Towing capacity T5 - something to consider

[petenkaz]

Pretty unhappy, have a Kombi Beach, and today finalised a deal on a Jayco campervan. When I went in to discuss getting trailer brakes added it turns out that the towball weight maximum on the VW is 100 kgs, the van is 120 kgs, total weight 900 kgs. This means that it is illegal to tow the van with my car.

The local VW people were their usual friendly selves, jumping out of their skin to answer all my questions (not!), however sadly there is nothing that can be done to increase capacity. Bit of a bummer cause i've always bragged to mates how much it can tow. Turns out an auto Xtrail has better capacity, though I know which i'd prefer to be towing with!

Something for all to keep in mind when towing....

[Cousin]

petenkaz, is your towbar/ball genuine, or aftermarket.

Aftermarket bars start at around 1200kgs for the Multivan and go up over 2.5 tonne

I don't know the figures for ball weight for these bars, but I'm sure someone here will know

Maybe have a chat with someone from Hayman Reece?


M

[dct]

It looks like the standard Hayman tow bars max out at 100Kg too.

VW Transporter Tow Bar Sydney

David

[Seano]

Fair to say that you may have bought the wrong caravan. There's nothing wrong with the vehicle. The problem is that the Jayco van is poorly balanced so that its drawbar weight is too heavy. I reckon 120kg down on the towbar is ridiculous for such a lightwweight caravan...

Solution? Easy. Ask the Jayco dealer to re-balance the caravan so that the towbar weight comes in under 100kg. Which means whacking a few kgs at the rear of the van...

[jfoldbar]

i have a t5. hayman and reese tow bar rated at 2500kg. often pulling 2 axle trailer loaded with over 2 tons in it

[4wheels]

i have a t5. hayman and reese tow bar rated at 2500kg. often pulling 2 axle trailer loaded with over 2 tons in it

That's fine, but it's the towball weight/downforce that's at issue. Apparently, a lot of European (and some Japanese) vehicles are designed with a lower towball weight in mind, even though they are rated to pull a heavy weight overall (and it's 2.5tonne for most T5s). Australian trailer/caravan manufacturers like to put 10% of the total weight on the drawbar, which means that while the van will pull it, it's over-spec on towball weight, which raises safety issues (taking weight off front wheels) and therefore insurance issues.

Brian.

[jfoldbar]

gee brian, you make it sound like a science. i must be real thick, but i dont have a clue what you mean. taking weight off front wheels, sure this is an issue in theory, and only reality if you want to tow at high speed. if your worried about safety or insurance or something then drive slower so you feel safe and its therefore not an issue.
but as i said, i dont really undertand all the jargon or laws etc, i just know what i do and feel comfortable doing. on the open road with a load i wouldnt be game to go more than about 100 with a full load, half load is better though.in build up areas just allow more room to brake. when i had my trailer built though i did ask for longer draw bar which does cut down on the dancing.
actually the biggest, and only problem i ever have when pulling trailer is not weight etc, but i think 1st gear is too high. i gotta ride the clutch a bit on hill starts to get it moving. and gear doesnt hold going down a hill. a big long hill your brakes may shudder a bit.

adrian

[The_Hawk]

you make it sound like a science.

Well it sort of is a science... Engineers spend lots of time (and money) in buidling and testing certain configurations to ensure they work appropriately. Much like any lever, if you put weight on one side the other side will react. They tell you what the limits are for a reason. I'd like to think there is a bit of leeway in the limits, so +20% or so wouldn't be unreasonable to guess at, but it's not something I would be relying on.

[Mountainman]

The 10% of tow weight over the towball is a widely accepted rule that works well and is almost critical to stable and safe towing. Just drive behind a trailer that is not well balanced to see how dangerous it is to ignore this rule. The problem in Australia is most loaded trailers are way over the 10% towball load and need to use a levelling set-up. Getting the balance right in the first place should take priority.

[Sherwy]

The 10% of tow weight over the towball is a widely accepted rule that works well and is almost critical to stable and safe towing. Just drive behind a trailer that is not well balanced to see how dangerous it is to ignore this rule. The problem in Australia is most loaded trailers are way over the 10% towball load and need to use a levelling set-up. Getting the balance right in the first place should take priority.

I agree, 100kgs ball weight is way too much.. should be half that.

[Peter Jones]

Actually the 10% thing is pretty much urban legend, there's not a lot of science behind it. It's not even mentioned in the ADRs applicable to trailer design.

The Tow ball weights on the European cars are based on science though.

