Eaglemax wrote:

---

My assertion that the 10% rule of ATM to towball weight is so variable that it is a starting point only for the average caravanner. TBW isnt a mandatory requirement, it can be a recommendation.

Most people realise that there is various ways to increase yaw like speed, low or high towball weight etc. I suggest that nearly every rig is unique. This is no more apparent to other countries unwritten rule? like USA at 12 to 15% and England as low as 4% but commonly 5-7%

https://www.startrescue.co.uk/breakdown-cover/motoring-advice/safety-and-security/how-to-tow-a-caravan-complete-guide  

 

extract of above-  

"What is a caravans nose weight?

Your caravan's nose weight is the downward force of its coupling head on your cars tow ball. Generally, for towing stability this should be 5-7% of your caravan's laden weight.

Other terms for MAM are Maximum Permissible Weight (MPW) or Gross Vehicle Weight (GVW).

To meet legal requirements, the car and caravan's combined actual laden weight must not exceed the Gross Train Weight (GTW) the maximum allowed combined weight of car and caravan, as specified by the car manufacturer."

 

Some in the UK suggest 4% to be the lowest. Road conditions might well be far different in these 3 countries but thats imo irrelevant. If 5% is considered safe in Uk how is 5% on our roads going to cause a rollover?

Im going to suggest that caravan rigs could go as low as 5% when the caravan GTM is under 2000kg.  Provisos could include - the tow vehicle is heavier than the caravan and- friction hitch and ESC is installed etc.

 

If anyone can tell me of any major differences from roads in the UK to roads in Australia that more prevent sway in the UK I'm all ears. Isnt a road a road?

 

RV books by Collyn Rivers can do a lot to help those who actually WANT to learn from a recognised expert who has over 60 years experience in physics, dynamics and vehicle design. The books will not help those who, deep down, know that their  setup is unsafe, but desperately seek reassurance that all is good.

Yanks can go to 15% because their towing usually is done by Goddamn Pickup Trucks with HUGE GVMs and rear axle carrying capacities compared with Australia's cars, particularly the popular twin-cabs and other light weights.

Who cares if you've got 500kg towball weight on a truck with a GVM of 7 ton and rear axle capacity of 4000kg, or whatever it may be?

And, most importantly, the truck weighs heaps more than the van, so we get none of this "Tail wagging the Dog" which is rife in Oz.

Poms generally have feather-weight vans towed at low speeds by smallish cars that could never cope with 10% towball weight.

Get on the internet and have a bit of a look at the number of written-off cars and vans over there.

Nowhere have I ever seen it written that towball weight must be 10%, with the usual suggestion being that the "generally accepted towball weight is around 10%".  This figure is dictated by common sense and simple physics, 

The most important thing to remember is that if safety is of any concern always the weight on the wheels of the car must be at least 10% more than the weight on the wheels of the van. Simple physics.Cheers

 

-- Edited by Webmaster on Monday 21st of August 2023 10:51:03 AM

yobarr wrote:

---

Eaglemax wrote:

---

My assertion that the 10% rule of ATM to towball weight is so variable that it is a starting point only for the average caravanner. TBW isnt a mandatory requirement, it can be a recommendation.

Most people realise that there is various ways to increase yaw like speed, low or high towball weight etc. I suggest that nearly every rig is unique. This is no more apparent to other countries unwritten rule? like USA at 12 to 15% and England as low as 4% but commonly 5-7%

https://www.startrescue.co.uk/breakdown-cover/motoring-advice/safety-and-security/how-to-tow-a-caravan-complete-guide  

 

extract of above-  

"What is a caravans nose weight?

Your caravan's nose weight is the downward force of its coupling head on your cars tow ball. Generally, for towing stability this should be 5-7% of your caravan's laden weight.

Other terms for MAM are Maximum Permissible Weight (MPW) or Gross Vehicle Weight (GVW).

To meet legal requirements, the car and caravan's combined actual laden weight must not exceed the Gross Train Weight (GTW) the maximum allowed combined weight of car and caravan, as specified by the car manufacturer."

 

Some in the UK suggest 4% to be the lowest. Road conditions might well be far different in these 3 countries but thats imo irrelevant. If 5% is considered safe in Uk how is 5% on our roads going to cause a rollover?

Im going to suggest that caravan rigs could go as low as 5% when the caravan GTM is under 2000kg.  Provisos could include - the tow vehicle is heavier than the caravan and- friction hitch and ESC is installed etc.

 

If anyone can tell me of any major differences from roads in the UK to roads in Australia that more prevent sway in the UK I'm all ears. Isnt a road a road?

---

 First up I'll say that this post is bound to cause even more confusion  for those already struggling to understand weights and simple physics. Much of the similar rubbish posted by members who no doubt have good intentions doesn't help.

