Is this common issue, or is this a problem ?

RobDor · Veteran Member

Is this common issue, or is this a problem ?

Radar · Guru

RobDor wrote:
Just setting up and planning for first trip. Tech details as follows, van tare 2200, atm 2600, axle group 2600, tow ball (on plate) 210 (not sure how they come up with that ! ). My GCM with BT50 is 5950 , so Im well within limits there. I have 2 X 127 litre water tanks in van, so I filled both, also filled 15 litre toilet flush and added about 50 kgs of other things to simulate trip - no food and no clothes etc packed yet. Took it to weigh bridge yesterday so I know what Im dealing with and they measured van at 2680 ! 80 kgs over, so hell knows where thats coming from ?? Worse thing is they said ball weight was 320..what the ? The GCM was 5200 so thats not an issue. Is this a common issue ? Do I need to empty one of the tanks when travelling ? Do I need to upgrade van ATM ? But, that may cost heaps. Seems a bit silly that ATM wont cater for full tanks and some load. The car by the way had full fuel and myself and the mrs in there. Heres a pic of van plate and weigh bridge ticket. Im not sure I trust these figures, might try another weigh bridge. Any advice appreciated. Thanks

yes, a general problem with caravans.

A couple of things I would look at as I don't think up grading the "vin plate is the way to go", the caravan is already a heavy load on a single axle.

1. Travel with 1 tank full until you are close to your extented camp site and learn to manage your water.

2. Re plumb the toilet flush water from the main tank.

We were about 100kg over on our first outing, the caravan manufacture agreed being a duel axle rewrote the VIN plate without any modifications but we are still very careful about adding weight.

We can go along way with our 2 water tanks of 140 litres with a mix of low cost and freedom camps.

Maybe as I did, look at how much battery you carrying as they are around 34kgs each, we went from 180amps to 110amps, coming upto 12 months now and never been a issue with power but I do live in Queensland.

Hope this gives you some ideas.

yobarr · Guru

RobDor wrote:
Just setting up and planning for first trip. Tech details as follows, van tare 2200, atm 2600, axle group 2600, tow ball (on plate) 210 (not sure how they come up with that ! ). My GCM with BT50 is 5950 , so Im well within limits there. I have 2 X 127 litre water tanks in van, so I filled both, also filled 15 litre toilet flush and added about 50 kgs of other things to simulate trip - no food and no clothes etc packed yet. Took it to weigh bridge yesterday so I know what Im dealing with and they measured van at 2680 ! 80 kgs over, so hell knows where thats coming from ?? Worse thing is they said ball weight was 320..what the ? The GCM was 5200 so thats not an issue. Is this a common issue ? Do I need to empty one of the tanks when travelling ? Do I need to upgrade van ATM ? But, that may cost heaps. Seems a bit silly that ATM wont cater for full tanks and some load. The car by the way had full fuel and myself and the mrs in there. Heres a pic of van plate and weigh bridge ticket. Im not sure I trust these figures, might try another weigh bridge. Any advice appreciated. Thanks

Hi Rob. Today I'm a bit busy felling trees,but later I will post something.How the vehicles are weighed has an influence on weights,which should be taken in the centre of the weighbridge,rather than at the ends.There was over 200kg difference when I split the car and van,and "yes",it was a registered weighbridge at a metal supply yard.How were weights done? With van attached,did you weigh front axle of car,then both axles? This gives you loaded rear axle weight and total weight of car. (GVM if you like). Next,you need to drop caravan onto weighbridge,supported by jockey wheel, and drive car off bridge.Take weight.(ATM if you like).Now reconnect van to car,and drive forward until car is just off bridge,and take weight on van wheels.(GTM).You now can calculate towball weight,but this is highly inaccurate,given that weighbridges generally have 20kg increments.At first glance,it seems you need more weight in car,but the rear axle load may be the stumbling point,as from memory,it is inly 1850kg.The new Isuzu BT50 has a 1910kg rear axle.If your towball weight is indeed 320kg,which I doubt,obviously your GTM is 2360kg.Towball weight on plate means exactly NOTHING.If you could tell how weights were done,that would help.Experience tells me that many weighbridge operators have no clue! Cheers

-- Edited by yobarr on Sunday 11th of July 2021 09:55:02 AM

Gundog · Guru

Hi Rob,

Gee mate your doing all the right things before you head off, but you have been caught with the old tare chestnut, the tare is the weight of the van as it leaves the factory with no accessories fitted like gas bottles etc, some of these can chew over 100kg off your available load availability, just filling your water tanks takes another 250 kg thus leaving you with almost no load available.

