Brakes

WHEELS AND TYRES

Caravan Road Wheels

This topic should not be a concern if you are purchasing a new caravan. However, some older second hand caravans may be fitted with inappropriate wheels for the load they have to carry. If unsure seek specialist advice and an inspection of the wheel rims prior to purchase of the second hand caravan.

The suitability of a wheel rim for use as a road wheel on a caravan, is not a topic that most caravanners even consider. To most of us a wheel is a wheel, and the main things that are generally checked on a replacement wheel are:

the wheel stud pattern matching that on the axle hub;

whether it is bent, buckled, or running eccentric, and it is not rusted.

Not being experts, we never know if it will accommodate the wheel load and the road speed requirements of today.

Years ago when caravans were generally lighter, and not required to achieve the road speeds of today, passenger car wheels of the appropriate diameter and wheel stud pattern, were generally quite acceptable as caravan road wheels. Nowadays thankfully, all new caravans are fitted with wheel rims that are specially designed for the greater loads and stresses put on caravan road wheels.

Caravan Road Tyres

A lot has been written about caravan tyres and, I dare say it will be an ongoing subject. Whilst they are readily visible, caravan tyres are generally taken for granted until your first tyre failure out on the road. Yes, and our friend Murphy sees that caravan tyre failures always occur at the most inconvenient time and place. When you consider that the load per wheel, on a caravan wheel and tyre, is generally far greater than the load per wheel and tyre on a normal passenger vehicle, then caravan wheels, and especially tyres, are working very hard. It therefore follows that only the best quality heavy duty tyres should be used on caravan road wheels.

Remember, all road tyres have a dynamic factor for a given tyre diameter. That is a given tyre diameter is speed and load limited. What that means is that if you increase the load on the wheel/tyre, you must correspondingly decrease the road speed of that wheel/tyre. Conversely, If you wish to travel faster, you must lighten the load on each wheel/tyre.

The age of a tyre is another very important factor that should be considered when talking caravan tyres. This can result in what I call “The Seven Year Tyre Itch”, for want of a better title. Some brands of tyres have a bad habit of failing on caravan wheels around seven years of age. I shall not mention any brand names, and the circumstances of the failures are so many and varied, it cannot be attributed to any particular brand of tyre. I would suspect however, these failures have a lot to do with a combination of heavy loads, travelling too fast, incorrect tyre pressures, coupled with ultra violet ray damage on unprotected tyres, when the caravan is parked. So be warned, most brands of tyres are unreliable around that age and I suggest you budget for replacement caravan tyres every six to seven years.

The best road tyres on the market today, for use on caravan wheels, are what are called “Light Truck Radial Tyres”. As their name implies they are meant for use on light trucks and heavy duty operation. They are readily available from all good tyre dealers and, I would recommend you request your tyre dealer to undertake the following for you, when you take your caravan in for replacement tyres;

provide the actual tyre manufacturer’s recommended dynamic [i.e. max Load & Speed rating] for the tyre they are proposing to fit to your caravan road wheels;

the maximum tyre pressure that should be used with these tyres for your caravan wheels;

have them fit the identical tyre to your spare wheel/s, and

provide a recommendation for tyre rotation frequency, to ensure all tyres including the spare wheel/s have equal use.

Tyre Protection from the Sun Ultra violet rays from the sun can be very harmful to all tyres and especially caravan tyres, when you consider the long time caravans spend parked out in the sunlight. When not in use your caravan tyres should be shielded from direct sunlight, by materials that ultra violet rays cannot readily penetrate. A piece of thin timber or fibreboard between each wheel arch and the wheel, or wheels, will be adequate. It is also very important that externally mounted spare wheels are also covered. Most automotive accessory outlets sell relatively cheep vinyl wheel covers that will cater for this requirement.