A guide to caravan tyres and wheels
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When it comes to travelling with your caravan, there is little more important when you’re on the road than the wheels and tyres.
They can make all the difference between a dream holiday and a roadside nightmare. While any new or recent caravan will most likely still be wearing the wheels it was supplied with from the factory and, hence, these will be properly specified, an older or secondhand caravan won’t necessarily have the right wheels and tyres fitted.
It’s incumbent on you, the owner and driver, to make sure that the wheels are up to the job in hand and are in tip-top condition.
What are caravan wheels made of?
First things first; the material the wheels are made from. This can either be alloy or steel. Steel wheels are cheap and easy to manufacture and are strong but, because of the manufacturing process, generally are not particularly nice to look at. They will be painted because as we all know, mild steel rusts and wheels are no different.
So steel wheels should be kept in reasonable condition. A little surface rust isn’t a problem but you should check the inside of the wheel rim as well as the outside periodically, to make sure it isn’t hiding any damage, such as dents from rolling over potholes or other road debris.
All about alloy wheels
Alloy wheels are typically formed in aluminium alloy and are usually cast, making them reasonably cheap and easy to manufacture. Some may be described or labelled ‘load rated’ but this actually means very little, as there are no regulations in the UK relating to the weight-bearing capability of an alloy wheel.
The German TÜV regulations, however, do specify that aftermarket alloy wheels must be at least as strong as the original fitment, so if you are looking for replacement wheels, look for TÜV approval. These should also be checked periodically for damage.
Check your tyre age
As most caravans cover much lower mileages than cars, it is likely it will be age, rather than wear, that limits your tyres’ life. Caravan tyres will generally spend most of their time on the ground and out in the sun, both of which can cause issues.
If the caravan is parked for a long time, the tyres can develop flat spots, so moving the caravan from time to time or parking it on curved tyre savers can help prevent this.
The ultraviolet component of sunlight is also a killer for tyres; it hardens and breaks down the rubber and can cause it to crack and fail. An easy way to prevent this is to shield the tyres from the sun where possible. A wheel cover is ideal but even a blanket or a piece of wood is better than nothing.
When it comes to age, the Approved Workshop Scheme recommends no older than seven years from the date of manufacture, though anything up to five years after the manufacturing date is considered ‘new’ by the tyre industry. The British Tyre Manufacturer’s Association (BTMA) recommends changing tyres every five years and never to use a tyre that is more than seven years old.
A word on caravan weights
Tyres on a caravan don’t necessarily have to do the same work that they do on the towcar, but that doesn’t mean they have an easier time. For example, my Adria Adora has a maximum technically permissible laden mass (MTPLM) of 1,400kg.
As a single-axle van, that means each wheel and tyre is supporting a minimum of 700kg – I say minimum because the weight split across the axle won’t always be exactly 50/50, depending on loading, cornering forces, road profile, etc.
Even if the apparent weight on one of those tyres increases by 10%, from the tyres’ perspective, you’re looking at an equivalent four-wheeled vehicle with a weight of just over 3,000kg – that’s an almost-fully-loaded long-wheelbase Transit van or a Ford Mondeo estate, complete with a Focus packed in the boot!
Tyres for this kind of weight are generally made for light commercial applications and are designed with a strong construction and use high pressures, as it is this that supports the weight of the vehicle.
Pressures need to be checked before every journey, as well as while standing unused, as even a small drop in pressure can have a huge effect on safety, stability and potential damage to the tyre.
Caravan tyre checks
Not only is the specification of the tyre crucial, so is its condition. Again, ideally when you check the pressures, you should give the tyre a visual once-over to make sure that there are no signs of damage.
You’re looking for cuts, cracks or bulges in the sidewall, any of which could cause failure when driving and mean that it should be changed.
You’re also looking for anything stuck in the tread that could cause a puncture and, of course, the condition of the tread itself. Tread depth should be the same as the car – 1.6mm across at least 3/4 of the central section of the tread around the whole circumference.
The way the tyre is wearing can give you an insight into what is happening – more wear on the middle of the tread means that it is overinflated (the tread is round rather than flat) whereas wear on the outer edges of the tread means that it is underinflated (it’s running on the outer edges and the centre is not making contact with the road).
Tyre Press Monitoring System
All new cars sold in the UK since 2014 have had to be fitted with a tyre pressure monitoring system (TPMS), which can be very useful to spot a problem early on. Advanced warning of a deflating tyre means you can reduce speed or stop to rectify the problem without getting to the point where the tyre is completely deflated – potentially instantly – and offers almost no control (notwithstanding run-flat design or filler bands).
There is no requirement for caravans to be fitted with this although some manufacturers – Al-Ko and Bailey, for example – are installing it in their chassis. But for owners of older ’vans, aftermarket options are available.
These can either use an internal pressure monitor fitted inside the wheel rim when the tyres are removed or one on the end of the tyre valve to monitor the pressure that way. TyrePal is a good example. The actual pressures are displayed on a screen in the towcar and alarms can be programmed to sound when the pressure drops to a certain level, allowing the driver to stop and investigate.
What to do in an emergency while towing a caravan
Easy to say but if you have a tyre blowout (a sudden loss of air pressure), don’t panic. Depending on whether you have a single or twin-axle ’van, you may have some or little control of the caravan.
Try to bring the outfit to a stop gently and without standing on the brake pedal – this will upset the weight balance even more and put even more stress on the failed tyre. Gently steer to the side of the road and stop in as safe a place as you can.
If you’re on a motorway but cannot get off at the next junction or services, stop on the hard shoulder and get all occupants out of the car out and behind the safety barrier. If you’re on a ‘smart’ motorway, try to make it to a refuge area but, if you can’t, make yourself as visible as possible – with hazard lights and a warning triangle.
In all circumstances on the motorway, call the emergency services from an emergency phone or your mobile and follow their advice – don’t get stuck in to changing the wheel and tyre yourself.
Advice given by consultants and contributors within Caravan is designed to be by way of suggestion only and does not negate a reader’s responsibility to obtain professional advice before acting upon it. Any such advice is not a recommendation on behalf of the Editor or Publisher and is followed entirely at the reader’s own risk. Consequently, the Editor, Consultants and Publisher shall not be responsible for any loss or damage incurred by a reader acting upon such advice.