please Michelin, tell me about your new tires


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A tire is not just a round, black piece of rubber. Plus, Clermont Ferrand engineers like to be reminded that the color is dark gray! But at the same time, the design of a tire uses 200 components divided into large families: 10% metals, 24% natural rubber, 25% synthetic rubber, 7% textiles, 14% additives and 20% reinforcing (mainly carbon black and silica). The properties of each component can also be adjusted to produce a tire that is more or less gripping, more or less durable, more or less energy consuming, and even more or less aesthetic. Michelin develops tires for all types of vehicles, from 2-wheel to airplanes, restrictions and biases are even more variable.

From these materials, the tire is developed according to three main areas of work, which makes it possible to obtain a high-performance tire: first, the structure, in which fabrics and metals are involved. Next, the geometry that concerns the profile of the tire and the design of the tread. And then the chemical composition, specifically in the tread, defines the level of grip and durability. For this last point, elastomers play an important role as they alone make up half the composition of a tire. It all starts with butadiene and styrene, which are monomer-type molecules that bond together by reaction and can form a polymer from the elastomer family. Don’t worry, we won’t go any further in chemistry class.

An elastomer’s area of ​​interest is its flexibility, as the name suggests. The chemist can make it more or less extensible, with a rather slick or rather rough sense of touch to schematize later. Characteristics that go in the direction of low rolling resistance or in the opposite direction of grip on the ground. Let’s take a concrete example with two small balls of different elastomer compositions. One jumps very little, indicating that too much energy is dispersed on the ground at the point of jump. For a tire this feature works in favor of grip. Conversely, the other ball bounces a lot with it’s ability to hold energy. For example, an ideal feature for a bicycle tire that requires little grip and rolling resistance, thereby expending as little energy as boldly possible thanks to the strength of the legs.

Another example is by drawing two samples of elastomers with opposite properties. The first is rough, but flexes easily, has good grip but low durability. The other specimen is almost forever flexible, proof of good longevity, but smooth to the touch, so it is much less sticky. Of course, here are extreme examples.

Car or bike tire options

explanatory photoCredit Photo – Michelin

By changing the properties of these elastomers and other tire components it is possible to create a tailor-made product depending on what it will be mounted on. And it therefore complies with very precise specifications: A sports car tire such as the Pilot Sport 5 must therefore be able to support a load of 500 kg (which, when multiplied by four tyres, corresponds to the total mass of the majority of sports cars). , except large sedans or SUVs). It should be able to deliver its full potential at an average pressure of 2.3 bar and withstand speeds of 50 to 300 km/h (or even a little more). All with a very low camber (or tilt angle, let’s say) of 1 or 2 degrees. The ground contact surface of a car tire is also the largest surface facing 2 wheels. So, for example, the Road 6 motorcycle does not need to support a load of more than 120 to 175 Kg, 2 to 2.9 bar, but also needs to support a load of 50 to 300 km/h. Camber is crucial this time with angles that can reach 55 degrees. Finally, a bicycle tire is even more special. For example, the new evolution of the Power Cup has a load of only 50 kg to support at a high pressure of 8 to 10 bar for a medium speed of 30 to 90 km/h. The maximum camber to be picked up is about 30° lower along the ground contact surface, which is minimized here.

Michelin will then take certain biases to make it more efficient in these constraints by playing on grip, rolling resistance, wear and hardness. For example, this last point has been specifically increased on the PS5 to offer better steering power, which is an advantage when playing in the laces.

A Road 6 doesn’t need a lot of stiffness in its mid-tread. The idea is to slightly squash it somehow, increasing the contact surface, giving more efficiency in braking or traction. At its edges, the stiffness is further reduced to repeatedly increase the contact surface when cornering. Combined with a mild chemical composition, adhesion also increases in the name of safety, which is a top priority for corner grips. On the other hand, rolling resistance is reduced and wear is slightly more significant at the edges than at the centre. A sacrifice is also required to maintain a rounded tire profile as it wears, and to prevent the center lane from becoming “square” if it wears out faster than the edges.

