Do you pay sufficient attention to the condition of your motorhome's tyres?
Are you sure? After all, a tyre blow-out at speed will, at the very least, cause the vehicle to become dangerously unstable. And, at motorway speeds,
it could even end up falling onto its side – if it does, you will be seriously injured. Perhaps even killed. Understanding more about your tyres and what problems to look out for could save you the hassle of a puncture and even save your life.
The amount of tyre distortion is calculated when suspension settings are calibrated, so those that are not working correctly can cause unpredictable vehicle handling and impaired ride quality. More importantly,
a damaged or deteriorating tyre could fail
The law
The law states that tyres on the same axle must be of the same type and size. But type doesn't mean manufacturer or model. It means the way it was manufactured.
For instance, if the nearside tyre is an eight-ply Michelin XC radial of 215/75/16 size, the one on the offside must also be an eight-ply radial of 215/75/16 – the manufacturer of the tyre is irrelevant.
Fitting a seven-ply radial with an eight-ply radial would be against the law, as would fitting one old-fashioned cross-ply tyre, with a radial on the other side. Fitting different tyre types to the front and rear of a vehicle is also forbidden.
The other legal stipulation regards the amount of tread. European law dictates that there must be a minimum tread depth of 1.6mm across the centre 75 percent of the tyre's width in a continuous band. Our advice? Well, we'd say that if any of the tread is
below 1.6mm, it's time to go shopping. And, if they are to be resold, part-worn tyres must have at least 2mm of tread.
Aside from the fact that having defective tyres can cause an accident, it's also the case that if you get stopped by the police, you could end up with a fine of £2500 and three penalty points on your licence.
Problem areas
While the law is explicit about
tread depth and tyre type, it is fuzzier when it comes to condition. Our advice is that
if your tyres are showing even minor signs of damage, you should get them checked.
There are multiple problems to look out for, but most result in the same outcome - a flat tyre. The most common reasons for a flat are a puncture or a damaged valve. What sort of puncture can be repaired varies from place to place, but as a general rule, any tyre with a puncture within an inch of its sidewall should be considered as scrap. Tyre sidewalls cannot be repaired. Puncture repairs are governed by a European safety standard (BS159F), and a properly repaired puncture is perfectly safe. Tyre fitters to whom we spoke said that repairing punctures on tyres which have fewer than 2mm of tread is frowned upon. Punctures over 6mm diameter are not legally repairable.
Finally, don't be tempted to use tyre repair foam. It is difficult to clean off the wheel rim afterwards, and often a new rim is required.
A damaged valve is another reason for tyres going soft. Sometimes, small bits of
grit can jam the valve open,
or it can just stop working properly. Budget between
£5-£10 for a replacement.
Wheels, too, need to be in good condition. Steel rims, which have been heavily kerbed or are turning rusty, can prevent the tyre from sealing against the rim.
The other thing to be aware of is the age of your tyres. ‘Baxo', our Practical Motorhome project van is 11 years old,
yet has only managed to put 15,000 miles under her wheels. This is pretty typical, but
we had the tyres carefully inspected for age-related damage. The effects of the weather and the weight of the motorhome can lead to them being fit for the bin, despite having plenty of tread left.
Baxo's tyres have been replaced at some time, but not all vans will have been so lucky. Park yours in good light and carefully examine the tyre sidewalls for cracks, typically those going around the tyre. These will be more apparent at the bottom, where the sidewall will be swollen and any cracks wider and more visible.
The other place to inspect is the tread. Cracks can run radially, hidden between the lines of the tread. Such damage can cause a puncture, but it can also cause a rapid loss of air – a blow-out.
Care and attention
Looking after your tyres is easy, but motorcaravanners need to take extra care because their 'vans may not be used every day.
The most crucial item to check is tyre pressure. Information from the Tyre Industry Council suggests 25 percent of vehicles on the road have tyres which are under-inflated by more than ten percent. As well as making your 'van behave badly on the road, it will cause premature and excessive wear, and, in severe cases, failure. Over-inflated tyres can be identified by excess tread worn from the middle of the tyre – this affects handling and will cause tyre failure.
Overloading your motorhome results in similar symptoms to under-inflation. The sidewalls sag and that leads to excess heat build-up, making tyres wear more quickly.
The roads are awash with corrosive salt and other muck which won't do your tyre rubber any good, so it's a good idea to wash your tyres using one of the various tyre cleaning products available.
Finally, the main thing to bear in mind is the relative lack of miles covered by the average motorcaravan. If it is being laid up for the winter, periodically roll it to a new position so that three tonnes of 'van is not resting on the same bits of tyre for four months. That way, you will stop tyre distortion and a subsequently noisy ride. l–
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