Archive for the ‘Wheels’ Category
The Most Remarkable And Prominent Tires
The first tires in the history appeared before the creation of a car! In 1845 an Englishman Thompson patented an amazing invention – leather wheel boots that were able to cushion shaking carriages. Inside it contained tensile rubber belts and was attached to rims with the help of 70 strings.
The tires by Thomson were showed and tested at the London Industrial Exhibition in 1846 – the testers said that the riding became much more comfortable.
The first pneumatic tires were produced by Michelin and mounted on Peugeout of 1884 with a 4h.p. engine. This car took part in the racing Paris – Bordeaux during which the tires had to be replaced 22 times. Nevertheless Peugeot took the ninth place (out of nineteen participants).
The biggest tire in the world is Bridgestone 59/80 R63 V-Steel E/Lug S and Michelin 59/80 R63 XDR intended for mine dump trucks with the carrying capacity of 380-400 tons. The dimensions of the tires impress – the height of the Bridgestone giant is 4,37 yards, diameter – 1,65 yards, weight – 5,1 tons.
The smallest tires can be found on the micromodel by “Nippondenso” - the acting copy of Toyota AA sedan of 1936. The tiny car is equipped electric engine and has the length of 0,1 inches, the wheel diameter is approximately 0,03 inches.
The most expensive serial tire is Pirelli Scorpion Zero 345/60R17 with V speed rating letter (up to 150mph) that was initially designed for Lamborghini LM002 crossover. Their price is around $900 for one tire. Michelin Pilot Sport takes the first place among more mass tires for common passenger cars. Its size is 225/45R18, Y speed rating letter, price – $600.
The most high-speed tire certified for street use is Continental ContiSport Contact 2V max intended for the riding at the speed up to 220mph. The base for the production of this flagship tire is well-known ContiSport Contact 2 model that has obtained advanced speed characteristics.
According to the specialists and different kinds of tests, Yokohama AVS can be called the most noiseless tire. Such tires as Pirelli P6 and Goodyear Eagle NCT-5 also provide exceptional level of acoustic comfort.
The most ecological tires are manufactured by the Nokian company. The tire has completely excluded from the rubber compounds of its products such typical component as polyaromatic compound that has proved to be harmful for the environment. Instead of it Nokian uses compounds on the base of harmless rape oil. Such approach does not diminish driving performance of the tires. On the contrary, it allows to achieve lower rolling resistance level and improved traction.
The most low-profile tires were demonstrated by Dunlop (305/25-ZR20 for rear axle and 265/30-ZR20 for front axle). Its close competitors is Continental 2Vmax (235/30 ZR 20 and 305/25 ZR 20) that has been used for the equipment of Porsche Boxster by Techart. Pirelli also offers such models as Pzero DIrezionale and Pzero Assimetrico (355/25 R19 and 345/25 R20).
The most futuristic tires have been offered by Michelin. The wheels have got the name Tweel and have nothing to do with common tires. They resemble bicycle tires and represent dimensional design made fully from rubber in which tensile spokes are attached to tensile rim. The wheels have already been tested on Audi A4 and the results are very promising.
Which Tread Pattern: Directional Or Asymmetric?
There are three main types of tread patterns: symmetric, asymmetric and directional.
Lately the tires with asymmetric and directional tread patterns have been applied more often, especially on expensive models. It is connected with better performance of the tires if to compare with symmetric tread pattern. Such tires also ensure better withdrawal of water and snow from the contact patch without sacrificing (in some cases even with improving) other parameters.
Tires with directional tread pattern:
Attention! The tire with a directional tread pattern must be rotating only in the direction pointed by the arrow that is located on the sidewall. Incorrect mounting can lead to considerable worsening of steering control and quicker wear of the tire.
Directional tires show exceptional performance. The only disadvantage of such tire is the impossibility of remounting from the left to the right side. How to mount a spare tire on a wheel? – You’ll never know which tire will be punctured!
Recommendations: It is better to have a spare wheel with a symmetric tread pattern as it is universal. And if the tread pattern is directional it is better to mount the tire on the wheel at the right side. According to statistics, right wheels are exposed to punctures and damages to a greater extent than left wheels.
Tires with asymmetric tread pattern:
Attention! A tire with an asymmetric tread pattern is to be mounted only with the “OUT Side” sign located at the outer side of a vehicle and “IN Side” – at the inner side. The incorrect mounting can lead to considerable worsening of the steering control and quicker treadwear.
The tires show very good performance and don’t have ”spare wheel problem” as their outer side always remain outer.
Tires with symmetric pattern:
Symmetric tires have good performance while possessing one serious advantage – excellent price-quality ratio. For many drivers this characteristic is the most vital as not all people need super performance at high speeds.
Choice Of Tires. Recommendations.
Which tires to buy? Wider or narrower? Higher or lower? The manufacturer recommends tires of different sizes for the same vehicle. It depends on:
• what wheels are mounted on your car – steel or alloy (alloy wheels usually have bigger radius).