RV books by Collyn Rivers can do a lot to help those who actually WANT to learn from a recognised expert who has over 60 years experience in physics, dynamics and vehicle design. The books will not help those who, deep down, know that their  setup is unsafe, but desperately seek reassurance that all is good.

Can't be bothered covering the basics again, as I know that you are more than familiar with them, so I wonder what the point of this post is?

Yanks can go to 15% because their towing usually is done by Goddamn Pickup Trucks with HUGE GVMs and rear axle carrying capacities compared with Australia's cars, particularly the popular twin-cabs and other light weights.

Who cares if you've got 500kg towball weight on a truck with a GVM of 7 ton and rear axle capacity of 4000kg, or whatever it may be?

And, most importantly, the truck weighs heaps more than the van, so we get none of this "Tail wagging the Dog" which is rife in Oz.

Poms generally have feather-weight vans towed at low speeds by smallish cars that could never cope with 10% towball weight.

Get on the internet and have a bit of a look at the number of written-off cars and vans over there.

Nowhere have I ever seen it written that towball weight must be 10%, with the usual suggestion being that the "generally accepted towball weight is around 10%".  This figure is dictated by common sense and simple physics, and no matter how much you may waffle-on, these things will never change.

Over the last 5 years or so I have made many detailed posts on this topic, but again I will say that I simply can't be bothered explaining again. All your post does is create confusion for those trying to learn.

The most important thing to remember is that if safety is of any concern always the weight on the wheels of the car must be at least 10% more than the weight on the wheels of the van. Simple physics.Cheers

 

---

 

My apologies Yobarr, I was unaware you are now admin of this section whereby you determine who can ask questions and who cannot. I'm also sorry you rcant be bothered answering , so much so that your took the bother to answer. Perhaps I could remind you of that famous saying

 

I Disapprove of What You Say, But I Will Defend to the Death Your Right to Say It

 

The point of the post is in my last sentence and in the topic heading. If you cant see that then its simple English not unlike your "simple physics. As your reply borders on abuse and you have nothing substantial to say in terms of the differences in UK/Aussie roads I gather you wont be further contributing. I am not responsible for other caravanners confusion on weights.

I now realise why you are banned from another forum. Cheers.

-- Edited by Eaglemax on Saturday 19th of August 2023 06:40:54 PM

-- Edited by Eaglemax on Saturday 19th of August 2023 06:43:26 PM

Are We Lost wrote:

---

Speed limits would be a pretty big factor. Mainly 80kph on single carriageway highways.

UK Towing speed

Also, from the link you posted, only those licensed before 1997 are authorised to tow the typical van size here without getting a specific licence.

So, apart from the slower speeds, for someone with "only" 25 years driving experience they are limited to:

• Maximum of 3500kg GCM (total weight of car and van) AND

• ATM of less than the UNLADEN weight of the tow vehicle .... and note it is ATM, not actual van weight.

That is a huge difference in requirements. With my Ford Ranger, generally considered safe to tow up around 3000kg, a driver licensed after 1997 would need that licence upgrade to tow more than 2200kg.

---

Thanks Stephen, Great to see that even Poms have enough brains to understand that the tow vehicle MUST be heavier than the van if safety is of any concern.

They take it even further though by saying that ATM is the figure to be used, as opposed to Australia where ACTUAL weight is the figure applicable.

Not having seen these rules before I now find it easy to understand why their caravans are featherweight.

Seems though that they too use the ability to pull a DOG trailer in their tow ratings. Stupidity. Cheers

So, 6% towball weight is fine in Australia if you don't exceed 105kph. Tow ball percentage is not a legal requirement. See link. https://outbacktravelaustralia.com.au/driving-towing-towing/towball-weight-and-trailer-stability/

Yeh, focus is on towball weight to ATM %. Unfortunately most caravanners including forums focus on heavy vans and 10% is a starting point albeit non binary. Such percentage you'll never get a fine for even 1%. The differences between countries of this percentage is mammoth. 4-7% in UK, 10% here, 10-15% USA. UK has lightweight vans but Australia also imports them and has built them (eg Jurgens). So the question is - if you tow a lightweight van here why wouldn't you seek 4-7% percentage? Eg 1.van atm 1500kg tbw 150kg. That's ok. 2. Van atm 600kg tbw 30kg or 5%. No reason you wouldn't. In fact I towed a home made van around Oz in 2016 atm 748kg, tbw 30kg 4%, without any issues. Apart from speed I can't find one other reason for lighter vans to go to 10% but rather than some that attempt to shut me down from free speech I'm genuinely interested in reasons why you shouldn't go down to 5% on a light van say under 2000kg ATM . If I don't get replies that's ok, then there's no valid reasons. Thanks.

. Thanks.

