The caravan came out of the yard last weekend, the tread looks almost new, and the tyres are eight years old. That combination puts more rigs on the side of the N1 in December than nails do.
Towed tyres fail differently from driven ones. A car's tyres wear out because they work every day. A caravan's tyres age out while standing still, which means the usual glance at the tread tells you almost nothing useful. If you are heading to the coast in December, the checks below are worth an hour in September.
Why caravan tyres age out instead of wearing out
A caravan typically works for two or three weeks a year and stands for the other forty-nine. The tread barely erodes. The rubber, meanwhile, spends those months in Highveld sun and temperature swings, and rubber hardens with time and heat whether or not it turns.
A hardened casing has less give in it. It builds heat faster under load, and heat is what takes tyres apart on a long run at speed with a loaded rig behind you.
So the first check is not tread. It is the date.
The date code, first
Find the DOT code on the sidewall and read the last four digits. Week, then year. A tyre stamped 3219 left the factory in week 32 of 2019. Do this on all the caravan's tyres and on the spare, because they are frequently not the same age.
We wrote the full method, and why it catches people out on car spares too, in the spare tyre problem. On a caravan it is the number that decides most of the other decisions.
Do you need special tyres for a caravan?
You need tyres suited to a towed axle and to the caravan's maximum plated mass, which is not the same requirement as a car's. Many caravans and trailers run tyres with stiffer construction and a load index chosen for standing weight rather than cornering grip. Match what the caravan's handbook and plate specify.
The plate is the thing to find. It is stamped or riveted on the caravan or trailer and gives the maximum mass the unit is permitted to carry. From there, the load index on the sidewall tells you what each tyre is rated to take. That index is a coded number that maps to a weight in tables published by tyre manufacturers, and we explain where it sits in the marking in how to read your tyre sidewall.
Fitting whatever is cheap in that size, without checking the index, is the quiet way to end up under-tyred on the one trip of the year when the unit is fully loaded.
How often should caravan tyres be changed?
By age rather than by tread, and the interval belongs to your caravan handbook and the tyre manufacturer's guidance rather than to a number off the internet. On a vehicle that stands for most of the year, the casing's age is the limiting factor, and tread depth is a poor guide to how much life is left.
Two things move the answer sooner. Standing in direct sun year after year ages rubber faster than standing under cover. So does standing loaded, with the caravan's weight pressing on one patch of each tyre for months.
If you are looking at a set and the date code surprises you, that is the conversation to have with a fitment centre before the trip rather than after it.
Do caravan tyres need to be balanced?
Yes. A towed wheel spins at the same speed as a driven one, and an unbalanced caravan wheel produces exactly the vibration you would expect, felt through the tow hitch rather than through the steering wheel. It is easy to blame the road or the hitch and never look at the wheels.
Have them balanced whenever a tyre is fitted to a rim. We balance every wheel we treat, caravan wheels included, because taking a tyre off a rim and putting it back changes where the weight sits.
Standing, flat spots and slow leaks
A caravan that has been parked in one position for months can come out with the weight-bearing part of each tyre slightly set. You feel it as a vibration in the first kilometres, and mild cases usually settle as the tyre warms and rounds out. Severe flat spotting does not settle, and that tyre needs looking at.
Pressure is the other casualty of standing. Tyres lose air slowly even when nothing is wrong, and over eleven months that adds up to a soft rig. Set the caravan's pressures cold, off the caravan's own plate or handbook, before you load it. Then set the tow vehicle using the loaded figures from its door placard, because a hitched caravan puts extra weight through the rear axle of whatever is pulling it. The whole cold-checking routine is in tyre pressure: the two-minute check.
The spare on the back is usually the oldest tyre you own
It has hung there in the sun since the caravan was new, unpressurised as far as anyone knows, and it is the tyre you would fit at the roadside outside Colesberg. Check its date code, check its pressure, and check that the carrier bolts still undo. Plenty of people discover on the gravel that they do not.
What we can and cannot do for a caravan tyre
Our Nano Polymer coating is applied to the inside of the tread and cures there. On a caravan wheel it does the same job it does on a car: in the tread, it seals as it happens, and in most cases you can keep rolling to somewhere safe. That is worth something on a rig you cannot easily jack on a gravel verge.
What it does not do belongs in the same paragraph. It does nothing for a sidewall, nothing for the bead, nothing for impact damage, and nothing about age. A hardened eight-year-old casing is still a hardened eight-year-old casing with a coating inside it. Every tyre is inspected on the way in and on the way out, and damage already present is excluded from the 1.6 Guarantee. If the honest answer on your set is new tyres rather than treatment, we will say so.
The September list, for a December trip
- Date codes on all caravan tyres and the caravan spare
- Sidewalls checked for crazing, cuts and bulges
- Pressures set cold off the caravan plate, spare included
- Tow vehicle set to its loaded placard figures
- Wheels balanced if any tyre has been off a rim
- Spare carrier bolts tested, jack and brace actually present and fitting
Working through that in September leaves time to do something about whatever it turns up. Working through it on the 15th of December does not, which is the only real argument for doing it now.
If you want a set treated before the trip, put the morning in the diary while there is still room to act on whatever the checks turn up. Send a photograph of the tread, sidewall and date code to +27 76 089 4066 and we will tell you what we would do with the set, or book the morning on the booking page.