The solution is not easy but it requires some creative thinking, look for any item that can be stored in the tub of the ute, like one gas bottle, spare wheel etc and half fill one water tank, and topping up daily or as the need arises.

An ATM upgrade could become an expensive exercise, because the ATM and Axle Group are both rated at 2600, the axle group would have to be upgraded before the ATM could be considered, things like brakes, tyres etc can be expensive, perhaps a call to Cruisemaster could give you better infomation.

All the best searching a solution is not always easy.

yobarr · Guru

Gundog wrote:
Hi Rob,
Gee mate your doing all the right things before you head off, but you have been caught with the old tare chestnut, the tare is the weight of the van as it leaves the factory with no accessories fitted like gas bottles etc, some of these can chew over 100kg off your available load availability, just filling your water tanks takes another 250 kg thus leaving you with almost no load available.
The solution is not easy but it requires some creative thinking, look for any item that can be stored in the tub of the ute, like one gas bottle, spare wheel etc and half fill one water tank, and topping up daily or as the need arises.
An ATM upgrade could become an expensive exercise, because the ATM and axle group are both rated at 2600kg,the axle group would have to be upgraded before the ATM could be considered, things like brakes, tyres etc can be expensive, perhaps a call to Cruisemaster could give you better infomation.
All the best searching a solution is not always easy.

Hi Graham.In your post above,I have highlighted what is incorrect.As you no doubt are aware,ATM is made up of allowable weight on wheels plus towball weight.Cheers.

RobDor · Veteran Member

yobarr wrote:
RobDor wrote:
Just setting up and planning for first trip. Tech details as follows, van tare 2200, atm 2600, axle group 2600, tow ball (on plate) 210 (not sure how they come up with that ! ). My GCM with BT50 is 5950 , so Im well within limits there. I have 2 X 127 litre water tanks in van, so I filled both, also filled 15 litre toilet flush and added about 50 kgs of other things to simulate trip - no food and no clothes etc packed yet. Took it to weigh bridge yesterday so I know what Im dealing with and they measured van at 2680 ! 80 kgs over, so hell knows where thats coming from ?? Worse thing is they said ball weight was 320..what the ? The GCM was 5200 so thats not an issue. Is this a common issue ? Do I need to empty one of the tanks when travelling ? Do I need to upgrade van ATM ? But, that may cost heaps. Seems a bit silly that ATM wont cater for full tanks and some load. The car by the way had full fuel and myself and the mrs in there. Heres a pic of van plate and weigh bridge ticket. Im not sure I trust these figures, might try another weigh bridge. Any advice appreciated. Thanks
Hi Rob. Today I'm a bit busy felling trees,but later I will post something.How the vehicles are weighed has an influence on weights,which should be taken in the centre of the weighbridge,rather than at the ends.There was over 200kg difference when I split the car and van,and "yes",it was a registered weighbridge at a metal supply yard.How were weights done? With van attached,did you weigh front axle of car,then both axles? This gives you loaded rear axle weight and total weight of car. (GVM if you like). Next,you need to drop caravan onto weighbridge,supported by jockey wheel, and drive car off bridge.Take weight.(ATM if you like).Now reconnect van to car,and drive forward until car is just off bridge,and take weight on van wheels.(GTM).You now can calculate towball weight,but this is highly inaccurate,given that weighbridges generally have 20kg increments.At first glance,it seems you need more weight in car,but the rear axle load may be the stumbling point,as from memory,it is inly 1850kg.The new Isuzu BT50 has a 1910kg rear axle.If your towball weight is indeed 320kg,which I doubt,obviously your GTM is 2360kg.Towball weight on plate means exactly NOTHING.If you could tell how weights were done,that would help.Experience tells me that many weighbridge operators have no clue! Cheers

