NOSEWEIGHT This leaflet is prepared as a Club service. The contents are believed correct at the date of publication but please raise any queries with the Club’s Information office. February 2013 Static Vertical Load or noseweight is the downward force (or weight) of the caravan’s coupling head on a car’s towball. It is vital to have sufficient noseweight when the outfit is stationary, as research shows that the download decreases with speed due to aerodynamic effects on the caravan. If all your noseweight effects are lost at speed, caravan instability is much more likely. Car manufacturers quote a maximum permitted noseweight for each car model. EC Directive 95/48, sometimes referred to as the ‘Masses and Dimensions Directive’, states that this load must be not less than 4% of the maximum permissible towable mass (i.e. the towing limit) and not less than 25kg. Most car manufacturers are a little more generous than this, and they must specify the noseweight in the owner’s handbook, along with the vehicle mounting points of the coupling device and its maximum permissible overhang. Several factors may be taken into account when specifying this noseweight figure, including the capabilities of the car's suspension, the effects on the vehicles steering and its traction (particularly if front-wheel drive) and the strength of the towbar and its mounting. Therefore, it is important not to exceed the car manufacturer’s recommended noseweight. However, from the towing point of view, the higher the noseweight, the better the stability. 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). Maximum noseweights of 70kg or less will restrict the choice of ideally compatible caravan quite considerably. Refer to the tables from page 4 onwards for car noseweights, but check again before you buy, as these figures are liable to change. If the car dealer seems unsure, ask him to find out! Noseweight Nose Weight Static Vertical Coupling Load Towball Down Load Hitch Limit Tongue Load Tongue Weight ‘S’ Value All alternative names for the same thing – your car handbook may use any of these
Transcript
NOSEWEIGHT
This leaflet is prepared as a Club service. The contents are believed correct at the date of publication but please
raise any queries with the Club’s Information office.
February 2013
Static Vertical Load or noseweight is the
downward force (or weight) of the
caravan’s coupling head on a car’s towball.
It is vital to have sufficient noseweight
when the outfit is stationary, as research
shows that the download decreases with
speed due to aerodynamic effects on the
caravan. If all your noseweight effects are
lost at speed, caravan instability is much
more likely.
Car manufacturers quote a maximum
permitted noseweight for each car model.
EC Directive 95/48, sometimes referred to
as the ‘Masses and Dimensions Directive’,
states that this load must be not less than
4% of the maximum permissible towable
mass (i.e. the towing limit) and not less than
25kg. Most car manufacturers are a little
more generous than this, and they must
specify the noseweight in the owner’s
handbook, along with the vehicle mounting
points of the coupling device and its
maximum permissible overhang. Several factors may be taken into account when specifying
this noseweight figure, including the capabilities of the car's suspension, the effects on the
vehicles steering and its traction (particularly if front-wheel drive) and the strength of the
towbar and its mounting. Therefore, it is important not to exceed the car manufacturer’s
recommended noseweight. However, from the towing point of view, the higher the noseweight,
the better the stability.
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). Maximum
noseweights of 70kg or less will restrict the
choice of ideally compatible caravan quite
considerably. Refer to the tables from page 4
onwards for car noseweights, but check again
before you buy, as these figures are liable to
change. If the car dealer seems unsure, ask
him to find out!
Noseweight
Nose Weight
Static Vertical Coupling Load
Towball Down Load
Hitch Limit
Tongue Load
Tongue Weight
‘S’ Value
All alternative names for the same thing –
your car handbook may use any of these
2
Some components have noseweight limits
too, notably the towbar and the caravan’s
coupling. Both are likely to be marked
with an ‘S-value’ figure found on their
respective specification plates. The
towbar S-value can sometimes be higher
than the car’s noseweight limit – usually
because the towing bracket can be fitted
to several models of car, which may have
varying noseweight limits. Most modern
caravans have a coupling S-value of
100kg, but do check for lower limits. For
any given combination of car, towbar and
caravan, it is the always the lowest of the
various figures which must be used as
your outfit’s maximum limit.
If your caravan’s noseweight is too low, it is often possible to adjust where payload is placed
inside the caravan (or front locker perhaps) to give a more forward weight bias. Make sure that
heavy items like awnings are not able to slide around, as this will alter the balance (rubberised
non-slip mats are a good technique). On the other hand, if your caravan’s noseweight is too
high, avoid the potentially dangerous practice of loading heavy items at the rear of the caravan
to reduce it, as this will significantly increase the likelihood of instability. Instead, look to
move heavy items to just behind the caravan axle, or remove payload from the front of the
caravan entirely.
