt provide the overhang you require to rant and rave about physics and statistics,
Go and have another beer, it should solve most problems.
We can only hope that those like the OP in this topic stay with us through the nonsense created to read the posts which are stating the facts.
-- Edited by Ivan 01 on Sunday 21st of August 2022 09:37:31 PM
yobarr said
09:54 PM Aug 21, 2022
Just scaled this HR WDH as best I could with wooden ruler, and it is at least 206mm from last hole in shank to extremity of shank. And we haven't yet fitted the adjustable head unit for the towball, so we're going to have the towball around 300mm from the last hole in shank. Cheers
Thought I would drop in this evening. It's been a while. Oh dear. Here we go again. Another WDH argument.
Once again: Good members being verbled. Condescending statements. Repeatedly saying none of the members "understand basic physics". Obviously suggesting members are stupid. Refusing to accept almost any car out there is capable of towing heavier vans safely. Except his of course. Refusing to accept that others opinions often make sense. NEVER NEVER, NEVER wrong. Lol A piece of legal equipment (WDH) thats use is recommended by many car makers & used by Millions overseas and in AU is useless. In fact makes rigs "un-safe". Uploading typed information or statements without saying where it was obtained. So, could be true could be false. Up loading images that are not only irrelevant but often give the wrong impression or even misleading. One minute Hayman Reese is publishing rubbish next, uses there documents to support his arguments. Yet on other forums discussion happens with politely without this nonsense. And a WDH is generally accepted as a good thing and has its place.
Good members leaving or now rarely posting.
When will it end? When will all those "silent" members feel it's worth while returning?
When will someone take decisive action?
Will I ever return?
Cheers. OB ;)
https://youtu.be/s8wxsUv_2vg
-- Edited by oldbloke on Monday 22nd of August 2022 12:27:40 AM
gold dandelion said
11:32 PM Aug 21, 2022
I think it is pretty pathetic the goings on about weight transfer etc, it appears to me most people with good intentions or not, either believe they are right or the opposites are wrong and can't prove either way. Do we really care, as long as the tow rig tows well, is safe and in the rules of safety, or close to it, remembering we have all driven at 80kph in a 60 kph zone so have broken the rules somewhere. I did drop off this forum for awhile, as some have suggested it is cancerous, I tend to agree some what, the behavior and responses are childish and the keyboard retaliation is pretty pathetic, who knows the person you are slandering is probably the person you are having a beer with in the camp kitchen. It used to be comical coming back on here now and again, now it really is childish and pathetic. grow up. And remember if you slander me I may catch you in the camp kitchen, if you do have friends and do mix.
Robert.
Greg 1 said
12:02 AM Aug 22, 2022
Yobarr, with regards the 50mm, the measurement relates to the additional distance that my WDH head extends further than the standard Ford Ranger tongue that is part of the vehicles standard equipment.
If you place them side by side lining up the hitch pin holes, the distance between the centre line of the ball shank holes is a difference of 50mm.
So over and above the Ford designed tongue for their 3500kg rated towbar my WDH contributes 50mm extra to TBO.
With regards your comments regarding keeping load on the back axle to stop yaw, you also want to reduce push. Have you heard of that term?
All production vehicles are designed around having a slight push or understeer condition as this is considered as a safe way to set the vehicle up.
However, when you add a van on the back you immediately take weight off the front axle and exaggerate the the understeer or push tendency which is then an issue. It stops good steering response and with 75% of a vehicles braking being done by the front wheels, reduces the braking efficiency. All bad.
By placing some of the lost weight back on the front axle, some of the loss of control and braking is restored. It hasn't removed all the weight off the rear axle, in fact the rear axle will still have more weight on the rear than in its vehicle on its own status. We are not talking about removing so much weight off the axle that we then induce an oversteer condition. We are just fine tuning the suspension to give the best handling possible with a van on the back.
We do much the same on a race car with adjustable suspension. By corner weighting the car by adjusting the spring perches so that we even up what each wheel is carrying and by adjusting the anti roll bars we can induce or remove understeer or overseer to suit a track or driver.
We soften off the spring settings and the shock absorber settings to allow for a wet race.
While we cannot do all of that to our van and tow vehicle, we can do a couple of things to improve the handling. Where we place payload to start, the tyre pressures we run and we can play with those a little to improve handling, and we can utilise a WDH to fine tune it.