-- Edited by yobarr on Sunday 11th of July 2021 09:55:02 AM

Yes, I agree with that last sentence, I felt he had no clue and Im no expert. I will be going to another weighbridge to compare. Most of the weighing was at the ends of weighbridge. First weigh was drive on fully hitched and stop with just car on - 2.84T , drive further along, so that van is now just on weighbridge - 5.2 T, drive along so car is just off weighbridge and weigh van still hitched - 2.36 T, leave same spot and leave everything connected and just jockey wheel off the hitch, so its clear of car - 2.68 T. Cheers

RobDor · Veteran Member

yobarr wrote:
Gundog wrote:
Hi Rob,
Gee mate your doing all the right things before you head off, but you have been caught with the old tare chestnut, the tare is the weight of the van as it leaves the factory with no accessories fitted like gas bottles etc, some of these can chew over 100kg off your available load availability, just filling your water tanks takes another 250 kg thus leaving you with almost no load available.
The solution is not easy but it requires some creative thinking, look for any item that can be stored in the tub of the ute, like one gas bottle, spare wheel etc and half fill one water tank, and topping up daily or as the need arises.
An ATM upgrade could become an expensive exercise, because the ATM and axle group are both rated at 2600kg,the axle group would have to be upgraded before the ATM could be considered, things like brakes, tyres etc can be expensive, perhaps a call to Cruisemaster could give you better infomation.
All the best searching a solution is not always easy.
Hi Graham.In your post above,I have highlighted what is incorrect.As you no doubt are aware,ATM is made up of allowable weight on wheels plus towball weight.Cheers.

I thought ATM is all up weight of Van, which includes the towball weight ?

Gundog · Guru

my statement which you have highlighted is correct according to the id plate. Yes I understand the ATM is all up weight no connected to tow vehiclw

As axle group and ATM are both rated at 2600kg, then the axle group need to be rerated befor the ATM can be increased.

id plate.jpg

Are We Lost · Guru

From my reading, the Axle Group is capable of supporting 2600kg in addition to the towball load. However, Millard has used that same figure for ATM.

The towball mass is what it weighed ex factory, and they have used that (virtually meaningless figure) to determine the GTM (ATM 2600 - Towball 210 = 2390 GTM). But the GTM is a rating, and as per below must not be exceeded. I presume 2390kg is what appears on your registration papers.

Road Safety NSW - weights explained

Gross Trailer Mass (GTM) is the maximum mass recommeded by the manufacturer of your fully loaded caravan when it is hitched to your tow vehicle. The GTM of the caravan is transmitted to the ground by only the caravan tyres and excludes the mass distributed to the towing vehicle through the coupling. The GTM of your caravan can be found on the vehicle plate or in the manufacturer's handbook and must not be exceeded. To measure your GTM, weigh your loaded caravan when it is attached to your towing vehicle, and make sure your measured mass does not exceed your specified GTM capacity.

So, it should be fairly easy to get an engineer to upgrade your ratings to a GTM of 2600kg, with commensurate increase in ATM. Note (in NSW) that over around 2500kg the annual registration fee jumps up a bit.

-- Edited by Are We Lost on Sunday 11th of July 2021 01:47:39 PM

yobarr · Guru

Gundog wrote:
my statement which you have highlighted is correct according to the id plate. Yes I understand the ATM is all up weight no connected to tow vehiclw
As axle group and ATM are both rated at 2600kg, then the axle group need to be rerated befor the ATM can be increased.

Later I will explain,but axle weight does not need to be rerated as it is currently greater than GTM,.Cheers

RobDor · Veteran Member

Are We Lost wrote:
From my reading, the Axle Group is capable of supporting 2600kg in addition to the towball load. However, Millard has used that same figure for ATM.
The towball mass is what it weighed ex factory, and they have used that (virtually meaningless figure) to determine the GTM (ATM 2600 - Towball 210 = 2390 GTM). But the GTM is a rating, and as per below must not be exceeded. I presume 2390kg is what appears on your registration papers.
Road Safety NSW - weights explained

Gross Trailer Mass (GTM) is the maximum mass recommeded by the manufacturer of your fully loaded caravan when it is hitched to your tow vehicle. The GTM of the caravan is transmitted to the ground by only the caravan tyres and excludes the mass distributed to the towing vehicle through the coupling. The GTM of your caravan can be found on the vehicle plate or in the manufacturer's handbook and must not be exceeded. To measure your GTM, weigh your loaded caravan when it is attached to your towing vehicle, and make sure your measured mass does not exceed your specified GTM capacity.