You may need to consider an underslung carrier for the caravan spare wheel instead of front
locker storage, and you might need to see if a smaller and/or lighter gas bottle is viable.
Sometimes, relocating items of payload to the towcar can help, but make sure you don’t
overload the car instead!
It is probably fair to say that noseweight
compatibility is the most common reason for
The Club to consider a member’s proposed
outfit to be ‘not ideal’. This has been
exacerbated by the trend in recent years for
caravans to get heavier, while car
noseweight limits have not increased. Some
owners find it difficult, if not impossible, to
meet the target noseweight recommendation
as a result. While some compromise of this
issue is possible if other factors are
favourable (e.g. outfit weight ratio), it must
be recognised that the risk of instability at
higher speeds will be increased with any
significant deviation from the recommended
values. To keep your outfit safe and
comfortable to tow, it really is worth paying
attention to noseweight both before purchase
and during ownership.
Noseweight is important for twin axle
caravans too. However, it is quite likely with
heavier models you would not be able to
achieve the same noseweight load percentage
as for a similarly sized single axle model,
without overloading the caravan’s front axle
or its tyres.
The additional support from the second axle
means you would need more forward bias of
the payload to increase the noseweight. A
significant load imbalance between the front
and rear caravan axles is probably more of a
stability concern than a slightly light
noseweight.
Finding towbar S-values can be a tricky
3
A selection of conventional
noseweight gauges Photo: Andy Parkington, Radius
MEASURING NOSEWEIGHT
Noseweight can be measured with a proprietary noseweight gauge, obtainable at caravan
dealers. Follow the maker’s instructions and make sure the gauge is kept in good condition.
Our experience is that noseweight gauges vary widely in quality, in terms of their accuracy,
their reliability over time and their ability to resist overloading. To address this, the Club was
instrumental in the development of a British Standard for noseweight gauges (BS7961).
Gauges marked as compliant with this standard should be accurate, reliable and durable.
Realistically, it should not be necessary to check noseweight every journey if the caravan is
similarly loaded for each trip. However, it is advisable to check it at the start of each holiday,
and essential whenever the car or caravan is changed, or if the caravan is going to be loaded
significantly differently to normal (such as for an especially long trip).
This gauge from Towsure sits on
top of the car’s towball and must
be removed before towing.
An alternative is to integrate the
gauge with the jockey wheel,
like this one from Al-Ko. This
gives a good indicative
noseweight figure every time
the caravan is used, but tends to
be less accurate than a good
conventional gauge
This gauge from Milenco has
BS7961 approval and the maker
will check and recalibrate it
after a specified period of use.
You can also use bathroom scales under the coupling head with a
suitable length of wood between the head and the scales, such
that the caravan floor is horizontal. To spread the load insert a
piece of wood at least 15 cm (6 inches) square between the
length of wood and the scales. It is essential that the surface is
firm and level, the jockey wheel and corner steadies are
slightly raised and the handbrake is fully applied for safety.
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ALFA ROMEO
00800 2532 0000 www.AlfaRomeo.co.uk
MODEL KG
145/146/Spider/GTV 50
147/156/166 60
155 1.8 Twin Spark 90
155 2.0 TS/2.5 V6 95
155 Turbo 4x4 105
164 2.0 Twin Spark 60
164 3.0 V6 65
MiTO – all models 60
AUDI 0800 699888 www.audi.co.uk
MODEL KG MODEL KG
100/200 (2WD) 50 A8 (post 2010) 95
100/200 (4WD) 75 Allroad 95
Quattro/ Cabriolet 50 Avant 75
A1/A3 75 Q3/Q5 5 seat 80
A4/ A5/ A5 Cabriolet 80 Q5 2012 100
A6 Avant & Saloon (pre ‘97) 50 Q7 5 Seat 140
A6 Avant/Quattro & Saloon (post ’97)
85 Q7 6/7 Seat 130
A6 Quattro (pre ‘96) 75 S4 75
A7/S7/Q7 Quattro 85 S5 Coupé 80
A8 (pre 2010) 75 RS4 90
BMW 0800 325 600 www.bmw.co.uk
MODEL KG MODEL KG
1 Series 75 M5 all models ‘10 90
3 Series 75 X1 all models 80
5 Series post ‘99 90 X3 2.0d/3.0d/2.0i pre 2012 80
Although the information is believed to be correct at the date of publication, The Club cannot guarantee accuracy. If in any doubt, the figures should be confirmed with the vehicle manufacturer.
1 Pound = 0.45359237 1 Kilo = 2.204622622 To convert kilograms to pounds multiply by 2.203 e.g. 75kgs x 2.203 = 165lbs