It is an excellent aid to this but mate you have a fixation that these are evil and that anything other than a D035 hitch is also an invention of the devil despite dozens of us having proven the worth of the WDH and other products over years of towing.
I think you just need to let the matter rest for the sake of peace on the forum.
Dougwe said
07:47 AM Aug 22, 2022
All above is proof that we need to change to discussing Generators or even electricity (wind) farms, Hi Craig
Gee, I can remember back many moons, many, when 27 good long time members left this great forum due to 2 complaints. Maybe, just maybe, it's time to reverse that and 1 go to save 27
There is a special spot in Techies called 'Sub Forums' for all this discussion and those not wanting to read all the dribble from the resident Xspurt can dribble away but no, it's everywhere you look.
I have great respect for Cindy and all she has done and is doing with the GN's. Over the years I have had fun, learnt heaps and met many members and the forum helped get me through some bad times in my life. That said, one thing maybe Cindy could do is move these OFFENDING threads to the right place. If an argument breaks out, delete it not just lock it. It makes the forum look bad.
Bugga! I thought I fixed my soap box but nope.
Keep safe out there everyone.
Ivan 01 said
08:42 AM Aug 22, 2022
Old Bloke
Good to see you back in here again. Yes, it hasnt changed.
Gold Dandelion, You are correct, it is annoying that the topics of weights always end up in arguments deletions and locked threads when they could be a valuable resource for the forum. The real fact is that all this has been proven on a weighbridge. If safety was at all doubted then these modifications would be illegal and most certainly NOT be recommended by many vehicle manufacturers.
Greg 1,
Another very informative post above with real facts from you. Your participation is a credit to you and to this forum. At times it is extremely difficult to compete with comments so condescending as to ridicule many on the forum and in some cases even the poor fellow OP that only asked a question.
Are We Lost
Your input has been excellent in all topics WDH. My comments to Greg most certainly apply to you as well.
Dougwe
I guess that you of many members have a reason to voice your distaste. Your time and contribution on here is testament to your concern. Many people have left due to this constant bombardment of mainly false information provided by someone who has one agenda and that is to ensure we all know how *smart* this member is with the choice of the only vehicle made for towing ( his opinion ). There are others which come to mind who are still on here but have decided not to participate in the arguments with the unqualified due mainly to the stress caused to themselves. Unfortunately the forum loses again, most are sick of arguing with the *forum expert* There are other forums that have made the sensible move to eliminate the problem to the advantage of all the members.
My thoughts are that over the years I have posted my views on WDH systems and to an end I tried my hardest to be as civil and friendly as possible but to no avail as he continually *poked the bear* until again, I was drawn into his nonsense.
My bad..
My bad for re entering the fray. (again.)
-- Edited by Ivan 01 on Monday 22nd of August 2022 08:49:50 AM
dogbox said
08:53 AM Aug 22, 2022
if you do not like/agree with what a person posts do not respond to their posts on the offending subjects an they will fade away
Ivan 01 said
09:11 AM Aug 22, 2022
dogbox wrote:
if you do not like/agree with what a person posts do not respond to their posts on the offending subjects an they will fade away
Hi dogbox,
In theory you are absolutely correct.
Unfortunately when it comes to another members safety, bad advice should be discouraged and the quoting of actual facts is the only way to try and ensure that those seeking that advice are actually receiving correct information and not the personal belief of someone whose main agenda is to promote the selection and use of a certain make and model vehicle and then promote the non fitment of a device that is recommended by that same vehicle manufacturer to be used under certain circumstances.
If it wasnt so dangerous it would actually be funny. ( as in hahaha!, )
-- Edited by Ivan 01 on Monday 22nd of August 2022 09:31:04 AM
StewG said
10:27 PM Aug 22, 2022
Sorry fellas, I've run out of popcorn!
As rivetting as this discussion is, it is too repetitive for true enjoyment. Besides that, my tug manufacturer says do not use a WDH. So I don't. However, I do have to minimise the weight of contents in the boot to avoid exceeding the rear axle weight limitation.
Cheers!
oldbloke said
02:59 PM Aug 23, 2022
Craig1 wrote:
I just measured my Hayman Reece V standard Tojo and it is either 49, 50 , or 51 mm extra length.
I just measured mine.
HR WDH 280mm
STD factory supplied 205mm
75mm extra for the HR WDH. A miniscule amount in the scheme of things.
Of course each brand will be slightly different.
littledick said
03:25 PM Aug 23, 2022
We have a 2017 Ranger Wildtrak. Towing 3T. Use WDH but nothing done to the car.
