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Nose Weights


Griff

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Hi,

 

How do you TA owners find the best way to acheive measurement of nose weight?

SA's are straight forward as it remains more or less constant irrespective of attitude.

Presumably it is measured at a predetermined height position relative to the towball height as it alters according to pitch angle?

Stay safe - Griff.  :ph34r:

Wheels at the front Green Oval Towing Machine

Wheels at the back Bessacarr 845

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Presumably it is measured at a predetermined height position relative to the towball height as it alters according to pitch angle?

46173[/snapback]

Spot on. ..

It's just the same as a single axle caravan. Set the caravan level on a level surface and measure the noseweight with a gauge placed immediately under the hitch.

Regards,

Gordon.

Fourwinds Hurricane 31D Motorhome. Also MGTF135 1. 8i Roadster (fun) & Volvo V70 3.2Ltr LPG (everyday car)
Unless otherwise stated, my posts will be my personal thoughts and have the same standing as any other member of Caravan and Motorhome Talk.

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Spot on. ..

Set the caravan level on a level surface and measure the noseweight with a gauge placed immediately under the hitch.

46224[/snapback]

Gordon,

 

Not sure that I m following this.

 

If say on level ground the tow hitch is the same height as the tow ball, the nose weight is theoretically zero.

I am basing this on my assumption that with the jockey wheel up on a TA, the hitch would not rest on the ground or would it?

 

If I load the van such that the hitch is say 2 inches lower than the towball then lift the hitch to the same height as the towball with the jockey wheel up and then measure the downward force, does this then not represent the nose load when connected based on the assumption that unlike a SA, with a TA the higher you lift the hitch the greater the downward force?:unsure:

 

A SA downforce for the same load distribution will remain the same irrespective of the height lifted (within reason)

Stay safe - Griff.  :ph34r:

Wheels at the front Green Oval Towing Machine

Wheels at the back Bessacarr 845

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I can tell you the Louisiana weight as I one. It's a 112 so Baileys came back to me with after I contacted them.

 

By the way this just happens to fit the 7% rule ;);)

 

 

PS:- I had to reset the height of my bar as it was at a differing height to my previous SA Ace.

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The truly accurate way of measuring nose weight on twin axles is to load up the van and car and have the caravan attached. Now measure the height of the drawbar from the ground to any convenient point. Unhitch the van and move the car forwards. Then using the jockey wheel lower the coupling down onto the gauge until the height from the ground is the same as measured when hitched and the reading on the gauge is the true noseweight.

 

One word regarding stability, please ensure that when hitched up with a twin axle the drawbar should be parallel with the ground or facing slightly down. It must never, ever, point up towards the car.

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Hi,

 

How do you TA owners find the best way to acheive measurement of nose weight?

 

46173[/snapback]

Get a nose weight gauge locate into hitch cup, read measurement. ...........same as I did for my single axle caravan.

I think unless you have a ‘squinnie’ towing vehicle (which you shouldn't have pulling a twin axle) the odd kg shouldn’t make too much difference!!!

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The truly accurate way of measuring nose weight on twin axles is to load up the van and car and have the caravan attached. Now measure the height of the drawbar from the ground to any convenient point. Unhitch the van and move the car forwards. Then using the jockey wheel lower the coupling down onto the gauge until the height from the ground is the same as measured when hitched and the reading on the gauge is the true noseweight.

 

One word regarding stability, please ensure that when hitched up with a twin axle the drawbar should be parallel with the ground or facing slightly down. It must never, ever, point up towards the car.

46280[/snapback]

This is a good idea, but relies on the spring rate of the cars suspension being the same as the noseweight gauge,which of course it isn't. Taken to the extreme,if you placed the hitch on a pile of bricks,the depression would be zero,but the noseweight could be anything.

 

The most accurate method that I can see is the load cell between the ball and the hitch,but those available from caravan accessory outlets are not noted for their accuracy.

 

It would be interesting to know what happens if the jockey wheel is wound right up. Does the hitch eventually touch the ground or does the twin axle suspension react the noseweight to the point where the jockey wheel is clear of the ground,ie no noseweight. If this is the case then the noseweight of a TA van will vary sustantially with height unlike a single axle van.