For bicycle tires, that’s another story. The cyclist, on the other hand, needs the lowest possible rolling resistance so as not to waste the efforts of the thighs. In the Power Cup, it is much lower than car or motorcycle tires. Conversely, at the same time, the grip level is much lower. Imagine the cyclist biting the asphalt very effectively while braking, “sunshine” guaranteed. At the angle of the tyre, the grip doesn’t have to be too high either, because with a maximum angle of 30° in the corner, the cyclist doesn’t actually put that much stress on it and there’s a risk of getting it. It’s easy to see this on a stage of the Tour de France, with cyclists working their trajectory to get the lowest possible angle and maintain maximum speed. Either way, the pedals would be a problem if they took too much angle. On the other hand, stiffness is important in a bicycle tire that is by definition very thin. The cyclist needs to feel that he can lean on his tire tightly and, above all, somehow not feel a certain softness, like an under-inflated tire. Wear of a Power Cup is also very low because it should last as long as possible despite its thin rubber. A feature that is easier to install when a grip is not required.

In short, the properties of a tire all have a certain logic: It’s a matter of lowering one slider to allow another to be boosted.

Pilot Sport 5: Do better than the critically acclaimed PS4

explanatory photoCredit Photo – Michelin

Despite this, Michelin is striving to raise the sliders in all areas with the Pilot Sport. For the 5th generation, Bibendum should do even better than the PS4 that has been given away many times. The manufacturer thus increased the sliders slightly for driving pleasure and longevity, while applying the new eco-design methods that the brand loves so much today. Note that in Michelin’s sports range, for example, the Pilot Sport Cup R represents the best tire for track days (before switching to semi-slick or slick tyres), the Pilot Sport 5 is designed for normal daily use. the possibility of random pleasure on a winding road.

Its increased performance is, of course, the result of long research on materials, design and construction, again brought to life by numerous patented technologies. Glossary: ​​Dynamic Response Technology uses a hybrid nylon and aramid belt to increase stiffness while stretching the tire, thus improving response as seen above. Maxtouch Construction increases surface contact with the ground, so water retention or evacuation is more uniform across the width of the tread. The Dual Sport Tread Design refers to the asymmetric tread structure that offers both wet (outside the tooth) and dry (mid and inside) qualities. Groove Clear technology corresponds to these 4 wide grooves that allow maximum water evacuation, the first defense against aquaplaning. Even though all manufacturers have their own patented inventions, the last two technologies mentioned above greatly add to the Pilot Sport’s reputation for performance in the wet.

There is a rather surprising axis of development in today’s tires, and it is especially visible on the PS5: aesthetics. Now the engineers responsible for tire design work with the design teams. The challenge of this collaboration is to create a sense of performance just by looking at them, while retaining all the qualities that make up the reputation of this sporty Michelin tire range. The design of the builds flashes in this direction as a sign of “lightning” efficiency on the PS5. The shapes of this flash of light, or otherwise, a fencer’s inclined position is hardly predictable as it is truly inspiring here. The sidewalls of the tire say even more: Michelin inspired this time with the jacket of the fast black panther, embodied here with a velvety feel to the touch and a distinctive identity feature. A few additional details, such as the checkered patterns, clear up any ambiguity about the PS5’s sporting intentions.

Future development arms

explanatory photoCredit Photo – Michelin

Michelin has already given us an idea about the tire of the future with its Tweel technology, which does not require air pressure. However, this is not the case for now when it comes to high-performance tyres. éIn the short term, the French manufacturer, like the others, is mainly working on eco-design. By producing tires that are lighter, more durable and less resistant to rolling. In addition, Michelin is now offering a Pilot Sport EV exclusive to electric vehicles, which needs to take these parameters more into account in order to adapt to the idea of ​​a clean vehicle. Reducing emissions associated with transporting tires to distribution points is a hot topic. Also produce locally with closer subcontractors. Michelin aims to have 40% sustainable material in a tire by 2030 and 100% by 2050.

In short

As part of the launch of the Pilot Sport 5 (car), Road 6 (motorcycle) and Power Cup (bike), Michelin detailed the secrets of developing a tire today. Of course, he did not tell us everything, the industry is extremely competitive, but enough to understand how a technological wonder a tire is, it lives its revolutions according to the demands of the market. How is a tire designed, the preferred technical choices, and the new challenges that must be met to develop this essential component of any rolling object? Here are some answers on Bibendum’s 2022 innovations.

Florian Duchiron