No problem, don't see any need to upgrade anything after 5 years.
Dick.
Bukhouse said
02:16 PM Sep 10, 2022
Hi someone posted a caravan loading caculator on this posting and I cant find it anyone know off the caculator Im refering to
it was a excel document
Bobdown said
03:27 PM Sep 10, 2022
Bukhouse wrote:
Hi someone posted a caravan loading caculator on this posting and I cant find it anyone know off the caculator Im refering to
it was a excel document
I found these two that I'd downloaded Ken, one has someone's weights pre-loaded, the other one has all the sections across the bottom line.
When people argue the physics of a subject and at the same time ignore mass when discussing how two linked masses behave I begin to wonder.
Another thing is that I would imagine that caravans with an ATM of 3000kg and up would have double axles rather than single.
The lowball weight of my double axle 3000kg ATM caravan is 164kg according to the manafacturer.
Today I drove down the hill from Toowoomba to Ipswich. When I stopped at the bottom to fill up at the Freedom service station I checked all the wheel temperatures.
The car front pair were the hottest( touchable for about 5 secs or so) then the car back wheels, nowhere near as hot and the van wheels not even warm.
This is what I expected.
yobarr said
10:56 AM Sep 16, 2022
jegog wrote:
When people argue the physics of a subject and at the same time ignore mass when discussing how two linked masses behave I begin to wonder. Another thing is that I would imagine that caravans with an ATM of 3000kg and up would have double axles rather than single. The lowball weight of my double axle 3000kg ATM caravan is 164kg according to the manafacturer. Today I drove down the hill from Toowoomba to Ipswich. When I stopped at the bottom to fill up at the Freedom service station I checked all the wheel temperatures. The car front pair were the hottest( touchable for about 5 secs or so) then the car back wheels, nowhere near as hot and the van wheels not even warm. This is what I expected.
Hmmm. You do, of course, realise that the towball weight listed by the van manufacturer means nothing ... absolutely nothing? Assuming the generally accepted 10% towball weight, with a loaded 3000kg ATM caravan your towball weight would be around 300kg. As an aside, your brakes are incorrectly set up if the front wheels are "hot" and the van wheels "not even warm". Cheers
-- Edited by yobarr on Friday 16th of September 2022 10:57:30 AM
Are We Lost said
02:21 PM Sep 16, 2022
Jegog, this is one of the times I mostly agree with Yobarr. The plated towball weight from the manufacturer (if accurate) is the weight as it left the factory, empty. There is the occasional van that has a towball limit stamped but these are not common. When you load the van the towball weight will change according to how the load is distributed. The positioning of water tanks has the most impact on the result. A good outcome is for around 10% of the van's laden weight to be on the towball. Only a weigbridge will tell you what it is.
As for the hot and cold brakes, it is best if they all work together. The tow vehicle front brakes will usually get hotter than the rears as they typically do more work. When going down a long descent I like to share more of the load with the van brakes by adjusting the sensitivity up a bit. That way, the most capable brakes (the tow vehicle front) have reserve capability in case higher intensity braking is needed. It may be a bit of trial and error, stopping and feeling the hubs to work out a good balance.
For example, if on a long descent and a particularly steep section comes up and you need to stop, it's nice to know that the best brakes still have plenty of reserve before fading due to overheating. Of course engine braking should be used as the primary braking force. Watch the transmission temperature in automatics on long descents.
jegog said
09:54 PM Sep 16, 2022
I mentioned people not understanding the behaviour of couples masses.
Remember mass is omnidirectional so when traveling along the road a 3000kg tug towing a 3000kg van acts as a 6000kg force in the direction of travel.
There is also a 6000kg force acting downwards caused by gravity and a 6000kg force b y the road acting upwards countering the grab its induced force.
When braking, the inertia will try to prevent the vehicle and van from reducing its forward velocity. Therefore the front brakes are always going to do the lions share of the braking.
The front brakes are acting against the full 6000kg mass's inertia.
The back brakes are mainly acting against the van mass's inertia and a small portion of the vehicle mass's inertia.
The caravan brakes are mainly acting against a portion the van mass's inertia.
Therefore, the vehicle front wheels do most of the braking, with or without towing a van; and the vehicle will also do most of the braking.
The above is based upon the basic physics taught to me over 60 years ago.
As for the generally accepted 10% tow-ball weight, I think that that is just someone's thought bubble which has been perpetuated by so called experts who have no idea of what they are talking about.