So, it should be fairly easy to get an engineer to upgrade your ratings to a GTM of 2600kg, with commensurate increase in ATM. Note (in NSW) that over around 2500kg the annual registration fee jumps up a bit.

-- Edited by Are We Lost on Sunday 11th of July 2021 01:47:39 PM

My rego papers say tare of 2200 and atm of 2600. So, from what youre saying, the atm should be more like 2800 ?

RobDor · Veteran Member

yobarr wrote:
Gundog wrote:
my statement which you have highlighted is correct according to the id plate. Yes I understand the ATM is all up weight no connected to tow vehiclw
As axle group and ATM are both rated at 2600kg, then the axle group need to be rerated befor the ATM can be increased.

Later I will explain,but axle weight does not need to be rerated as it is currently greater than GTM,.Cheers

So, based on that, if the GTM was 2600, that would be ok, because it matches the axle group rating ? So, could the ATM be increased by 200 kgs ? That would make more sense. Thanks

yobarr · Guru

Are We Lost wrote:
From my reading, the Axle Group is capable of supporting 2600kg in addition to the towball load. However, Millard has used that same figure for ATM.
The towball mass is what it weighed ex factory, and they have used that (virtually meaningless figure) to determine the GTM (ATM 2600 - Towball 210 = 2390 GTM). But the GTM is a rating, and as per below must not be exceeded. I presume 2390kg is what appears on your registration papers.
Road Safety NSW - weights explained

Gross Trailer Mass (GTM) is the maximum mass recommeded by the manufacturer of your fully loaded caravan when it is hitched to your tow vehicle. The GTM of the caravan is transmitted to the ground by only the caravan tyres and excludes the mass distributed to the towing vehicle through the coupling. The GTM of your caravan can be found on the vehicle plate or in the manufacturer's handbook and must not be exceeded. To measure your GTM, weigh your loaded caravan when it is attached to your towing vehicle, and make sure your measured mass does not exceed your specified GTM capacity.
So, it should be fairly easy to get an engineer to upgrade your ratings to a GTM of 2600kg, with commensurate increase in ATM. Note (in NSW) that over around 2500kg the annual registration fee jumps up a bit.
-- Edited by Are We Lost on Sunday 11th of July 2021 01:47:39 PM

Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM

RobDor · Veteran Member

yobarr wrote:

Are We Lost wrote:
From my reading, the Axle Group is capable of supporting 2600kg in addition to the towball load. However, Millard has used that same figure for ATM.
The towball mass is what it weighed ex factory, and they have used that (virtually meaningless figure) to determine the GTM (ATM 2600 - Towball 210 = 2390 GTM). But the GTM is a rating, and as per below must not be exceeded. I presume 2390kg is what appears on your registration papers.
Road Safety NSW - weights explained

Gross Trailer Mass (GTM) is the maximum mass recommeded by the manufacturer of your fully loaded caravan when it is hitched to your tow vehicle. The GTM of the caravan is transmitted to the ground by only the caravan tyres and excludes the mass distributed to the towing vehicle through the coupling. The GTM of your caravan can be found on the vehicle plate or in the manufacturer's handbook and must not be exceeded. To measure your GTM, weigh your loaded caravan when it is attached to your towing vehicle, and make sure your measured mass does not exceed your specified GTM capacity.
So, it should be fairly easy to get an engineer to upgrade your ratings to a GTM of 2600kg, with commensurate increase in ATM. Note (in NSW) that over around 2500kg the annual registration fee jumps up a bit.
-- Edited by Are We Lost on Sunday 11th of July 2021 01:47:39 PM
Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM

Ok, thanks for the advice fellas. Sounds like I should get on to a trailer/van engineer, atm changer type person (not sure what theyre called) and see if I can get GVM/ATM increased to reasonable level. FYI , the van already has 12 inch brakes. Although, im not sure what the limit is with single axle trailers, maybe theres a limit there ?

