Monday 23 April 2012

Extreme Tyres. Car Tyres And More, Small And Large

Sometimes, size is all that matters. It's important when choosing car tyres to select ones that are the right size. However, if you think the 205/45 x 17 tyres on your Mini Cooper S are rather special, stand by to be amazed, and not a little outclassed.

In this instance, 205 millimetres equates to 8.07 inches. These car tyres may look wide on a Cooper S but in reality, they aren't much to write home about. The world's widest car tyre, on the other hand, is worth describing in a letter. The Pirelli P Zero Nero 405/25 ZR 24 is an asymmetric car tyre aimed at 'tuners and the most demanding sports performance drivers'. With a 25% aspect ratio, as the numbers say, this car tyre is bound to look wide. With a width of nearly sixteen inches, it is wide – extremely wide. In fact, the widest car tyre on Pirelli's website is a mere 315 section item, which equates to a comparatively paltry 12.4 inches. That said, the web reports a Chevrolet Corvette special sitting on 405-section tyres, on 24 x 15-inch wheels…and there are pictures to prove it.

To go still bigger as regards tyres, we must move out of the realm of car tyres. Bridgestone used to hold the record for making the world's largest production tyre, with its 59/80R63 V-Steel E-Lug S tyre. Fitted to earthmovers such as the Caterpillar 797B and 797F, these tyres stand 4.02 metres high – that's a little under thirteen and a quarter feet. Each earthmover wears six of these tyres.

Feeling your car tyres are a little underwhelming sizewise? There's more to come. The 63-inch OTR (Off-The-Road) tyres made by Titan are nearly fourteen feet tall and weigh a staggering 12,500 pounds apiece. Each tyre has a nominal load rating of a whopping 101 tonnes. Just don't expect your trusty tyre fitter to stock these 57.9 inch-wide Titan 59/80R63 tyres. Their size and their 5.66 tonne weight means the tyre racks probably won't cope.

Now that you're feeling distinctly ill-equipped with your pathetic little car tyres, the balance can be redressed with the aid of the 'Wind-Up'. This, the world's smallest road legal car, was built by British inventor Perry Watkins. Being a tiny car, the Wind-Up has tiny car tyres, which we'll come to in a moment.

Let's first see the vital statistics that demand such tiny car tyres. The Wind-Up is 41 inches tall, 51 inches long and 26 inches wide. Its Shanghai Shenke quad bike chassis is powered by a 150cc engine with continuously variable transmission. This gives the Wind-Up a top speed of 40mph, and a frugal thirst – it takes 70 miles to sip a gallon of fuel.

The Wind-Up's tyres come from small motorbikes. At the rear, it wears the wheels and tyres from a Honda Monkey Bike, the tyres being dinky 3.5 x 8-inch items. At the front, the Wind-Up rides on tyres from a 1939 Brockhouse Corgi paratrooper’s mini motorcycle, also 8-inch items.

Should you encounter a set of the miniscule car tyres that support the Wind-Up, there may be something more than a little familiar about the vehicle. Its 31.4 cubic foot body was sourced from a coin-operated ride favoured by little kids. Yes, Postman Pat's van got a new lease of life, courtesy of Perry Watkins.

Article Resource

Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.

The Point Of No Return. Why Car Tyres Fail

Car tyres can fail for a variety of reasons. Some are more common than others but all are avoidable with a little foresight. So, let's look at some problems that can cause tyre failure, and learn how to avoid them.

Underinflation

Running your car tyres at too low a pressure has an immediate penalty. Underinflated tyres have higher rolling resistance than tyres running at the correct pressure. This means you waste fuel on pushing the tyres along the road. A less immediate but more punishing penalty comes from the same lack of pounds per square inch of air pressure inside the car tyre. Put simply, underinflated tyres can overheat. If the tyres overheat enough, it's bye-bye tread or tyre carcass – i.e. it's blowout time.
Inflating your car tyres correctly, to the pressure the car and/or tyre manufacturer recommends, is simple enough, and far less costly than new tyres or a spectacular blowout.

Overinflation

Given the above, it may seem logical to run your car tyres at a pressure higher than the one recommended. Wrong! Tyres running at too high a pressure lose compliance. Meaning? They can't cope well with road irregularities and will be more easily damaged. Such damage can occur deep within the tyre carcass and lead to a dramatic high-speed failure. Once again, the solution is to keep your tyres inflated to the correct pressure.

Excessive Speed

If you've saved a few pounds by buying car tyres that are under specified for your car's capabilities, there's no profit in preening yourself about it. Car tyres have a speed rating, denoted by a letter on the sidewall, for a reason. More highly-rated tyres have superior internal structures and can lose heat more efficiently than lesser items.
While your insurance company will take a very dim view of your running on inappropriate tyres, worse things can happen. Under specified tyres can fail, especially in hot conditions.
A good tyre bay will advise you on which speed rating is right for your car. Take the advice: always buy the right tyres.

Overloading

Car tyres carry a load rating as well as a speed rating and this too is with good reason. While overloading may not often affect passenger cars (except perhaps those used for towing), bigger vehicles can be seen wearing underrated tyres. This goes for 4x4s as well as pick up trucks and small to medium-sized vans.
Once again, a tyre bay is the source of knowledge – if in doubt, have your current tyres checked.

Road Hazards

Which road hazards? Good question, given the road offers plenty of hazards. Those particularly affecting car tyre integrity are pot holes, debris and kerbs. Hit any of these with any severity and you may damage a wheel, as well as a tyre. However, impact damage, even at parking speeds, can wreak unseen havoc within a car tyre.
When checking your car tyre pressures, look out for cuts, lumps and bulges – all can be harbingers of structural disaster in a tyre.

Excessive Wear

In these financially demanding times, it's understandable for drivers to try wringing the maximum life out of their car tyres. That said, taking a car tyre down to, or even past, the tread wear indicators moulded into its treads is false economy, not to mention dangerous.
This is another thing to check when you get down and personal with your car tyres. Remember that well worn tyres can lack structural strength as well as grip.

Article Resource

Merityre.co.uk are one of the leading UK independent suppliers of car tyres. Why not visit their website for an online tyre quote or contact your nearest fitting centre.