Topaz Axle Rating too low?

[Shaker]

I currently have an AOR Quantum & a Tvan. I have been looking a maybe replacing them with a Topaz. There is a 2016 mod on Caravan Sales with a photo of the compliance plate.
It shows the weights as Tare 1760kg, GTM 1980kg, ATM 2200kg, yet the axle load capacity is  only shown as 2000kg, it should be a minimum of 2400kg which is 120% of the GTM as per the requirements under the design rules in VSB1.
How do Track get away with such a poor axle capacity.
Topaz is now off my list.

[Harry Lissimore]

Tell me about it!  I asked some month or two ago about an axle upgrade but haven't heard back yet.
Ask Track, I would be very interested in the answer.

Harry

[Shaker]

Tell me about it!  I asked some month or two ago about an axle upgrade but haven't heard back yet.
Ask Track, I would be very interested in the answer.

Harry

The upgrade shouldn't be up to you, the design rules are very clear, although it appears that they may have changed slightly, it used to be 120% of the ATM.
These problems come as a result of it being virtually a self regulating industry, I can't believe how many campers & vans don't comply in some way, didn't expect it from Track though.

[Auscgu]

Shaker
The 120% relates to dual axle and load sharing not a single axle configuration.

The Topaz complys with VSB1 and treads a fine line between having to fit brakes to all wheels and break away brakes
As soon as you change the axle load you will have to comply with all the extra requirement and add weight
There is no easy way to upgrade the axle rating
The better approach would be to reduce the body weight for more capacity.
Lets hope the mark 3 version achieves this

[Shaker]

If you look at the relevant page you will see that the top left drawing is of a single axle trailer, the 120% applies to it as well.

[Auscgu]

Shaker
The suspension section
Both version 4 & 5 are the same for the suspension section
The 120% is under the heading group of axles and relates to non load sharing suspension setups
This document is ambiguous but note the comment more info is available for load sharing

I rang and spoke to the engineer at Track Trailer regarding this topic as I wanted to have the axle upgraded to 2400 kg
He explained the regs and I came to the same conclusion the the topaz comply's and is able to be licensed in every state of Australia with the current arrangement

The biggest issue you will find no matter which brand you chose is load caring capacity
The topaz claims 700 kg load capacity but once you take out water, gas and any other accessorise you fit from a bare van your lucky to have enough capacity
This is where you need to do some serious research and discuss with the suppliers the issue
The only way this will change is if we have this discussion with people who design the vans

[Harry Lissimore]

AUSCGU,

Are you sure on that tare weight of 700 kg?  My 2015 Topaz Savannah has ATM of 2200 and Tare of 1710.  That leaves 490 kg tare.
Please give me a call.  0417193528

Harry

[Auscgu]

Harry,
I should re phrase that, when I was looking to purchase the saleman stated 700kg load
When you read the specs depending on the options install this is around 500 kg
Once you take the water gas and extras out not much left
900 to 1000 kg would be a better number then we could be sure the van would not be over loaded.

This is the current spec sheet weight section

[Shaker]

Track can say what ever they like, but I won a VCAT case against a manufacturer of a single axle camper trailer with an under-rated axle rating.

[Nomadic]

I'm with Auscgu on this one. There has been a lot of confusion on how VSB 1 is to be interpreted. They have even tried to clarify it with Information Bulletin IB 129  https://www.transport.wa.gov.au/mediaFiles/licensing/LBU_VS_IB_129.pdf
This document doesn't help much with the clarification but it stands to reason axles, wheels and tyres are only derated when more than one axle is installed WITHOUT a load sharing arrangement where it is possible for one axle to carry more weight than the other axle.
The derating not being applicable for a single axle arrangement (otherwise it would be a blanket derating and no need to define the extra conditions).  That being said it is probably worthy noting that wheel diameter impacts the rating of axles and brake components so people need to be aware of any limitations there.

Shaker was your case won on the basis of the 120% rule or the fact the nominated axle rating was less than the ATM(or GTM)?

[Shaker]

It was on the basis that the axle load rating was less than 120% of the ATM.
I will add that it was all on the information contained in VSB1 & no expert evidence was requested.
Doesn't commonsense dictate that the axle load capacity should be in excess of the weight of the trailer? Think of the load on the axle when you hit a washout,

[MYT150]

Just a thought, but as they have independent suspension, is the load rating 2000KG per axle, or in total, i.e. there is technically two axles as they are not connected.

So on a solid axle trailer the load rating is for the axle, but in independent suspension I would expect the rating would be for each stub axle. But maybe I am wrong.

[Phil G]

Gday Aidan,
Axle ratings are "per pair of stub axles".

We all know how good MC2 suspension is, but the 2000kg axle limit is holding back the development of the Topaz.
Other single axle independant suspensions such as Vehicle Components are rated up to 2800kgs.  So other similar hybrid vans (eg Exodus 14) have a Tare of 1840kg, an ATM of 2500kg so a payload of 660kgs.  They use a suspension rated at 2600kg, which is is about 110% of GTM.  Need a good payload these days because of the increased policing of weights.

EDIT:  Just to add my reading of that poorly worded section in VSB1 is that the 120% only applies to non-load sharing axles in a group. 
It seems very rare for a caravan to have an axle rating greater than 120% of GTM.  My single axle offroad caravan has an axle rating of 2500kg and a GTM of 2360kg - that's only 106%.

[Gryphen]

Even their description are confusing, they talk about the trailer being at its ATM, and then mention 120%, but also being 'equal to the load' both at ATM.

1. at least 120% of the load on that axle with the trailer at its ATM; and
2. at least equal to the load on that axle with the trailer at its ATM and any retractable axle retracted.

Question though, is the Axle max load when free standing or when attached to the tow vehicle, because of course the load on the hitch is load upon the tow vehicle and not on the axle of the trailer.

[Shaker]

Forget the reference to load sharing & non load sharing, we are talking about single axle trailers that appear in the diagrams above the description.