All(2) of the research on towed trailer stability that I have seen, have found that a lesser percentage is better. One researcher using a caravan recommended 5 to 7 percent and the other using a configurable trailer recommended 6 to 8 percent.
I have lost the link to the first but the link to the second research paper is attached.
So instead of 10% let's settle for 6 or 7%, based on science.
I mentioned people not understanding the behaviour of couples masses.
Remember mass is omnidirectional so when traveling along the road a 3000kg tug towing a 3000kg van acts as a 6000kg force in the direction of travel.
There is also a 6000kg force acting downwards caused by gravity and a 6000kg force b y the road acting upwards countering the grab its induced force.
When braking, the inertia will try to prevent the vehicle and van from reducing its forward velocity. Therefore the front brakes are always going to do the lions share of the braking.
The front brakes are acting against the full 6000kg mass's inertia.
The back brakes are mainly acting against the van mass's inertia and a small portion of the vehicle mass's inertia.
The caravan brakes are mainly acting against a portion the van mass's inertia.
Therefore, the vehicle front wheels do most of the braking, with or without towing a van; and the vehicle will also do most of the braking.
The above is based upon the basic physics taught to me over 60 years ago.
As for the generally accepted 10% tow-ball weight, I think that that is just someone's thought bubble which has been perpetuated by so called experts who have no idea of what they are talking about.
All(2) of the research on towed trailer stability that I have seen, have found that a lesser percentage is better. One researcher using a caravan recommended 5 to 7 percent and the other using a configurable trailer recommended 6 to 8 percent.
I have lost the link to the first but the link to the second research paper is attached.
So instead of 10% let's settle for 6 or 7%, based on science.
This post shows a very limited understanding of weights and dynamics. Perhaps you could explain why huge semi-trailers in Canada, for example, have NO front brakes? You may get away with 6%-7% towball weight on shorter, lightweight caravans behind heavier cars, but not with a "typical" Australian van behind a lightweight twin-cab or such. You can't simply decide you'll defy the simple laws of physics.Cheers
jegog said
10:41 PM Sep 16, 2022
Jobarr, I take it you didn't read the paper.
You talk about weight when the M in ATM and GVM stands for mass, not weight.
Are you saying that all, repeat all, semi-trailers in Canada are not fitted with front brakes.
According to Transport Canada They are required to have brakes.
I assume that semi-trailers are covered by the attached document, if not Yobarr, maybe you could provide the Transport Canada document which covers semi-trailers and show that they do not need brakes on their front wheels.
Therefore, the vehicle front wheels do most of the braking, with or without towing a van; and the vehicle will also do most of the braking.
The above is based upon the basic physics taught to me over 60 years ago.
<snip>
Yes, I agree that the vehicle design does have most braking on the front wheels. But having the van brakes doing practically nothing is not the best strategy.
The best would be for each axle to contribute an equal percentage of it's braking capability (based on grip on the road), so that all wheels shared the task. In the case of an emergency stop it would be pretty silly to have the tow vehicle skidding (or ABS activating) while the van brakes are just loafing along. Not having that additional braking capacity could mean the difference between stopping in time, or 5 metres after you hit something.
Or, as you round a bend there is water on the road. With most of the braking on the tow vehicle front wheels they are much more likely to lock up. With the braking shared across all wheels, less likely.
But all this misses the point I was making about reserving the best brakes in case they are really needed. 60 years ago we didn't have the ability to control the van braking with a knob on the dashboard. Now that we do, why not use it?
I'm not going to respond to the 10% towball issue as there has been plenty of discussion on that.
-- Edited by Are We Lost on Friday 16th of September 2022 11:04:04 PM
jegog said
12:00 AM Sep 17, 2022
yobarr wrote:
Hmmm. You do, of course, realise that the towball weight listed by the van manufacturer means nothing ... absolutely nothing? Assuming the generally accepted 10% towball weight, with a loaded 3000kg ATM caravan your towball weight would be around 300kg. As an aside, your brakes are incorrectly set up if the front wheels are "hot" and the van wheels "not even warm". Cheers
-- Edited by yobarr on Friday 16th of September 2022 10:57:30 AM
Well that says it all, you know better than the manufacturer. What arrogance?
For your information Jobarr, my caravan is a dual axle torsion bar suspension system.
Increasing tow-ball weight moves the van centre of gravity towards the front of the van.