 

I think the most realistic value will be obtained by loading the van so that a noseweight using a standard gauge, is approaching the lower of the of the 2 limits,be it car hitch or van drawbar.

 

Frank

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Like Gordon I don't see any difference in the way you measure noseweight between a single axle and twin axle. Simply set the caravan on level ground at the same height as it would be when connected to the towing vehicle and either use a purpose made noseweight gauge or block of wood and bathroom scales under the hitch with the brake off and the jockey wheel off the ground.

 

I don't believe there would be a significant difference in noseweight with height, within reason. Perhaps someone with time and a twin axle axle would care to measure the noseweight say 6" above and below the normal height to see what the variation is.

 

Brian

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PS:- I had to reset the height of my bar as it was at a differing height to my previous SA Ace.

46273[/snapback]

 

John,

 

Just out of interest, what height is your towball above ground unladen.

 

Not sure if mine can be adjusted if necessary.

Stay safe - Griff.  :ph34r:

Wheels at the front Green Oval Towing Machine

Wheels at the back Bessacarr 845

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Gordon,

Not sure that I’m following this.

If say on level ground the tow hitch is the same height as the tow ball, the nose weight is theoretically zero.

46272[/snapback]

Really? Surely, this would only be true if the axles were placed exactly at the balance point of the caravan, and in reality, this is not true. Axles are normally placed to the rear of the balance point, a) to ensure a positive noseweight when the caravan is unladen and B) to minimise the loading to the rear of the axle line.
I am basing this on my assumption that with the jockey wheel up on a TA, the hitch would not rest on the ground or would it?

46272[/snapback]

Since the axle is placed slightly to the rear of the centre line, it certainly would with a single axle caravan. With a twin, as the hitch is lowered the fulcrum moves forward as weight is transferred from being shared between the two axles, to mostly being supported by the front one. The front axle is slightly forward of the centre line and so the hitch never actually touches the ground, although it is very close if the jockey wheel is lifted clear of the ground!
If I load the van such that the hitch is say 2 inches lower than the towball then lift the hitch to the same height as the towball with the jockey wheel up and then measure the downward force, does this then not represent the nose load when connected based on the assumption that unlike a SA, with a TA the higher you lift the hitch the greater the downward force?:unsure:

46272[/snapback]

I think there’s a little confusion here. Yes, the noseweight will increase slightly as the hitch is raised since the fulcrum of the caravan is moving towards the centre of the rear axle, and a greater length of the caravan body is being supported at the front hitch. This is compensated to a small degree by the length of the lever being increased too. Likewise lowering the hitch will give a slightly lower noseweight, since the fulcrum is now closer to the centre line of the front axle, and hence less of the caravan body weight is being supported by the hitch. It is because the weight of the caravan is not shared evenly between the two axles that these axles are down rated when used in a twin configuration. (eg a 750Kg Al-Ko axle is only rated at 650Kg)

These ideas are all fine in theory, but the variation in static noseweight is minimal within the normal vertical movement of the hitch. For all practical purposes, a twin axle caravan should be treated in exactly the same way as a single axle. ie level ground, level caravan, and measure the noseweight directly at the hitch.

I hope I haven't confused you further.

Regards,

Gordon.

Fourwinds Hurricane 31D Motorhome. Also MGTF135 1. 8i Roadster (fun) & Volvo V70 3.2Ltr LPG (everyday car)
Unless otherwise stated, my posts will be my personal thoughts and have the same standing as any other member of Caravan and Motorhome Talk.

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as the hitch is lowered the fulcrum moves forward as weight is transferred from being shared between the two axles, to mostly being supported by the front one.

46361[/snapback]

Thanks for your comprehensive explanation Gordon.

My thinking seems to be off the mark in as much as I thought that the idea of a Twin Axle was to spread the load as best possible over both Axles during transit.

In other words the C of G would be near midway between both which is why I imagined that with jockey wheel up, it would just sit there.

No doubt will sink in when I get mine.

Stay safe - Griff.  :ph34r:

Wheels at the front Green Oval Towing Machine

Wheels at the back Bessacarr 845

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In other words the C of G would be near midway between both which is why I imagined that with jockey wheel up, it would just sit there.

46381[/snapback]

I have a small twin axle trailer and that's exactly what it does do! In fact there isn't even a jockey wheel fitted, it naturally rests with the hitch about an inch lower than the rear, and the only noseweight is that of the A-frame.

