Reinventing the Truck Tyre

French manufacturer Michelin claims to have reinvented the truck tyre. And following development after development over the years, this is no mean feat. According to the manufacturer, Michelin’s new Durable Technologies will offer improved mileage, payload and load capacity including gains of up to 50 per cent compared to “more traditional solutions.”

This enormous improvement is said to be down to two technological families – redesigned tread patterns including patented new siping techniques and improved tyre architecture design using Infinicoil technologt.
Michelin has labelled the tread side of its development “Tread Regeneration Experience” or “TRE-X.” This is based on two patented developments in siping technology. “Raindrop” sipes, are intended to produce a self-regenerating tread design and therefore long lasting grip throughout the whole life of the tyre, while “Double Wave” sipes, offer a three-dimensional interlocking design, making tread blocks more rigid. Michelin claims this second type of siping optimises mileage whilst retaining excellent grip.
The next development is said to be an innovation in tyre construction. Michelin have called this Infinicoil technology so apart from using a single wound piece of tyre cord, therefore avoided overlaps, this means the company is able to develop new tyre dimensions.

The Michelin XDN 2 GRIP, the presented at the new technology’s launch, is the first tyre to use “Michelin Durable Technologies” regenerating tread design. According to the manufacturer, these innovations will offer major benefits for the road transport industry, whilst considerably reducing the environmental impact of tyres by lengthening tyre life.

Michelin is not only integrating these innovations into the design of its truck tyres, but is take significant steps to introduce the new products to the trucking industry. The Michelin Group says it is going to invest 400 million euros over five years in order to do this.

Longer ‘TRE-X’

Michelin’s “Raindrop” sipes are so-called because raindrop shaped cylindrical channels are drilled through the centre of each tread block. When the tread is two-thirds worn, the channels gradually open to create new sipes, which are said to deliver excellent grip in challenging weather conditions right until the tyre is retreaded. In order to ensure continued long tread life, Michelin Remix will also incorporate the new tread technologies.

In comparison to its predecessor, the XDN GRIP, Michelin says the new XDN 2 GRIP equipped with Raindrop sipes offers 25 per cent more mileage. But there are also advantages for grip. When the tread is two-thirds worn, it Michelin engineers claim the tyre still offers 15 per cent more grip on snow and ice. According to the company, the effect is even more pronounced in the wet when the emergence of the Raindrop sipes means that the tyre could deliver 30 per cent more grip.

Michelin’s patented new double wave sipes utilise a three-dimensional interlocking desing. By working both horizontally and vertically, the manufacturer claims double locking sipes offer more grip and longer life than traditional tread patterns.

On entering the contact patch, the double wave sipes reportedly maintain their “clawing” effect at the edge of the contact patch thanks to the presence of many ridges. Inside the contact patch the three-dimensional structure limits tread block movement, maintaining optimal rigidity to reduce wear and increase mileage.

Revolutionary technology?

While manufacturers may love to call new technology revolutionary, in this case Michelin is not just over-stating the truth. That’s because the company improved tyre architecture is revolutionary, literally. The new Infinicoil technology, is made out of a giant continuous steel cord wound around the rolling circumference, which if unwound, would measure up to 400 meters long.

Michelin assures that this produces optimised rolling circumference rigidity, and an unprecedented level of rolling resistance. Because the tyre architecture is more robust, new dimensions of tyres can be made wider and with smaller diameters and longer lifespan.

According to Michelin, all this new technology means there a number of significant and tangible improvements. For example, thanks in particular to Infinicoil technology, the 455/45 R 22.5 semi-trailer tyre is said to last 50 per cent longer than the traditional 385/65 R 22.5. The new architecture also supports the design of very wide crowns, whose tread area wears more evenly.

What’s more, a tyre like the 315/60 R 22.5 on a 7.5 tonne steer axle increases load capacity by 400 kilograms per axle and with its smaller diameter, allows more cargo space. Lastly, Michelin claims its X One gives around 130 kilograms more payload per axle.
In addition to providing economic benefits, Michelin also says its durable technologies are also designed to respect the environment. For example, the use of the new more resistant tyre architecture and regenerating tread technology, offers increased productivity to Michelin customers as the vehicles are less frequently immobilised. Furthermore with if tyres are lasting longer, this reduces the environmental impact of new and retreaded tyres.

The first product to incorporate the new technology, the Michelin XDN 2 GRIP, is now available in sizes 315/80 R 22.5 and 315/70 R 22.5. The 295/80 R 22.5, will be introduced in 2006.