• for which season the given tire is used – winter or summer.
• what is the power of the engine mounted on your car.
We recommend to choose tires from those sizes that are recommended by the manufacturer of your car.
Attention! Non-observance of these recommendations can lead to the worsening of the steering, distortion of speedometer indications as well as the damage to your tires!
When mounting tires with the width or height that exceed the recommended they can (especially when cornering) rub against the stationary body parts or suspension components.
Mounting tires with lower width or height can lead to the increased rigidness, increased probability of wheel damage. The loading on all components of suspension and bearings will also rise.
When choosing tires from the recommended sizes one should be guided by the following tips:
Wider tire:
+
• larger contact patch
• better acceleration and braking performance (especially powerful cars)
• better cornering at high speed
-
• price rise
• weight rise (most notable when the engine volume is small: 1.4 – 1.6)
• slight fuel consumption rise
• increased hydroplaning effect (a vehicle loses steering when in slush or puddle)
Here the choice depends on your personal preferences and financial possibilities. As a rule, more powerful and fast cars are to be equipped with wider tires. On the contrary, one should mount narrower tires on the cars with small engine volume.
The choice is yours!
More expensive or cheaper? What is the difference besides the price?
Very often cheap and expensive tires can look alike but it’s not that simple. Expensive tire is manufactured with the use of the newest technologies and materials. Special rubber compound and the newest design are used for the production of such tires.
All this allows to improve the basic characteristics of the tire:
• reduced weight (improved dynamic performance)
• reduced fuel consumption
• considerably reduced mileage
• improved steering, reduced braking performance (it is your safety)
• reduced noise level
That’s what you pay for when buying a more expensive model.
Tires Of The Future
Our futurological forecast will concern present-day technologies that have already “conquered” the global market. Run-flat tires, ecotires, tires with high treadwear resistance level (guaranteed service life exceeds 60 000 miles) are the reality that is available practically at any shop. But in 2010 there have been presented conceptual developments that are intended for the vehicles of 2010-2020ies.
Cyber tires
This development belongs to Pirelli. These cyber tires (that have been previously regarded as consumable materials) will be integrated into the central metering computer system of a vehicle. The sensors located within the wheel transfer information to the on-board computer thanks to which the driver and all cruise-control-like systems obtain all the necessary data: temperature of road surface, its humidity, safe mileage left to the next wheel changing, wheel rotation speed.
Auto-pumping
Pirelli also develops X-Pressure technology: the sensor in the tire informs the driver of the pressure loss, the signal is easily read from the indicator on the nipple cap and the data are transferred to the on-board computer. Safety Wheel System works in a similar way – the tanks with compressed air are located in the wheels, the air is transferred to the tire when necessary.
Airless tires
The first treads were non-pneumatic. Today’s technologies approach the possibility to create “airless” tire of the new generation. The prospective development has been presented by Amerityre company: special design and materials will allow to create tire that will not be “afraid” of punctures while having lower rolling resistance level.
Beyond the horizon
In the more remote future scientists will be able to create “adaptive tires”. Such tires will be able to adapt to changes of road surface by way of molecular restructuring. Another possible technology – “transfer” of voltage directly from the road surface that will allow to manufacture cars and public cars without batteries.
How To Choose Wheels?
The first and the main question – steel or alloy wheels? To answer it correctly You should be aware of “unsprung mass” notion.
Unsprung mass is the mass of the vehicle’s components that are located under the spring (shock absorber strut etc) – i.e. wheels, brake disks or drums, suspension lower control arms and other suspension components that are attached to the lower suspension springs. The other components constitute sprung mass (body, engine etc) as they are located above the springs. What happens when the wheel hits a bump? The whole unsprung mass goes up thus tightening the spring. The bigger the mass the stronger is the impact on the spring and, as a result, on the body of a vehicle. The same happens when the wheel gets into a pit – the unsprung mass stretches the spring thus “dragging” the body. So, lighter cast wheels lower the unsprung mass. On the contrary, heavier steel wheels increase the unsprung mass.
Light alloy wheels ensure higher comfort level and durability of suspension. Alloy wheels provide reinforced stability. Besides this, lighter wheels also ensure reduced fuel consumption level, improved ventilation of brake disks, reinforced cooling of wheel heads what results in the rise of the effectiveness of the braking system. Of course, You shouldn’t forget about the wheel balancing.
It is natural that alloy wheels also contribute to the looks of Your car. Yet, alloy wheels have two serious disadvantages: quite high price and lower durability and repairability (if to compare with steel wheels). If an alloy wheel cracks You will even hardly reach a wheel service center. Steel wheels, however, will allow You to continue a ride.
Conclusions: if You have enough money and You operate Your vehicle in street conditions, alloy wheels are the best option for You. In case the vehicle is operated in off-road conditions, choose steel wheels!