Weight is moved off the back wheels and onto the front wheels when the tow-ball weight is increased.
Increase the tow-ball weight too much and the load on the front tyres could exceed the tyres rating.
Which is not something we want to do.
So I will be ignoring your erroneous advice and heeding the caravan manufacturer.
Greg 1 said
01:29 AM Sep 17, 2022
I have to say that in this instance I do agree with what yobarr is trying to say here.
And I have read the study that you have posted jegog.
I will make some points as to why in my opinion, yobarr is correct.
1. The tow ball mass as shown on your compliance plate as given by the manufacturer refers to the tow ball down load in an unladen state, and so is as useless as tits on a bull with regards the vans final weights fully laden and the rigs final stability..
The manufacturer has no real idea of the final tow ball weight other than the laden TBW should be roughly within a range and that, in this country, is recommended to be between 8% and 12%.
This percentage has been arrived at by various vehicle engineers and licensing authorities in this country as a target TBW.
Remember that the study in question was done in Britain with very light trailer mass and being towed by light cars with very light rear axle loadings, so for their common conditions, this study makes sense. They recommend a TBW of 6 to 8% which for the very light van in question is going to be somewhere about right
2. Australian vans are generally larger and much heavier than their European counterparts and are normally towed with 4WD vehicles that have greater mass and higher axle loads plus suspension much better suited to towing, so having the van load slightly nose heavy is a good thing.
It increases van stability and although it places slightly more load on the vans front wheels, if you check the weights on the axle groups on a well balanced rig, it is not enough to be of any concern.
The target of 10% TBW is a reasonable figure to aim for to maintain good stability.
The much heavier vans we see in this country have much greater yaw enertia than the light Euro vans.
3.A van which has its axle group positioned rearward of the centreline will inevitably produce a more stable rig as this increases the distance from the tow hitch. The study confirms that.
This however will also increase the TBW and it will tend to move the C of G forwards which is where you want it.
In all the vans, trailers and horse floats I have towed about the country, having the loaded weight giving a slightly forward C of G has always resulted in a good towing and stable rig, regardless of the suspension system employed.
4. If you are concerned that a target TBW of 10% might unload the front wheels of the tow tugs then that's where the good old WDH comes in to fine tune the handling and braking.
Greg, it is indeed a great post that I will study at length when I get a minute. Cheers.
- 1 ^^^^
Just to balance the ledger Yobarr,
Enjoy your beers.
OK, I just measured mine at about 85mm more. I did say similar. But 85mm difference in a 3200mm wheelbase is hardly a reason for concern. And the point I was making was prefaced with ......
"But even for those with greater overhang, what you failed to take into account is the compensating benefit of the WDH in reducing the risk of yaw."
So please don't waste your effort focusing on the 50mm (or 85mm) part. Please focus on how yaw acts with a pivot point on the rear axle, and the effects on tyre grip with different weights. After all, that is the point of the discussion isn't it?
-- Edited by Are We Lost on Sunday 21st of August 2022 06:32:11 PM
All good posts....Greg, Ivan, Gundog and AWL, but I feel you are wasting your time.
It's either a 79 series with no WDH or the highway with Yobarr, he will not listen to anyone else's opinion, however correct you may be.
Cheers Bob
I have no doubt you are right. But others will read his comments and without anyone contradicting him may well believe what he says.
One thing for sure ... there will be no response from Yobarr that attempts to explain the physics of it.
And thanks to the others for the positive comments on my explanation.
Pray tell me how you think that removing weight from the rear axle reduces the effects of yaw. And how do you think a WDH reduces risks of yaw? As you suggest, the rear axle is a pivot point, so it needs to have as firm a grip on the road as possible. Appropriate tyre pressure is critical. Cheers.
-- Edited by yobarr on Sunday 21st of August 2022 10:12:29 PM
-1 again yobarr
You did say this in another post:
P.S For a start I'll post this photo of a shank. Anybody who believes that a WDH shank and the associated tow head adds only 50mm to the distance from the end of the receiver to the ball is delusional.
Are you having a bet both ways now.
Is it overhang or is it weight distribution that is creating this imaginary instability.
From my observation you failed to read and understand Are We Losts post and my guess is because you just dont want to understand it.
A line or two drawn on a tow bar tongue of a dubious load rating with regard to compliance is by no means an accurate method of indicating tow ball overhang.