-- Edited by Eaglemax on Sunday 20th of August 2023 05:29:31 PM

Are We Lost wrote:

---

Even with the recent relaxation of towing licensing in UK, you miss the point of the comparison. Drive at low speed and you can get away with just about any configuration. Up to 80kph the likelihood of the van starting to sway is vastly lower than the typical speeds that sway induced accidents happen here. Secondly, having a van weighing a lot less than the tow vehicle will have a similar effect. And then the third factor is the popularity of lighter weight vans there. Then for years drivers had to be tested to get their towing approval.

With all of those improvements in safety in the UK it means there is negligible risk of sway developing, and thus a lower ball weight percentage can be tolerated.

-- Edited by Are We Lost on Sunday 20th of August 2023 05:19:37 PM

---

 Thankyou for replying.  Re: "Up to 80kph the likelihood of the van starting to sway is vastly lower than the typical speeds that sway induced accidents happen here." Yes, agree, so I cant see why a stepped percentage is not thought of. A blanket 10% (which isnt a law) cant and should not be applied to all rigs in Oz. Eg 4% under 700kg  6% under 1500kg and so on. I gather the reason is big heavy vans make up the majority and that would firm my point that lightweight vans are on a lower level of danger with their TBW to ATM percentage.  Heavier tow vehicle to van ratio also is significant but seeing as we are dealing with a non official "rule of thumb" that would be hard to add to that. Popularity isnt in the equation imo. Driver testing? What would they learn that would still allow a rule of thumb at 4%?. You've brought up a number of possibly valid reasons Steve but I suppose I'm looking for that Trump card that squashes all. 

 

Lightweight vans are a different ball game. I mean a van like I built at 748kg ATM didnt even need brakes. How many garden trailer owners weigh their 6x4 box trailer towball weight when filled with sand? One load of dry sand can weigh 500kg, the next load could be wetter and weigh 700kg and have a negative ball weight but in all honesty how many would go via a weigh station and weight it? None!

 

A few examples-

 

Euro Hobyy ATM 900kg  towball weight 45kg  TBW at 5%

PMX campers Winton 10 ATM 1500kg  Towball weight 70kg equals less than 5%

Adria Action ATM 1400kg  Towball weight less than 100kg or 7%

Avan Aliner d ATM 1185 towball weight 65kg = 6%

 

Hence the 10% rule which is a rule of thumb only, doesnt apply to lightweight vans or the above manufacturers are dangerous van makers. The 4 examples is common not cherry picked.  

-- Edited by Eaglemax on Sunday 20th of August 2023 06:03:12 PM

A very interesting conversation. One must also look at the tow vehicle limitations. My Patrol has a maximum tow weight of 3200 kilogrammes, but a maximum tow ball load of 200 kilos. I think that this shows that even the vehicle manufacturer does not think that 10 per cent is important.
Imagine, a 3200 kilo van behind a car at 3000 kilo GVM and 200 0nj the ball. No thanks!

Ben.

Greg 1 wrote:

---

Are those TB figures you have quoted there Eaglemax the actual loaded TB at full ATM or just the figure that the manufacturer stamps on the compliance plate which is the TB at Tare? There is a considerable difference. For agreements sake the TB of my van at Tare is 180kgs, but fully loaded at ATM is 308kgs which is just a smidge over the 10%. A very lightweight van can get away with less than the 10%. What yobarr is saying is true. But a 3 tonne van is going to move the tow vehicle around with a light TB load simply due to the shear bulk of the van.

---

 "Considerable difference" Yes, like most or all caravans the listed towball weight is at tare. But if I purchased any of those 4 vans/campers listed as the towball percentage isnt a law I could load those vans and leave the percentage as it is, no problem, especially as you mentioned the lighter the caravan "can get away with less than 10%"... which is one of my points of evidence of NOT sticking to the 10% rule for lighter vans which some knee jerk whenever the topic is raised sprouting "simple physics". Furthermore the debate isnt about yank tanks etc but of 2 things- that such low ball weight is acceptable eg 5%+ for lightweight vans and 2/ that Australia has road conditions like most places in the world so why do people staunchly stick to 10% as a blanket "fixes all" formula?

If manufacturers or Authorities believed that the percentage at tare eg 5% was safer going to 10% when loaded surely safety would determine it be legislated? Road traffic inspections would make it an easy addition to measure such percentage. To add to that percentage ATM to tBW is not even legally bound in heavy vans- struth!!! So, a van ATM 3000kg could have a TBW of 150kg and be legal at 5%.  That's where "simple physics" takes hold more so than a 1000kg ATM caravan. For the sake of side issues we assume the tow vehicle is always heavier than the van. 