yobarr · Guru

Rob,just Google "Engineering Consultants,Cairns" and you will get a list of engineers.If the one you select is unable to help you,it is likely that he will be able to point you in the right direction.We would be interested to hear how you fare,as the information you provide may help others understand the process ! Cheers

RobDor · Veteran Member

yobarr wrote:

Are We Lost wrote:
From my reading, the Axle Group is capable of supporting 2600kg in addition to the towball load. However, Millard has used that same figure for ATM.
The towball mass is what it weighed ex factory, and they have used that (virtually meaningless figure) to determine the GTM (ATM 2600 - Towball 210 = 2390 GTM). But the GTM is a rating, and as per below must not be exceeded. I presume 2390kg is what appears on your registration papers.
Road Safety NSW - weights explained

Gross Trailer Mass (GTM) is the maximum mass recommeded by the manufacturer of your fully loaded caravan when it is hitched to your tow vehicle. The GTM of the caravan is transmitted to the ground by only the caravan tyres and excludes the mass distributed to the towing vehicle through the coupling. The GTM of your caravan can be found on the vehicle plate or in the manufacturer's handbook and must not be exceeded. To measure your GTM, weigh your loaded caravan when it is attached to your towing vehicle, and make sure your measured mass does not exceed your specified GTM capacity.
So, it should be fairly easy to get an engineer to upgrade your ratings to a GTM of 2600kg, with commensurate increase in ATM. Note (in NSW) that over around 2500kg the annual registration fee jumps up a bit.
-- Edited by Are We Lost on Sunday 11th of July 2021 01:47:39 PM
Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM

So, in this example, how can the ATM go up to 3500kg if the axle rating is still at 2800kg ? Would that need upgrading as well ?

oldbloke · Guru

Many are in this situation. I generally only travel with my tanks with 50 to 100 litres. Enough for two or three nights. Fill up when I arrive. I think its a common practice.

yobarr · Guru

Hi Rob.The increase in axle rating to 3200kg is the reason that the bigger brakes had to be fitted.GTM was then increased to be the same as new axle rating,and ATM went to 3500kg. Perhaps the reason that some manufacturers have ATM at,or lower,than axle carrying capacity is to help buyers who don't understand weights.For example,a car with a towing capacity of 3000kg can legally tow a van with ATM of 3500kg,provided that the weight of the loaded van does not exceed 3000kg.Provided the van's tare is no more than about 2500kg,there still would be reasonable load carrying capacity of 500kg before 3000kg was reached,but if that same van was then towed by a car with 3500kg towing capacity,the van could be loaded to its 3500kg ATM. On the compliance plate I originally showed,you will see that tare is 1740kg,so apparent carrying capacity is 1760kg,which is HUGE. This serves to illustrate that tare weights shown on compliance plates effectively mean NOTHING.Cheers

-- Edited by yobarr on Monday 12th of July 2021 03:40:22 AM

Tony LEE · Guru

Some overweight problems come about after the van leaves the factory. Couple of solar panels and a couple of batteries and an extra water tank can eat up a fair bit of your payload

Radar · Guru

Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM
Ok, thanks for the advice fellas. Sounds like I should get on to a trailer/van engineer, atm changer type person (not sure what theyre called) and see if I can get GVM/ATM increased to reasonable level. FYI , the van already has 12 inch brakes. Although, im not sure what the limit is with single axle trailers, maybe theres a limit there ?

What is a real concern here is the weight on a single axle caravan, the man would need to be very selective about tyres, there would not be many around with 1300 kg plus limit carrying capacity and he would not be able to get them from just any corner store along the way.

My thoughts stand big time, the caravan needs to go on diet to be road safe.

The Brains here go on about tow vehicles with 100kgs over on the drive axle but here is a caravan with how much weight on that single axle 2600kgs.

Our dual axle runs around with about 2550 kgs.

I really have a lot of trouble understanding.

montie · Guru

I would be very surprised if you could find an engineer who would certify an ATM upgrade beyond the Axle Group Rating.
The Axle Group Rating is not set by the van manufacturer rather the chassis/suspension manufacturer so getting an upgrade there might be difficult also.
This brings you back to working within the gross payload allowance of 400kg of which 254kg is taken by the full water tanks so some management there would be a help.