My son has a WDH with a bracket that fits directly under his tow ball on his absolutely genuine and rated tow bar tongue on his Toyota which provides the mounting for the load distribution bars and this system does not extend the tow ball overhang at all. Read that again Yobarr, not even 1 millimetre.
I might suggest that you are aware of this design but have conveniently forgotten about it as it doesnt provide the overhang you require to rant and rave about physics and statistics,
Go and have another beer, it should solve most problems.
We can only hope that those like the OP in this topic stay with us through the nonsense created to read the posts which are stating the facts.
-- Edited by Ivan 01 on Sunday 21st of August 2022 09:37:31 PM
Just scaled this HR WDH as best I could with wooden ruler, and it is at least 206mm from last hole in shank to extremity of shank. And we haven't yet fitted the adjustable head unit for the towball, so we're going to have the towball around 300mm from the last hole in shank. Cheers
Thought I would drop in this evening. It's been a while.
Oh dear. Here we go again. Another WDH argument.
Once again:
Good members being verbled.
Condescending statements.
Repeatedly saying none of the members "understand basic physics". Obviously suggesting members are stupid.
Refusing to accept almost any car out there is capable of towing heavier vans safely. Except his of course.
Refusing to accept that others opinions often make sense.
NEVER NEVER, NEVER wrong. Lol
A piece of legal equipment (WDH) thats use is recommended by many car makers & used by Millions overseas and in AU is useless. In fact makes rigs "un-safe".
Uploading typed information or statements without saying where it was obtained. So, could be true could be false.
Up loading images that are not only irrelevant but often give the wrong impression or even misleading.
One minute Hayman Reese is publishing rubbish next, uses there documents to support his arguments.
Yet on other forums discussion happens with politely without this nonsense. And a WDH is generally accepted as a good thing and has its place.
Good members leaving or now rarely posting.
When will it end?
When will all those "silent" members feel it's worth while returning?
When will someone take decisive action?
Will I ever return?
Cheers. OB ;)
https://youtu.be/s8wxsUv_2vg
-- Edited by oldbloke on Monday 22nd of August 2022 12:27:40 AM
Robert.
All above is proof that we need to change to discussing Generators or even electricity (wind) farms, Hi Craig
Gee, I can remember back many moons, many, when 27 good long time members left this great forum due to 2 complaints. Maybe, just maybe, it's time to reverse that and 1 go to save 27
There is a special spot in Techies called 'Sub Forums' for all this discussion and those not wanting to read all the dribble from the resident Xspurt can dribble away but no, it's everywhere you look.
I have great respect for Cindy and all she has done and is doing with the GN's. Over the years I have had fun, learnt heaps and met many members and the forum helped get me through some bad times in my life. That said, one thing maybe Cindy could do is move these OFFENDING threads to the right place. If an argument breaks out, delete it not just lock it. It makes the forum look bad.
Bugga! I thought I fixed my soap box but nope.
Keep safe out there everyone.
Old Bloke
Good to see you back in here again. Yes, it hasnt changed.
Gold Dandelion,
You are correct, it is annoying that the topics of weights always end up in arguments deletions and locked threads when they could be a valuable resource for the forum. The real fact is that all this has been proven on a weighbridge. If safety was at all doubted then these modifications would be illegal and most certainly NOT be recommended by many vehicle manufacturers.
Greg 1,
Another very informative post above with real facts from you. Your participation is a credit to you and to this forum. At times it is extremely difficult to compete with comments so condescending as to ridicule many on the forum and in some cases even the poor fellow OP that only asked a question.
Are We Lost
Your input has been excellent in all topics WDH. My comments to Greg most certainly apply to you as well.
Dougwe
I guess that you of many members have a reason to voice your distaste. Your time and contribution on here is testament to your concern.
Many people have left due to this constant bombardment of mainly false information provided by someone who has one agenda and that is to ensure we all know how *smart* this member is with the choice of the only vehicle made for towing ( his opinion ).
There are others which come to mind who are still on here but have decided not to participate in the arguments with the unqualified due mainly to the stress caused to
themselves.
Unfortunately the forum loses again, most are sick of arguing with the *forum expert*
There are other forums that have made the sensible move to eliminate the problem to the advantage of all the members.
My thoughts are that over the years I have posted my views on WDH systems and to an end I tried my hardest to be as civil and friendly as possible but to no avail as he continually *poked the bear* until again, I was drawn into his nonsense.
My bad..
My bad for re entering the fray. (again.)