I'm sure that it will all make perfect sense, when you've had time to "play" with a twin axle caravan. You imply that purchase of one planned soon. What are you getting?

Cheers,

Gordon.

Fourwinds Hurricane 31D Motorhome. Also MGTF135 1. 8i Roadster (fun) & Volvo V70 3.2Ltr LPG (everyday car)
Unless otherwise stated, my posts will be my personal thoughts and have the same standing as any other member of Caravan and Motorhome Talk.

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I'm sure that it will all make perfect sense, when you've had time to "play" with a twin axle caravan. You imply that purchase of one planned soon. What are you getting?

Cheers,

Gordon.

46391[/snapback]

Gordon,

Its a Bailey Senator Louisiana due mid Jan and weather permitting??, it'll be off to the Lakes or Cotswolds (250 mile round trip) for a few days straight after picking it up which is why I am trying to get the loading theory right in my mind.

From there straight into storage so not much chance for a play around afterwards.

Stay safe - Griff.  :ph34r:

Wheels at the front Green Oval Towing Machine

Wheels at the back Bessacarr 845

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Gordon,

Its a Bailey Senator Louisiana due mid Jan and weather permitting??, it'll be off to the Lakes or Cotswolds (250 mile round trip) for a few days straight after picking it up which is why I am trying to get the loading theory right in my mind.

From there straight into storage so not much chance for a play around afterwards.

46403[/snapback]

Lousiana? That's the one with the fixed bed at the rear. You'll hate it! :D So you would be better off giving it to me, I'll look after it for the winter for you :rolleyes:

Seriously, I think you've chosen well so I trust that it will give you years of service.

All the best,

Gordon.

Fourwinds Hurricane 31D Motorhome. Also MGTF135 1. 8i Roadster (fun) & Volvo V70 3.2Ltr LPG (everyday car)
Unless otherwise stated, my posts will be my personal thoughts and have the same standing as any other member of Caravan and Motorhome Talk.

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  • 2 weeks later...
Like Gordon I don't see any difference in the way you measure noseweight between a single axle and twin axle. Simply set the caravan on level ground at the same height as it would be when connected to the towing vehicle and either use a purpose made noseweight gauge or block of wood and bathroom scales under the hitch with the brake off and the jockey wheel off the ground.

 

I don't believe there would be a significant difference in noseweight with height, within reason. Perhaps someone with time and a twin axle axle would care to measure the noseweight say 6" above and below the normal height to see what the variation is.

 

Brian

46298[/snapback]

 

With a twin axle van, there is a HUGE difference in noseweight if its 6" higher or lower. Just try lifting one 6" higher than the position where is sits naturally I. E no noseweight. You'll probably need a back operation!

 

Tall Limey has it exactly right. But then he should! He and I were at a road side check with Nottinghamshire police when exactly this scenario cropped up. ...

 

Regards

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With a twin axle van, there is a HUGE difference in noseweight if its 6" higher or lower.   Just try lifting one 6" higher than the position where is sits naturally I. E no noseweight.   You'll probably need a back operation!

 

Tall Limey has it exactly right.   But then he should!  He and I were at a road side check with Nottinghamshire police when exactly this scenario cropped up. ...

 

Regards

47648[/snapback]

 

Hi Guys,

 

Having owned both twin and single axle caravans, measuring the nose weight is exactly the same.

 

The nose weight for either is the downward force applied by the towing head of the caravan, at a height exactly equal to the height of the towball on the car, measured on level ground.

 

Once the caravan was correctly loaded to achieve this, then the only time the nose weight would change would be if you then measured it for hitching onto a car with either a higher or lower towball height.

 

It really is that simple

 

With our twin Senator Camargue when correctly loaded you could lift the jockey wheel completely and the caravan just sat slightly nose down.

For ease of manouvrability I always would wind the jocket wheel right down to put most of the weight on the back axle, this made it easier to push around and reduced the scrubbing effect from the front wheels.

 

Cheers

 

Steve

Jaguar E-Pace 180D HSE R Dynamic - 2008 Swift Conqueror 540

 

"Unless otherwise stated, my posts will be my personal thoughts and have the same standing as any other member of Caravan Talk"

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