Bailey Unicorn - The Caravan to Towing Vehicle Weight Ratio; Kerb Weight of Towing Vehicle; Towing Vehicles Rear Suspension; Recommended Towball Height

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CARAVANANDTOWVEHICLE
When taking the measurement the jockey
wheelshouldberaisedandthecornersteadies
lowereduntiltheyarejustclearoftheground.
KerbWeight:Theweightofthetowingvehicle
asdenedbythevehiclemanufacturer.
Thisisnormally:
•Withafulltankoffuel
•With an adequate supply of other liquids
incidentaltothevehicle’spropulsion
•Withoutanydriversorpassengers
•Without any load except loose tools and
equipment with which the vehicle is
normallyprovided
•Withoutanytowingbracket.
The caravan to towing vehicle weight ratio:
Thiscanbedetermined bycalculationandis
equalto:
Actualladenmassofcaravan
100%
Kerb weight of towing vehicle
Asageneralguide:
• Conventional petrol engines with a
capacity up to approximately 1600cc
petrol or 1800cc diesel should be
adequatefor towinga caravanweighing
around 85% of the kerb weight of the
towingvehicle.
• Above 1600cc petrol or 1800cc diesel
such engines should manage a caravan
weighingupto100%ofthekerbweightof
thetowingvehicleandstillgiveadequate
performance.
Thetowingvehiclemanufacturer’stowinglimit
is,insomecases,lessthanthekerbweight.
Vehicles with automatic transmission may
needanoilcoolerttedortheSAE(Societyof
AutomotiveEngineers) ratingof the gearbox
uid increasing when towing.  The advice of
thevehiclemanufacturershouldbesought.
The law requires that caravans, their towing
vehiclesandthe loadstheycarrymustbein
suchaconditionthatnodangerornuisanceis
caused.(Regulation100oftheRoadVehicles
[ConstructionandUse]Regulations1986.)
Towing Vehicle’s Rear Suspension
It is important thatthe towingvehicle’srear
suspensionisnotdeectedexcessivelybythe
noseweightonthetowball.Ifitisexcessive
thesteeringandstabilitywillbeaffectedand
atnighttheheadlightbeamislikelytodazzle
otherdrivers,whichisillegal.
Thegreaterthetowingvehicle’stailoverhang
(the distance between the rear axle and the
towball) the greater the effect the nose
weightwill have on the towingvehicle’s rear
suspension.
Aftertryingout thecaravanitmaybefound
that stiffening of the rear suspension is
necessary but note that this may give the
towingvehiclearmerridewhennottowing.
There are a number of suspension aids
available and advice should be sought on
whichtouseandhowtot.
It is important to ensurethat the caravan is
towedeitherlevelorslightlynosedown.Ifitis
not,thenthecar’stowbarmaybeatthewrong
height.
Alwaysconsultyourtowvehicle
manufacturerforadviceontowingand
theloadsthatthevehicleiscapableof
towing.
Recommended Towball Height
The recommended towball height for Bailey
caravans is 385 +/- 35mm (350mm to
420mm).
Secondary Braking Cable (breakaway device)
Purpose: To apply a trailer’s brakes if it
becomes separated from its towing vehicle.