Nose weight...

[Marky 1971]

Hi all,
I’m looking for some advice please. I have just bought a 2016 Lunar Cosmos 544 (Quasar dealer special). My previous van had a weight gauge on the jockey wheel, so for this one I bought a kampa gauge. I was surprised to find that with only one small gas bottle in the front the nose weight read nearly 100kgs. The only few bits and pieces in the van are under the french bed which is behind the axle. Given that there is virtually no payload in front of the axle, this weight seems high to me. Could this be right, or should I cast a suspicious eye on a cheap scale? Thanks in advance...

 

[Beehpee]

Check the figures using bathroom scales then you can use the other way but knowing roughly how incorrect it is.

 

[littlebasher]

My Solaris (Quasar dealer special) seems particularly nose heavy (or rather, heavier than i would have expected)

Suspect your gauge is probably right !

 

[Marky 1971]

I will check with the bathroom scales. I need to lose around 10 kilos off the nose if the 95-ish kg weight is correct. The car towball specification is the limiting factor. Is it reasonable practice to load slightly behind the axle to achieve this? I’ve never had this issue before- my previous van was light on the nose.

 

[Hutch]

I have loaded behind the axle to suit, but just be carefull not to overload the van.
Some times just filling the toilet header will give you a 10 kg nose weight difference.

 

[Beachball]

We always load heavy items low down over the axle in our caravan to each its own

 

[Buckman]

The Kampa nose weight gauge is probably a waste of money going by the quality of some of their products so no wonder it is cheap and not so cheerful. The bathroom scale is a good method, but we prefer less hassle and have the Milenco calibrated nose weight gauge.
Best time to chekc nose weihgt is when caravan is loaded as if you are about to go away. Most caravans aer nose heavy when empty. Nose weight should as a guideline be between 5-7% of the MTPLM.

 

[RogerL]

The Kampa nose weight gauge is probably a waste of money going by the quality of some of their products so no wonder it is cheap and not so cheerful. The bathroom scale is a good method, but we prefer less hassle and have the Milenco calibrated nose weight gauge.
Best time to chekc nose weihgt is when caravan is loaded as if you are about to go away. Most caravans aer nose heavy when empty. Nose weight should as a guideline be between 5-7% of the MTPLM.

Our Lunar Clubman ES is the opposite, nose light when empty and not easy to get enough weight forward when loaded - we don't use an awning so can't vary it's position.

I do wish that caravan manufacturers would use the 150 kg A-frame instead of the 100 kg one - more noseweight is good for stability but even cars with 140+ kg limits are usually towing caravans with a 100 kg limit.

5-7% isn't "optimum" it's just the usual range that modern caravans can manage.

 

[Raywood]

I would double check the nose weight with the bathroom scales or another gauge. !00 kg could be right and if so you may have to adjust the load, but do not put lots of weight at the rear. Only by double checking with another device can you be sure if yours is right although if you et a seriously different figure from the second you still only know one is wrong but not which. I do agree that the best way to sort it may be when the caravan is fully loaded and you can see what you get then.

 

[otherclive]

Our Lunar Clubman ES is the opposite, nose light when empty and not easy to get enough weight forward when loaded - we don't use an awning so can't vary it's position.

I do wish that caravan manufacturers would use the 150 kg A-frame instead of the 100 kg one - more noseweight is good for stability but even cars with 140+ kg limits are usually towing caravans with a 100 kg limit.

5-7% isn't "optimum" it's just the usual range that modern caravans can manage.

Considering the majority of vans are 100 kg chassis nose limit and so would be the majority of cars too, why spend extra on surplus outfit weight when it’s not required. Caravanners have safely been towing for years and I really don’t see any basis for changing. Id suggest that a car with a 140+ towball limit which is towing a caravan with a 100 kg chassis limit really shouldn’t be having any stability issues on that count. Bigger isn’t always better.

The 7% upper guide links to what a lot of car makers set their car’s towing limit at.

 

[Buckman]

The 7% upper guide links to what a lot of car makers set their car’s towing limit at.

I thought the 5-7% guideline figure was one offered up by caravan manufacturers i.e. Swift?

 

[otherclive]

I haven’t a clue where the figures came from. But in a recent post discussing University of Bath research Prof John mentioned to a question re BMW 3 series Touring that at 1800kg towing spec BMW had matched it to 4% which gave the cars 75 kg noseweight specification the lower bound noseweight.

 

[RogerL]

I haven’t a clue where the figures came from. But in a recent post discussing University of Bath research Prof John mentioned to a question re BMW 3 series Touring that at 1800kg towing spec BMW had matched it to 4% which gave the cars 75 kg noseweight specification the lower bound noseweight.

There's an EU requirement, carried forward into UK law, that the car's noseweight limit must be a MINIMUM of 4% of the car's towing limit.

 

[otherclive]

There's an EU requirement, carried forward into UK law, that the car's noseweight limit must be a MINIMUM of 4% of the car's towing limit.

