S Value on tow hitch of caravan

[Heethers]

Am l correct in saying the S value on the tow hitch is maximum nose weight the hitch can take, example mine is 150.

l take it that is 150kg, or am l not correct and where do l find the nose weight of the caravan.

l know what my Shogun is but unsure of the van.

l read this in this months PC or am l reading it wrong.

NigelH

 

[Hamer_5041128]

NGH,

The maximum nose weight of an Alko Chassis is 100kgs. Therefore even if the car has a maximum tow bar nose weight of 150kgs, if the caravan has an Alko chassis the maximum nose weght on the towbar is 100kgs.

Hamer

 

[Heethers]

Thanks Hammer what is the Svalue referring to.

NigelH

 

[Lutz]

The definition is as follows, quote:

"The static vertical load S in kg is the proportion of the mass of the centre axle trailer exerted under static contions at the coupling point"

To you and me that is the noseweight.

 

[Heethers]

Lutz on my ALKO chassis it states S 150 is this Kg at the coupling head or am l reading it wrong, Hammer states the ALKO has a maximum of 100 Kg at the coupling head.

NigelH

 

[SteveW77]

100Kg is the maximum nose weight if your caravan is fitted with an AL-KO stabiliser hitch such as the AKS 3004 ( ordinary tow hitches may be different, not sure. ) The lower of the two figures is the one to abide by, so with an AK-LO chassis fitted with a stabiliser hitch 100Kg is the maximum allowed what ever the nose weight of the car/towball.

Steve W

 

[Heethers]

I am really confused now, l have the 3004 ALKO Stabiliser fitted at manufacture, is their a ALKO site l can visit to bottom this question, l can make 100kg no problem but l have read that 7% of the maximum you are allowed gives for better towing.

With me that would be the Shogun Nose weight which is considerably higher than 100 KG and a lot lower than 150 Kg somewhere in between, which is it.

Would be grateful if someone could answer this for me.

NigelH

 

[SteveW77]

Just google al-ko kober and when the site opens go to vehicle technology.

I don't see the problem, AL-KO quite clearly state that 100Kg is the maximum nose weight for their Chassis with a stabiliser hitch.

Steve W

 

[Lutz]

The coupling head may well have a different max. noseweight to the caravan chassis, but the lower of the two limits counts. Likewise, the towbar may also have a different limit to what the car manufacturer specifies, but here again the it is the lower of the two that applies. In the end, it is always the lowest limit that must be observed, no matter which one it is.

 

[Heethers]

Thanks all for your help, l will maintain the 100kg

 

[ProfJohnL]

Hi NGH,

Nose weight is the result of the caravans centre of gravity (CoG) being forward of the main axle. This is the preferred arrangement as it aids stability.

It is generally accepted that the greater the nose weight the more stable the outfit, but there is little point in maximising the nose weight if no further benefit is produced.

The majority of caravans seem to tow quite well when set to about 70Kg, so I suggest you try reducing you nose weight until you feel it is less good, and the add a few Kg for a safety margin.

 

[Heethers]

Thanks John seems tow best around 90Kg, tried it around 85 seemed to bounce a little.

Also was towing nose down a little the Shogun Tow bar has two settings, have lifted it up to the next to be more level, mainly to stop the Jockey wheel grounding on those bloody sleeping policemen.

See how it goes next Wed off for the Bank Holiday

NigelH

 

[Lutz]

Thanks John seems tow best around 90Kg, tried it around 85 seemed to bounce a little.

Also was towing nose down a little the Shogun Tow bar has two settings, have lifted it up to the next to be more level, mainly to stop the Jockey wheel grounding on those bloody sleeping policemen.

See how it goes next Wed off for the Bank Holiday

NigelH

It is hard to believe that 5kg should make so much difference. Error in measurement must amount to about the same.

 

[Heethers]

Lutz, lifted the tow ball up by 25mm, caravan now sits level, got a nose weight of just under 100kg using the new melenco gauge, towed a good 20 miles and it felt a lot better, wasn't bad before but even better now.

I am off to Sandringham in June and from Cheshire across country will be a good test on how she handles has its very little motorway driving only about 30 miles the rest on A roads.

NigelH

 

[Lutz]

It seems a bit strange that you were able to lift the towball up by as much as 25mm and still be within the prescribed limits for towball height. The centre of the towball should be no more than 420mm from the ground when the car is fully laden. It would, of course, be higher at kerbweight.

 

[Heethers]

Lutz l guessed it was about 25mm will check later today, its a factory fitted Mitsubishi tow bar for the Shogun, l asked was that the correct position of the tow ball, they said check if the caravan sits level if a little nose down lift to the next position, which l have done it now sits level.

When l towed in the 80's we used to get drop plates for the different cars so has to have the van level, l believe now there is a tolerance to adhere to, surely factory fitted tow bars will be to this tolerance regardless that you are on the lower or bottom positions.

By the way l believe Mitsubishi have Witter to manufacture the to bars.

Thank you for your advice l will let you know what it is set to later today.

NigelH

 

[Lutz]

Towball and coupling height within tolerances can, but need not necessarily, result in the caravan being level. Nominally the caravan would be slightly nose down, but even a slight nose up attitude could be within specified limits.

 

[ProfJohnL]

Hi NGH

The EU regulation of coupling heights applies to private non-commercial vehicles, some of the larger 4x4 have commercial applications, and thus may be exempt from the 350 to 420 mm limits. This may apply to your Shogun, but you would have to check with manufacture about it's status in this regard. It may explain how the manufacture can legally provide a multi-position fixing plate.