Maybe travel with only one tank full.

The plated ball weight is the measured weight on the ball of the dry empty van as it leaves the factory and is irrelevant. Actual ball weight of the loaded van needs to be managed and will be affected by water tank positioning and load placement in the van.
Check the position of the water tanks to ascertain if one or both are situated forward or behind the axle group.
Ideally the measured ball weight of the loaded van should be around 260kg.

As you are tight on payload capacity it is also possible to carry some weight in the tug so long as you stay under GVM.

RobDor · Veteran Member

Radar wrote:

Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM
Ok, thanks for the advice fellas. Sounds like I should get on to a trailer/van engineer, atm changer type person (not sure what theyre called) and see if I can get GVM/ATM increased to reasonable level. FYI , the van already has 12 inch brakes. Although, im not sure what the limit is with single axle trailers, maybe theres a limit there ?
What is a real concern here is the weight on a single axle caravan, the man would need to be very selective about tyres, there would not be many around with 1300 kg plus limit carrying capacity and he would not be able to get them from just any corner store along the way.
My thoughts stand big time, the caravan needs to go on diet to be road safe.
The Brains here go on about tow vehicles with 100kgs over on the drive axle but here is a caravan with how much weight on that single axle 2600kgs.
Our dual axle runs around with about 2550 kgs.
I really have a lot of trouble understanding.

FYI - the tyres on there are rated 1550kg at 80 psi. Cheers

RobDor · Veteran Member

montie wrote:
I would be very surprised if you could find an engineer who would certify an ATM upgrade beyond the Axle Group Rating.
The Axle Group Rating is not set by the van manufacturer rather the chassis/suspension manufacturer so getting an upgrade there might be difficult also.
This brings you back to working within the gross payload allowance of 400kg of which 254kg is taken by the full water tanks so some management there would be a help.

Maybe travel with only one tank full.

The plated ball weight is the measured weight on the ball of the dry empty van as it leaves the factory and is irrelevant. Actual ball weight of the loaded van needs to be managed and will be affected by water tank positioning and load placement in the van.
Check the position of the water tanks to ascertain if one or both are situated forward or behind the axle group.
Ideally the measured ball weight of the loaded van should be around 260kg.

As you are tight on payload capacity it is also possible to carry some weight in the tug so long as you stay under GVM.

Thanks for the info. Im starting to think managing the water being carried is the go, along with a few items in the car. as I said, i have hardly anything in the van and ideally I would want my food and some drinks in there along with clothing etc, but that is not much weight really, so limiting to one water tank should work, otherwise it defeats the purpose of having a van .Ill still look into it further, just so I know my options. I have plenty of headroom in car GVM and total GCM. Cheers

yobarr · Guru

Radar wrote:

Great post,Stephen,and you have explained everything clearly.Increasing the ATM would not be a problem as the axle group already is rated at 2600kg,so getting an ATM of 2900kg would probably be easy? With 300kg towball weight,there would be GTM of 2600kg if needed,with the BT50 able to handle that well.The picture below shows that,although the axle group has 2800kg capacity,the van's ATM is only 2180kg,and GTM is 1960kg. Tare was 1740kg,so only 440kg carrying capacity,Useless! Minimal work on this van resulted in a 3500kg ATM and 3200kg GTM,but brakes had to be upgraded from 10" to 12".Cheers.

-- Edited by yobarr on Sunday 11th of July 2021 05:03:11 PM
Ok, thanks for the advice fellas. Sounds like I should get on to a trailer/van engineer, atm changer type person (not sure what theyre called) and see if I can get GVM/ATM increased to reasonable level. FYI , the van already has 12 inch brakes. Although, im not sure what the limit is with single axle trailers, maybe theres a limit there ?
What is a real concern here is the weight on a single axle caravan, the man would need to be very selective about tyres, there would not be many around with 1300 kg plus limit carrying capacity and he would not be able to get them from just any corner store along the way.
My thoughts stand big time, the caravan needs to go on diet to be road safe.
The Brains here go on about tow vehicles with 100kgs over on the drive axle but here is a caravan with how much weight on that single axle 2600kgs.
Our dual axle runs around with about 2550 kgs.
I really have a lot of trouble understanding.