-- Edited by Ivan 01 on Monday 22nd of August 2022 08:49:50 AM
Hi dogbox,
In theory you are absolutely correct.
Unfortunately when it comes to another members safety, bad advice should be discouraged and the quoting of actual facts is the only way to try and ensure that those seeking that advice are actually receiving correct information and not the personal belief of someone whose main agenda is to promote the selection and use of a certain make and model vehicle and then promote the non fitment of a device that is recommended by that same vehicle manufacturer to be used under certain circumstances.
If it wasnt so dangerous it would actually be funny. ( as in hahaha!, )
-- Edited by Ivan 01 on Monday 22nd of August 2022 09:31:04 AM
As rivetting as this discussion is, it is too repetitive for true enjoyment. Besides that, my tug manufacturer says do not use a WDH. So I don't. However, I do have to minimise the weight of contents in the boot to avoid exceeding the rear axle weight limitation.
Cheers!
I just measured mine.
HR WDH 280mm
STD factory supplied 205mm
75mm extra for the HR WDH. A miniscule amount in the scheme of things.
Of course each brand will be slightly different.
We have a 2017 Ranger Wildtrak. Towing 3T. Use WDH but nothing done to the car.
No problem, don't see any need to upgrade anything after 5 years.
Dick.
Hi someone posted a caravan loading caculator on this posting and I cant find it anyone know off the caculator Im refering to
it was a excel document
I found these two that I'd downloaded Ken, one has someone's weights pre-loaded, the other one has all the sections across the bottom line.
Cheers Bob
Another thing is that I would imagine that caravans with an ATM of 3000kg and up would have double axles rather than single.
The lowball weight of my double axle 3000kg ATM caravan is 164kg according to the manafacturer.
Today I drove down the hill from Toowoomba to Ipswich. When I stopped at the bottom to fill up at the Freedom service station I checked all the wheel temperatures.
The car front pair were the hottest( touchable for about 5 secs or so) then the car back wheels, nowhere near as hot and the van wheels not even warm.
This is what I expected.
Hmmm. You do, of course, realise that the towball weight listed by the van manufacturer means nothing ... absolutely nothing? Assuming the generally accepted 10% towball weight, with a loaded 3000kg ATM caravan your towball weight would be around 300kg. As an aside, your brakes are incorrectly set up if the front wheels are "hot" and the van wheels "not even warm". Cheers
-- Edited by yobarr on Friday 16th of September 2022 10:57:30 AM
Jegog, this is one of the times I mostly agree with Yobarr. The plated towball weight from the manufacturer (if accurate) is the weight as it left the factory, empty. There is the occasional van that has a towball limit stamped but these are not common. When you load the van the towball weight will change according to how the load is distributed. The positioning of water tanks has the most impact on the result. A good outcome is for around 10% of the van's laden weight to be on the towball. Only a weigbridge will tell you what it is.
As for the hot and cold brakes, it is best if they all work together. The tow vehicle front brakes will usually get hotter than the rears as they typically do more work. When going down a long descent I like to share more of the load with the van brakes by adjusting the sensitivity up a bit. That way, the most capable brakes (the tow vehicle front) have reserve capability in case higher intensity braking is needed. It may be a bit of trial and error, stopping and feeling the hubs to work out a good balance.
For example, if on a long descent and a particularly steep section comes up and you need to stop, it's nice to know that the best brakes still have plenty of reserve before fading due to overheating. Of course engine braking should be used as the primary braking force. Watch the transmission temperature in automatics on long descents.
I mentioned people not understanding the behaviour of couples masses.
Remember mass is omnidirectional so when traveling along the road a 3000kg tug towing a 3000kg van acts as a 6000kg force in the direction of travel.
There is also a 6000kg force acting downwards caused by gravity and a 6000kg force b y the road acting upwards countering the grab its induced force.
When braking, the inertia will try to prevent the vehicle and van from reducing its forward velocity. Therefore the front brakes are always going to do the lions share of the braking.
The front brakes are acting against the full 6000kg mass's inertia.
The back brakes are mainly acting against the van mass's inertia and a small portion of the vehicle mass's inertia.
The caravan brakes are mainly acting against a portion the van mass's inertia.
Therefore, the vehicle front wheels do most of the braking, with or without towing a van; and the vehicle will also do most of the braking.
The above is based upon the basic physics taught to me over 60 years ago.
As for the generally accepted 10% tow-ball weight, I think that that is just someone's thought bubble which has been perpetuated by so called experts who have no idea of what they are talking about.