Yes I was aware of the 4%/25kg range but was picked up recently by mentioning 4-7% range. That’s why I tried to avoid it this time around.

 

[ProfJohnL]

The only correct time to check your caravans nose load is when you are loading the caravan ready to away as how you load a caravan affects its nose load.

Caravan manufacturers are very unlikely to fit a chassis and hitch with a great nose load capacity than is necessary. There are two reasons for this, firstly is cost, but secondly most caravanners tow vehicles have ball S values of 85kg or less and very few have ball capacities in excess of 100kg, so there is little point in fitting higher rated hitches especially to smaller caravans.

Whilst there is little doubt that insufficient nose load has a detrimental effect on towing stability, which leads to the concept that more must be better, there is also little point exceeding the nose load that confers stable towing, and of course you should not exceed the manufacturer's limits.

It should be understood that when towing the forces acting through the tow ball and tow bar will vary considerably. Shock load such as driving over a pothole can create peak forces many times greater than the static loads, so the tow bar has to be strong enough to handle these. However it must also be realised that the applied load is is proportional to the acceleration x the mass involved, and results from towing tests have shown that shock loads transmitted to the tow ball can typically be 3 to 4G (x the acceleration due to gravity) and on rare occasions 7 to 8G meaning if you have a nose load of 70kgf the nose load cand rise to typically 280kgf or possibly as high a 560kgf!

Don't worry because car manufacturers are fully aware of these sorts of effects. However becasue the the applied force is proportional to the acceleration, if for any reason you have set up an over loaded static nose load, that overload is also magnified by the shock accelerations, and that will exceed the designed load safety margins, it will certainly increase wear and tear. It will stress components, it might cause deformation, or even breakage.

Do not exceed manufacturers stated limits for nose load.

 

[RogerL]

The only correct time to check your caravans nose load is when you are loading the caravan ready to away as how you load a caravan affects its nose load.

It's also useful to know what the unladen noseweight is - for those trips to/from the dealership for servicing and/or warranty work.

 

[Marky 1971]

Thanks to all who have replied. I have checked the weight with my bathroom scales. They are a good
set and I weigh the same on them as an extremely accurate calibrated set at work. The cheap kampa gauge reads about 95kgs and is consistent with this reading. The bathroom scales read ( with 3 measurements) 89.4, 89.5 then 89.4 again. I would
tend to trust that this figure is accurate. I feel a little better about this as I only need to get the loaded weight below 85kgs. Thanks again.

 

[otherclive]

Thanks to all who have replied. I have checked the weight with my bathroom scales. They are a good
set and I weigh the same on them as an extremely accurate calibrated set at work. The cheap kampa gauge reads about 95kgs and is consistent with this reading. The bathroom scales read ( with 3 measurements) 89.4, 89.5 then 89.4 again. I would
tend to trust that this figure is accurate. I feel a little better about this as I only need to get the loaded weight below 85kgs. Thanks again.

You have “calibrated” your Kampa gauge now for future measurements at home or away.

 

[Buckman]

There's an EU requirement, carried forward into UK law, that the car's noseweight limit must be a MINIMUM of 4% of the car's towing limit.

Interesting as never come across that previously. Any idea how is a car's nose weight measured? I think the CC used to publish car nose weights at some point, but no longer.

 

[RogerL]

Interesting as never come across that previously. Any idea how is a car's nose weight measured? I think the CC used to publish car nose weights at some point, but no longer.

A car's noseweight limit is down to a number of engineering factors, including the leverage effect on the suspension and the strength of the rear structure

 

[otherclive]

Interesting as never come across that previously. Any idea how is a car's nose weight measured? I think the CC used to publish car nose weights at some point, but no longer.

It doesn’t have to be measured it’s specified by the car manufacturer and the trailer would be measured. The CMHC still produce a list.

https://www.caravanclub.co.uk/globa...ce-and-training/noseweight-specifications.pdf

 

[ProfJohnL]

It all stems from the car manufacture deciding to type approve the particular model for towing.

By a combination of tests and calculations they will establish

1. What the cars GVW and front and rear axle limits are
2. What the cars maximum towed weight limit will be
3. and by calculation what the cars minimum vertical static nose load (S value) can be :- 25kg or 4% of maximum towed weight which ever is greater.

 

[Buckman]

In my owner's manual it refers to tongue weight on towball probably because rthe term nose weight would be incorrect?

 

[otherclive]

In my owner's manual it refers to tongue weight on towball probably because rthe term nose weight would be incorrect?

It’s an American car, so I guess that it still uses American terminology.

Mine being Japanese just says “ towball vertical load”

 

[ProfJohnL]

Until there is a change to the UK regulations concerning car manufacture the official EU description and definition is the S value.

S = the static vertical load S in kg is the proportion of the mass of
the centre axle trailer exerted under static conditions at the
coupling point,

Scientifically it is a "Nose load" not a "nose weight" but like so many vehicle related matters through common mis-suse the wrong descriptors have become common place, Just another example of where "common " is applied its technically wrong.