I've previously a bit of reading on the back ground and found this quote here

Among all these very precise guidelines is one major variable: tow ball load. There’s a convention that sets tow ball load at around 10 percent of the trailer ATM, but this rule of thumb developed in the days of small trailers. It’s still the practice by many North American and Australian trailer makers to specify 10 percent loadings for heavy trailers, but in Europe, where there has been considerable testing done, the tow ball load range is specified in EC E94/20 regulation as a minimum figure of 25kg and a maximum of 100kg, for trailers up to 2000kg ATM. Even above that figure the heaviest gazetted coupling for cars, light commercials and 4x4s is rated at 120kg tow ball load.

Not being one to blindly accept stuff I read on the internet I looked up the referenced regulation Directive 94/20/EC but I can't extract the same opinion on first glance, there's a few calculations to be done. I'll figure it out one day. It's an interesting read though, gives you a new appreciation of the engineering involved.

In answer to the original question though, it's pretty easy to balance the trailer (caravan) to drop the tow ball weight, you just need to pack all the heavy stuff in the rear behind the axle.

A ball weight scale only cost about $20 from a caravan shop, but you can also use bathroom scales to measure the load.

Just put an axle stand on top of your bathroom sales and adjust to read zero, and place it under the ball hitch. That's the ball weight!

On my tandem car trailer moving the car on it back and forth 4 inches will alter the ball weight from negative to 85kg.

I'm towing 1400kg with 85kg on the ball no issues. That's 6% ball weight.

[jfoldbar]

so let me get this right, you mean to say that manufacturers make trailer or caravan so that 10% of total weight is pushing directly down on the tow ball.(asuming level groung with car not moving) so lets say if the van/trailer weighs 1500kg then 150kg of that weight is on the tow bar and the other 1350 kg is over the trailer axles.so while it can pull the required weight along its not actually carrying the wieght.and your saying that some car manufacturers put the total allowable downward weight on the tow bar as 100kg. meaning the safe trailer load is 1000kg. this couldnt be the case cause i could blow all your theorys out the window.
so what then does the 10%rule mean.
by the way, i didnt learn about pulling a trailer from a book. as with most things in life, i learnt it from reality.

[Peter Jones]

so let me get this right, you mean to say that manufacturers make trailer or caravan so that 10% of total weight is pushing directly down on the tow ball.(asuming level groung with car not moving) so lets say if the van/trailer weighs 1500kg then 150kg of that weight is on the tow bar and the other 1350 kg is over the trailer axles.

Yep, That's how Australian vans are designed.

so while it can pull the required weight along its not actually carrying the wieght.and your saying that some car manufacturers put the total allowable downward weight on the tow bar as 100kg. meaning the safe trailer load is 1000kg. this couldnt be the case cause i could blow all your theorys out the window.

Also correct, the design of Aussie trailers is based largely on folklore, European cars are designed according to different engineering principles.

An Australian built 1000kg trailer is designed to place 100kg (10%) on the ball.

A European car, a Tiguan for example is rated to tow 2000kg but only allows 100kg on the ball. (5%)

so what then does the 10%rule mean.

Only that Australian design rules are way behind the rest of the world. Child restrain anchors are another example where the more modern ISO fix system doesn't comply with the ADR's inferior requirements.

by the way, i didnt learn about pulling a trailer from a book. as with most things in life, i learnt it from reality.

I learnt about pulling a trailer form real life too, I designed and built my own tandem trailer, consulted on the design with an automotive engineer, researched the ADRs and European trailer standards, fitted my own tow bars and have towed all sorts of trailers many 1000's of km.

The 10% thing is a nonsense. The new Amarok is rated to tow 2800kg does anyone really expect that to mean a ball weight of 280kg?

What about "dog" trailers that have a wheel at each corner? I've seen those rated at 2500kg and they put about 5kg on the ball.

Clearly you've got to have some weight on the ball. I say balance the trailer to put the max allowable down force as specified by the vehicle manufacturer and tow whatever weight the car's capable of.

I'm right on the max capacity of 1400kg with my Bora and I run the ball weight at around 80-85kg pulled the race car to Benalla a couple of weeks ago with no dramas.

My money's on VW engineers to specify what the car can do.

[Guy_H]

Pics of my T5 towbar that has been engineer re enforced & certified to a 230kg ball weight:

Updates on our Dual cab

Had to have it done properly - we tow cars / trailers & wanted to ensure insurance coverage

[Guy_H]

Petenkaz,

Mine was done in Brisbane as well - mind you, I had to do a heap of searching to find out who / where to get it done.