Thread: Bouncing when towing

Originally Posted by Pedro_The_Swift

Yep,, the Caravan Industry standard,,

what does my mate have on his tag line??,,

tell a big lie, tell it often, advertise the **** out of it, and people will believe it,,


remember,, they dont build these things to tow---
they build them to make the centrefold of "Home Beautifull"
and then they just bolt 4 wheels on anywhere--
( oh yes they do-- to adhere to your 10 thing,,)

I'd love to read your Technical papers for 10%,,

Love to..

Not sure what technical paper would satisfy you?

Would you think ALKO may know a thing or two more about towing than you and I combined.

This is on their web site:
How to measure your trailer’s towball mass
Theoretical towball mass is calculated as ATM less GTM. However, the general rule of thumb is that it should be about 8 to 10 per cent of your fully laden trailer. Another indicator is the relationship between towing vehicle and trailer – ideally, both will be level while they’re coupled.

• Towball weight scales: For heavier trailers and perhaps for those towing more often, towball weight scales will give a much more accurate reading.
• Weighbridge: Sit your uncoupled trailer’s jockey wheel on a weighbridge with the wheels off the weighbridge. This is called ‘split-weighing’.

Here is the link: Understanding Tow Ball Weight | Without A Hitch

...and Maybe Hayman Reece may know a few things as well?

How can I check my ball weight?

Ball weight refers to the weight on the front end of the trailer not carried over the axles. As a rule you should aim to have 10 percent of the total trailer weight as ball weight. This can be measured at a weigh bridge by resting the jockey wheel only on the scale.
Alternatively Hayman Reese distributors have a Ball Weight scale with which you can measure your ball weight by placing it under the coupling and winding the weight off the jockey wheel.

Link: Frequently Asked Questions - Frequently Asked Questions - hayman reese

I think aiming for around 10% is a good place to start with stability...but not the only factor,

Originally Posted by Pedro_The_Swift

Yep,, the Caravan Industry standard,,

what does my mate have on his tag line??,,

tell a big lie, tell it often, advertise the **** out of it, and people will believe it,,


remember,, they dont build these things to tow---
they build them to make the centrefold of "Home Beautifull"
and then they just bolt 4 wheels on anywhere--
( oh yes they do-- to adhere to your 10 thing,,)

I'd love to read your Technical papers for 10%,,

Love to..

Is this aimed at the trailer industry? I am not sure what your point is.

Australian Off Road make camper trailers for off road use and also off road caravans, and their owner recommends the Disco for a tow vehicle. Because he uses one.

As far as trailer loadings, they believe heavy weight on the tow bar is much safer. So they normally achieve a minimum of 10% of the trailer weight onto the tow ball.

My Disco does bounce though - on some concrete roads. It sort of goes up and down a bit ... quite strange. There seems to be a frequency from the rise and fall of the sections of concrete road. It happens rarely, but it has happened, and always on a concrete road.

But - the originator of this thread seems to have gone ...

Thanks all, been bush so internet intermittent at best.

• Tyre pressures - I run them at 45-50psi rear and 40psi front following some other posts from this thread.
• Tow ball weight - I've got a ball weight scale and measure as I change things around in the van - seems to sit 180 - 200kg. I haven't found any real definative regulation that says 'thou shalt not exceed the ball weight of the caravan' but am twitchy regarding potential insurance claims. Will look at upping the weight in a trial some time.
• Could my brakes be grabbing on the van? Never thought of it so will investigate, though Im not quite sure how yet.
• I've got it booked in at Pedders for a suspension check as was suggested, its in a weeks time so I'll report back what comes up.

Thanks for all the suggestions, will keep nutting it and report back.

More random thoughts:

• Is your D4 suspension calibrated to the correct heights?
• Any chance you have an anti sway device fitted to the van that is maybe causing the brakes to grab?
• When the back bounces, does the front of the car move in the opposite direction up or down?
• 180-200 ball weight does is not excessive & well within the 350 allowed.
• Did you use a WDH with your previous setup? I have never used one but I am led to believe that it takes out some of the movement around the tow ball by stiffening the connection to the tow vehicle.

Good luck.

My late 2014 Disco - when its on some concrete roads - sort of goes up and down, both front and back together. It feels not smooth - sort of a soft jerkiness. Even when the mileage was at 10k, I felt it. So its not the shockers, or the trailer. It only happens on concrete roads too. And only on some of them. Hence I think its a sort of cycle like a harmonic, but with the suspension. If I had LLAMS I'd lower the vehicle and see if that affected the behaviour.

its so rare though that its not a problem.

FWIW this may not simply be a LR problem. A common thread here seems to be concrete roads. The phenomenon outlined reminds me of travelling along a long stretch of road on the northern NSW coast many years ago. The roads were concreted because of regular flooding and everyone's car bounced up and down over that stretch. Just my two cents worth.

Martin

Originally Posted by letherm

FWIW this may not simply be a LR problem. A common thread here seems to be concrete roads. The phenomenon outlined reminds me of travelling along a long stretch of road on the northern NSW coast many years ago. The roads were concreted because of regular flooding and everyone's car bounced up and down over that stretch. Just my two cents worth.

Martin

Yeh ... A way around it would be to go a lot faster. Problem with that might be fuel plus a $400 fine!! Best to put up with it but fortunately, such concrete roads are not very common.

The complainant (thread starter) has not mentioned concrete roads though - its been myself that has mentioned the concrete roads. But I do know that I have had a vertical oscillation when towing, and its only happened on concrete roads, and also that its only been occasional concrete roads. I think there were some concrete roads going from Brisbane to Byron Bay ... I got some there (coming back towards Brisbane after the Blues Fest). Not on all sections of the concrete roads though. I am very aware of it - but my wife (who is in the front passenger seat) doesn't even notice its happening.

I could ask the Australian Off Road site for owners, and see if its happened to them - some of those guys travel huge distances. The only negative with doing so, is that the Land Rover is a bit unusual, and Toyota guys will have a big laugh ...

There's an older section of the M1 at the Gold Coast where the concrete must have moved and we get some up/down when towing the camper trailer.