Eaglemax wrote:

---

Ben Taxyl wrote:

---

A very interesting conversation. One must also look at the tow vehicle limitations. My Patrol has a maximum tow weight of 3200 kilogrammes, but a maximum tow ball load of 200 kilos. I think that this shows that even the vehicle manufacturer does not think that 10 per cent is important.
Imagine, a 3200 kilo van behind a car at 3000 kilo GVM and 200 0nj the ball. No thanks!

Ben.

---

 Thanks Ben for your reply of which you have a right to print and its encouraged and I'm glad you find it interesting .

. As per my last reply to Greg heavier vans are very different to lightweight vans and the caravan world is fixated on heavy vans and do not cater for situations with light vans which is clear in this thread with the stubbornness of Yobarr that resorts to "simple physics" as his fortress of evidence or referal to Colin Rivers as his idol but nothing arrives to concrete evidence of less than 10% is more ok for lightweight vans. It is indeed "simple physics" that a van weighing 1000kg doesnt need 100kg on the ball but your rig is far different. I'll leave your rig to Yobarr as that is where his knowledge lies- heavy van rigs but isnt interested in good sound debate on lightweight vans where he knows nothing. Intimidation is his nature

---

 Perhaps you could kindly explain how my "simple physics" confuses you, at the same time letting Collyn Rivers know that he too is mistaken with the detailed information in his many books. Collyn is recognised world-wide as an expert in weights, dynamics and vehicle design, with over 60 years experience in this field.
Not only are you now back-pedalling with your claims, you at least seem to understand that, if safety is of any concern, always the weight on the wheels of the car must be at least 10% greater than the weight on the wheels of the van.

And once again I will say 10% is the generally accepted towball weight for safe towing. As far as I can recall,NEVER have I said that towball weight MUST be 10%, and never have I stooped to analysing a fellow forum members nature, let alone getting that analysis wrong. Have a great day. Cheers

You're waffling on Yobarr.

yobarr wrote:

---

Ben Taxyl wrote:

---

A very interesting conversation. One must also look at the tow vehicle limitations. My Patrol has a maximum tow weight of 3200 kilogrammes, but a maximum tow ball load of 200 kilos. I think that this shows that even the vehicle manufacturer does not think that 10 per cent is important.
Imagine, a 3200 kilo van behind a car at 3000 kilo GVM and 200 0nj the ball. No thanks!

Ben.

---

 Hi Ben. You seem totally confused so I would strongly suggest that you use the "Search" function to find explanations of how tow ratings are issued. 
 Failing that, do a bit of research. 
However, as with a Pajero, using factory tow ratings with your car when towing a 3200Kg PIG trailer means that you are an accident looking for a place to happen. Cheers

P.S Is your car one of those 3 litre models?

-- Edited by yobarr on Monday 21st of August 2023 10:38:21 AM

---

 Tobarr,

I don't know why you think I am confused about my vehicle. Yes, it is a 3litre Patrol and the sticker on the rear door clearly states that the maximum towball download is 200 kilogrammes and the maximum towed weight is 3200 kilogrammes.  Where is the alleged confusion? My original post was about the 10 per cent rule not being acknowledged by vehicle manufacturers.

Cheers, Ben.

 

Are We Lost wrote:

---

Ben Taxyl wrote:

---

My original post was about the 10 per cent rule not being acknowledged by vehicle manufacturers.

---

 Some do. This snippet is from my 2018 Ford Ranger owners' manual.

So the design engineers for one of the more capable tow vehicles in that market believe that less than 10% is unsafe. I know it's a "one size fits all" situation, which is not ideal, but I assume that is because it keeps things simple.

---

 Thanks Stephen, for posting this. Had Ben taken my advice to research how tow ratings are issued he may not be as confused as he appears to be.

I did not say that he is confused about his vehicle, as the figures are as he posted, but the fact that max towball weight is listed as 200kg DOES NOT mean that that vehicle has ANY chance of safely towing 3200kg as a PIG trailer.
We can only help those who are receptive to being helped. Cheers.

Are We Lost wrote:

---

Ben Taxyl wrote:

---

My original post was about the 10 per cent rule not being acknowledged by vehicle manufacturers.

---

 Some do. This snippet is from my 2018 Ford Ranger owners' manual.

So the design engineers for one of the more capable tow vehicles in that market believe that less than 10% is unsafe. I know it's a "one size fits all" situation, which is not ideal, but I assume that is because it keeps things simple.

 

---

 It's less than ideal. You cant compare every tow vehicle to one model from one manufacturer towing any caravan. Sorry mate, its cherry picking. 

In Albury and other places ex UK caravans are sold, ther eis many in Australia that have light towball weights but if the towball weights were unsafe they would require the need for stickers like that one you posted. No Government agency has decided to place such stickers on imported caravans to my knowledge. Doesnt that tell you something AWL?