They became significantly cheaper (the price difference with the standard bus is about 20%) and almost equal to the usual ones according to the main “driver” characteristics.
An expanded assortment of such tires was recently introduced by Pirelli: its most popular models - Eufori @, P Zero Nero, Winter Snowsport, Winter Sottozero now have “nail-proof” doubles that are almost indistinguishable from the “standard”. But inside they have a whole bunch of patents.
The main achievement is a noticeable reduction in tire weight due to the lightening of the carcass and sidewall. In the Run Flat tire line, Pirelli generally managed to reconcile two polar properties: a rigid sidewall and low rolling resistance - it is almost the same as traditional tires. Accordingly, fuel consumption has hardly changed. A thinner sidewall is also more elastic: it is not enough to perceive the weight of the car itself at rest, it is also necessary to withstand dynamic loads, providing proper traction!
Judging by the test results, the Italians coped with this task successfully. The recommended maximum speed on a flat tire is 80 km / h and a distance of up to 150 km is sufficient not only for Europe but also for Russia (it’s another matter that by European standards our roads are a country side). But - attention: Pirelli recommends not repairing, but replacing tires that have lost pressure - and this is an additional cost.
Today, Pirelli produces nail-resistant tires in more than 30 sizes with a bore diameter of 16 to 20 inches, including for all-terrain vehicles and "charged" cars. Not far off is the further expansion of the range towards more “popular" cars.
DOUBLE BOTTOM WHEEL
Remember the recent scandal in Formula 1 involving the use of a double tank by the BAR team? Is it not at Pirelli that the Anglo-Americans have spied this idea? Just a few months earlier, Italian tire manufacturers presented a simple and elegant solution - the “Safe Wheel System” (SWS) with a double rim.
An annular chamber made in an alloy wheel (photo 1 and fig.) Contains a supply of air under a pressure of about 10 bar. When it falls, its internal chamber valve automatically opens, restoring pressure to normal. If the tire is in good condition, there will be enough compressed air for 9-12 months - this eliminates the need for periodic inflation of tires. By the way, in order not to pump the tire that has cooled down at night or in the cold, a temperature compensator is provided in the valve.
The system also helps with punctures, especially those associated with a sudden loss of pressure. Since this year, the SWS system for off-road vehicles has appeared. It can be used with both conventional and “nail-resistant” tires. The air supply in the rim is easy to replenish at any service station or a major gas station. In the end, you can get by with a good electric pump: 10 bar is an affordable value.
“BLUE TOOTH” VALVE
Despite the fact that the wheels themselves learned to pump up the tires, and they are able to ride with holes, you still need to control the pressure. The Pirelli X-Pressure Tracking System does this from a distance. Its sensor is mounted in the wheel valve, so the type, size and even the tire manufacturer does not play a role here.
There are several warning systems to choose from. The simplest one is visual (photo 3): a white cap on the valve indicates that the pressure is normal, red - the tire needs to be inflated. A more advanced system is a valve with a transmitter: when the pressure drops, the driver hears a sound signal, and information about this is displayed on a separate monitor in the passenger compartment (photo 4). The third option is the popular Bluetooth protocol (“Blue tooth”), which allows you to transfer all data to the owner’s mobile phone (photo 5).
The developers also envisaged the protection of smart gates against thieves. To dismantle the device, you need a special key, and in addition, during the first installation, it recognizes the receiving device and subsequently only works with it.
The idea of humanizing a machine, or at least teaching it to feel, has occupied the minds from time immemorial. The latest Pirelli designs, the Cyber Wheel and Cyber Tire, are another step in that direction. Engineers managed to mount sensors in the wheel and tire that transmit real-time information to the on-board computer about wheel speed, angle of rotation, lateral and vertical accelerations, horizontal rotation, temperature, tire pressure, etc.