Message Forums

Hi,

It is difficult to guess, dependent on tyre construction. Maybe between 50 and 65psi.

Mr UM

Hi

As said it depends on the tyre's construction and MPTLM (maximum loaded weight) of the caravan.

Years ago some caravans around 900kgs were fitted with ordinary car tyres.

In my opinion the tyres on your caravan should have a load index of at least 84 or more (maximum weight per tyre of 500kgs). This will give you a reasonable safety factor. 

Need to know the actual tyre size, max pressure and load index to give you the correct pressure.

Tyreman

155/80 r13

max load at 965lbs at 35psi max press

the info was right at the top, pain in the butt trying to see, info same on both tyres.

max load at 965lbs at 35psi max press

According to my workings out , 965lbs x 2 tyres = 1930lbs max load for the axle , converted to Kgs it comes to 875kgs , so if your loading your caravan to 900kgs your actually going over the tyres rating .

atb

Wizard

yeah its weird, caravan instructions is

14.7cwt unladen

17.7cwt fully loaded

calcultions if im right, someone please confirm

14.7*112/2=823kg

17.7*112/2=991

payload=168kg

according to the tyre info as you calculated  875kg tyre max

caravan 991kg, tyres 875kg???????????????

according to the tyre info as you calculated  875kg tyre max

caravan 991kg, tyres 875kg???????????????

875kg is for both tyres , one tyre at 965lbs = 437kg   2 tyres = 875kg

14.7 cwt = 747kgs

17.7 cwt = 899kgs

atb

Wizard

so in theory i could load to the max, which is 128kg, this takes it to the max for the tyres + bonus load.

tbh most of the stuff that will be in the caravan sould be light, bar the awning and gas bottle. 

Hi morphe

To confirm

"Your tyres are unsafe for loads above 875kgs."

Caravan tyres should be renewed every 5 to 7 years regardless of apparent condition. You can check the age by the reference number at the end of the DOT code. If the last 4 numbers are 0604 it means the tyres were manufactured in week 6 of 2004. If your last 4 numbers cannot be identified as since 0100 they are over 7 years old. If this is the case I'd definitely change them.

Gary is correct that around 1990 manufacturers claimed a bonus on caravan tyres of 10%. That was in the days when 50m.p.h. was the limit for towing.

Nowadays they do mostly abide by the 10% safety factor (but regularly deduct the noseweight from the MPTLM before doing the sums). The 10% safety factor is not a legal requirement but is strongly recommended by the tyre manufacturers association and this is endorsed by the Caravan Club.

If you don't accept this recommendation I advise you not to load your caravan above 875kgs and also ensure that neither wheel is overloaded (max. of  437.5kgs) otherwise you'll be breaking the law as well as risking tyre failure.

Tyreman