All(2) of the research on towed trailer stability that I have seen, have found that a lesser percentage is better. One researcher using a caravan recommended 5 to 7 percent and the other using a configurable trailer recommended 6 to 8 percent.
I have lost the link to the first but the link to the second research paper is attached.
So instead of 10% let's settle for 6 or 7%, based on science.
This post shows a very limited understanding of weights and dynamics. Perhaps you could explain why huge semi-trailers in Canada, for example, have NO front brakes? You may get away with 6%-7% towball weight on shorter, lightweight caravans behind heavier cars, but not with a "typical" Australian van behind a lightweight twin-cab or such. You can't simply decide you'll defy the simple laws of physics.Cheers
Jobarr, I take it you didn't read the paper.
You talk about weight when the M in ATM and GVM stands for mass, not weight.
Are you saying that all, repeat all, semi-trailers in Canada are not fitted with front brakes.
According to Transport Canada They are required to have brakes.
I assume that semi-trailers are covered by the attached document, if not Yobarr, maybe you could provide the Transport Canada document which covers semi-trailers and show that they do not need brakes on their front wheels.
Yes, I agree that the vehicle design does have most braking on the front wheels. But having the van brakes doing practically nothing is not the best strategy.
The best would be for each axle to contribute an equal percentage of it's braking capability (based on grip on the road), so that all wheels shared the task. In the case of an emergency stop it would be pretty silly to have the tow vehicle skidding (or ABS activating) while the van brakes are just loafing along. Not having that additional braking capacity could mean the difference between stopping in time, or 5 metres after you hit something.
Or, as you round a bend there is water on the road. With most of the braking on the tow vehicle front wheels they are much more likely to lock up. With the braking shared across all wheels, less likely.
But all this misses the point I was making about reserving the best brakes in case they are really needed. 60 years ago we didn't have the ability to control the van braking with a knob on the dashboard. Now that we do, why not use it?
I'm not going to respond to the 10% towball issue as there has been plenty of discussion on that.
-- Edited by Are We Lost on Friday 16th of September 2022 11:04:04 PM
Well that says it all, you know better than the manufacturer. What arrogance?
For your information Jobarr, my caravan is a dual axle torsion bar suspension system.
Increasing tow-ball weight moves the van centre of gravity towards the front of the van.
Weight is moved off the back wheels and onto the front wheels when the tow-ball weight is increased.
Increase the tow-ball weight too much and the load on the front tyres could exceed the tyres rating.
Which is not something we want to do.
So I will be ignoring your erroneous advice and heeding the caravan manufacturer.
And I have read the study that you have posted jegog.
I will make some points as to why in my opinion, yobarr is correct.
1. The tow ball mass as shown on your compliance plate as given by the manufacturer refers to the tow ball down load in an unladen state, and so is as useless as tits on a bull with regards the vans final weights fully laden and the rigs final stability..
The manufacturer has no real idea of the final tow ball weight other than the laden TBW should be roughly within a range and that, in this country, is recommended to be between 8% and 12%.
This percentage has been arrived at by various vehicle engineers and licensing authorities in this country as a target TBW.
Remember that the study in question was done in Britain with very light trailer mass and being towed by light cars with very light rear axle loadings, so for their common conditions, this study makes sense. They recommend a TBW of 6 to 8% which for the very light van in question is going to be somewhere about right
2. Australian vans are generally larger and much heavier than their European counterparts and are normally towed with 4WD vehicles that have greater mass and higher axle loads plus suspension much better suited to towing, so having the van load slightly nose heavy is a good thing.
It increases van stability and although it places slightly more load on the vans front wheels, if you check the weights on the axle groups on a well balanced rig, it is not enough to be of any concern.
The target of 10% TBW is a reasonable figure to aim for to maintain good stability.
The much heavier vans we see in this country have much greater yaw enertia than the light Euro vans.
3.A van which has its axle group positioned rearward of the centreline will inevitably produce a more stable rig as this increases the distance from the tow hitch. The study confirms that.
This however will also increase the TBW and it will tend to move the C of G forwards which is where you want it.
In all the vans, trailers and horse floats I have towed about the country, having the loaded weight giving a slightly forward C of G has always resulted in a good towing and stable rig, regardless of the suspension system employed.
4. If you are concerned that a target TBW of 10% might unload the front wheels of the tow tugs then that's where the good old WDH comes in to fine tune the handling and braking.