Noseweight Confusion Again

[Morganic]

I am still confused about nosewights.I am a bit slow so perhaps I am missing something!!
The CC in their leaflet on the subject state-"A recommended noseweight for towing stability is generally in the region of 5% to 7% of the caravan's actual laden weight (usually between 70kg and 100kg)"
What does this mean ? My caravan when fully laden (550kgs empty +250 kgs load) weighs 800 kgs). So using this formula would come out with a nose weight of 56kgs. But is this correct?
My car has nosewight of 75kgs. What nosewight should I be aimiing for?

 

[Lutz]

The 5% or 7% formula originated at a time when caravans were, on the whole, lighter and there were no noseweight limits specified by the manufacturers. Today it has become increasingly difficult to maintain 7% without exceeding these limits (although that doesn't appear to apply in your particular case). That's why it's usually best to make full use of the specified limits, but taking care not to exceed them. The legal minimum is 4%.

 

[lishka]

The 5% or 7% formula originated at a time when caravans were, on the whole, lighter and there were no noseweight limits specified by the manufacturers. Today it has become increasingly difficult to maintain 7% without exceeding these limits (although that doesn't appear to apply in your particular case). That's why it's usually best to make full use of the specified limits, but taking care not to exceed them. The legal minimum is 4%.

Does the noseweight really matter?
I must admit in the last 8 years of towing I have never ever checked or known my noseweight, maybe i've just been fortunate?

 

[Damian]

YES it matters very much.
Your tow car has a maximum weight which can be placed on the towball (that figure is listed in your vehicle handbook) and the caravan has a maximum weight which can be exerted on the towing hitch, which for most vans is 100kg.

Exceed those limits and you are illegal and any problems resulting as a consequence of overloading will invalidate your insurance, warranty and if checked by VOSA will result in your outfit being impounded until the weights are corrected, plus fines etc.

 

[Gagakev]

YES it matters very much.

Exceed those limits and you are illegal and any problems resulting as a consequence of overloading will invalidate your insurance, warranty and if checked by VOSA will result in your outfit being impounded until the weights are corrected, plus fines etc.

Just a thought, has anyone heard of anyone actually being fined for incorrect nose weights?
By the way I do check mine on a regular basis.

 

[Damian]

Yes, VOSA carry out quite regular vehicle checks , particularly on Motorways, and have impounded and fined quite a few outfit drivers, and made them discard items to achieve th ecorrect weight ration before being allowed to continue.
In some instances the van has had to be recovered by flat bed lorry if the towcar is unsuitable (and at the owners cost).

There is usually a write up of the results in the club magazines and PC etc.

 

[Gagakev]

Thanks Damien, I was just curious, glad I do mine regular.

 

[Cockovan]

For Lutz,
I'd be interested where your 'legal minimum' of 4% comes from. I can find no such minimum in technical data or on web sites I have visited over many years of caravanning.

 

[Lutz]

Hi Cockovan,
Various UK Motor Vehicle (Construction and Use) Regulations (2001 was the last edition that I could find) reference EU Directive 95/48/EC which in turn, in Annex II paragraph 3.3.2. states, quote:
The technically permissible static vertical load on the coupling device is that stated by the manufacturer; this load must be not less than 4% of the maximum permissible towable mass and not less than 25 kg. The manufacturer must specify in the owner’s manual the maximum permissible static vertical load on the coupling device, the mounting points of the coupling device on the motor vehicle and the maximum permissible overhang of the coupling device.

 

[Cockovan]

Hi Lutz,
Thanks for the info, but the way I read that is that the vehicle has to be capable of taking a noseweight not less than 4% of the vehicle maximum permisable towable mass, not that the trailer has to exert at least that figure.

 

[Lutz]

You may be correct although it seems to be interpreted by many to refer to the load that the trailer has to exert. In the case this should become an issue of controversy one would have to leave it to the courts to clarify.

 

[ProfJohnL]

Cockovan has made an interesting observation.

The first part states:-

• "The technically permissible static vertical load on the coupling device is that stated by the manufacturer;"

The coupling device has two parts, the ball and the cup, so the way this first phrase is worded it does not differentiate between either part. But the next part states:-

• "this load must be not less than 4% of the maximum permissible towable mass and not less than 25kg"

and the last part states:-

• "The manufacturer must specify in the owner’s manual the maximum permissible static vertical load on the coupling device, the mounting points of the coupling device on the motor vehicle and the maximum permissible overhang of the coupling device."

Only the tow vehicle has a "maximum permissible towable mass" and the use of the words "Motor vehicle" clearly excludes the trailer which is not a "motor" vehicle. so the relevance of the regulation must be seen as pointing to the tow vehicle.

This therefore is telling tow vehicle manufactures that the tow ball (and sub frames) must be capable of being loaded to a minimum 4% of the MPTM.

To put this into figures some large 4x4s are rated to tow upto 3500Kg this means the tow ball must be rated to at least 3500x4% = 140Kg

At the other end of the spectrum, the regulation is telling tow vehicle manufactures that don't bother fitting a tow ball that is rated any less than 25Kg - however the converse does not mean that the MPTM of the vehicle has to be a minimum of 625kg (100x25/4). The motor manufacture can set what ever limit they determine as a result of testing.

Even though this particular regulation does not set a minimum value of nose load for an outfit, There is plenty of evidence that points to the need for an adequate nose load to aid stability. To this end it is wise to use a high percentage of the available StaticVertical Hitch Load capacity of the tow vehicle, provided it does not exceed the hitch load limit of the trailer.

As a guide the Caravan Club do suggest aiming for a nose load of between 5 and 7% of the trailers MTPLM, providing it does not exceed the limits of the car or trailer hitch.

As ever good towing is about keeping the range of criteria that affect towing in balance and not just focusing on one factor such as nose load in isolation.