Not hard to understand,Ralph.My van tyres are rated at 1550kg,so I could carry carry 3100kg on a single axle.(In theory!other variables may affect this?),and I always run 2300kg on the rear of the car.Had 697 Bridgestones,then BFG KO2s (rubbish) and now Mickey Thompsons.With tyres,like many things in life,you get what you pay for.Cheers

yobarr · Guru

montie wrote:
I would be very surprised if you could find an engineer who would certify an ATM upgrade beyond the Axle Group Rating.
The Axle Group Rating is not set by the van manufacturer rather the chassis/suspension manufacturer so getting an upgrade there might be difficult also.

Given your vast experience with caravans,and your undoubted knowledge and ability with weights etc,Montie,I must admit that I am somewhat surprised by your points that I have highlighted above.Please find three photos of compliance plate,all from the same caravan that was upgraded from 2180kg ATM with 2800kg axle group rating (first picture) to 3080kg ATM,still with the original 2800kg axle group rating.(3rd picture).Later,the axle group rating was increased to 3200kg,and the ATM went to 3500kg. (Last picture).Somehow the last picture has managed to also fit itself between the first and 3rd pictures,but I don't know how to get rid of it! Sorry.Cheers

-- Edited by yobarr on Monday 12th of July 2021 07:36:26 PM

montie · Guru

As already explained not many (if any) engineer's would certify an ATM upgrade above the Axle Group Rating because any excess ball weight would render the van illegal.

An ATM of 3000kg with an Axle Group Rating of 2800kg has a margin of only 200kg ball weight to stay legal.

Most engineers ,like me, would see that as pushing the envelope of safety.

Having said that I know at least one manufacturer who plays the Russian roulette game where they rely on ball weight to comply with AGR.

RobDor · Veteran Member

Ok, for those interested, this is where I stand. I have spoken to an engineer at length, who does these ATM upgrades and from his advice, this is what is possible. The current cruisemaster suspension would need an upgrade from 2.6t to 2.8t, and that is possible at a cost of $1800, new arm each side, new shocks, new springs, new cruisemaster spec plate. The certifier said that all other items seem fine to handle the extra load - brakes, tyres, chassis, chains, hitch etc. Millard also verified chassis is well within spec to handle this. Certifier cost to check and provide mod plate $450. So, up to me now if I want to spend the money and upgrade, or use one water tank when travelling and manage it that way. Cheers

montie · Guru

RobDor wrote:
Ok, for those interested, this is where I stand. I have spoken to an engineer at length, who does these ATM upgrades and from his advice, this is what is possible. The current cruisemaster suspension would need an upgrade from 2.6t to 2.8t, and that is possible at a cost of $1800, new arm each side, new shocks, new springs, new cruisemaster spec plate. The certifier said that all other items seem fine to handle the extra load - brakes, tyres, chassis, chains, hitch etc. Millard also verified chassis is well within spec to handle this. Certifier cost to check and provide mod plate $450. So, up to me now if I want to spend the money and upgrade, or use one water tank when travelling and manage it that way. Cheers

-- Edited by montie on Tuesday 13th of July 2021 11:12:39 AM

montie · Guru

RobDor wrote:
Ok, for those interested, this is where I stand. I have spoken to an engineer at length, who does these ATM upgrades and from his advice, this is what is possible. The current cruisemaster suspension would need an upgrade from 2.6t to 2.8t, and that is possible at a cost of $1800, new arm each side, new shocks, new springs, new cruisemaster spec plate. The certifier said that all other items seem fine to handle the extra load - brakes, tyres, chassis, chains, hitch etc. Millard also verified chassis is well within spec to handle this. Certifier cost to check and provide mod plate $450. So, up to me now if I want to spend the money and upgrade, or use one water tank when travelling and manage it that way. Cheers

Rob,

If I were you I would try managing the 400kg available payload in the first instance and monitor how that works out as I posted earlier.

The Cruisemaster upgrade only gets you an additional 200kg at cost of $1800 and a further $450 for the ATM upgrade. That IMO would be your last resort.

oldbloke · Guru

That's what I do. I also often carry 50 litres in the ute.