According to Metzeler, the German tire company can manipulate the performance of its motorcycle tires by adjusting the tension of the tire’s steel cords. Metzeler calls the process Interact technology, first seen two years ago in the Z6 Interact sport-touring tire, and has imparted the new-for-2011 Roadtec Z8 tire with this technique.
Between the carcass and external compound of a Z8 tire resides more than 120 steel cords. Like a string instrument, each cord can be tuned to produce a different effect. In the case of the Z8, the result is better grip and tire longevity rather than tonality.
The Roadtec Z8 boasts three tension zones: the center and two sides. To deliver the highest mileage possible, the tension of the cords in the center zone is high. For maximizing grip, the tension of the cords in the two side zones is reduced. It’s said to offer the benefits of a dual-compound tire while using just a single compound.
The handling and grip performance of the new Roadtec Z8s was impressive no matter what model bike I was riding.
“The compound interacts with the tension of the wire,” explains Metzeler’s senior test rider, Alessandro Abate. “The higher the tension the less the tire’s compound will move. The lower the tension the more flexible that part of the tire will be.”
To simulate real-world conditions, Abate, a former Italian national roadracer, travels to Metzeler’s purpose-built tracks located in various regions around the globe. In the course of developing the Roadtec Z8, it’s Abate’s job to ride pre-production tires with a variety of cord tensions and decipher which is the best combination of tensions.
“Depending on the tension of the cord a tire can feel over-inflated or under-inflated,” says Abate. He also provides feedback on a tire’s carcass strength, durability and, of course, grip.
Compared to the Z6 Interact, the Z8’s new design is said to offer much better handling, with improvements also to levels of traction in both wet and dry conditions.
The performance and grip of the new Roadtec Z8s is quite impressive, especially for sport-touring rubber. Our day on the Z8s didn’t reveal much about the tire’s durability, but Metzeler says to expect slightly better mileage than the good-wearing Z6.
For sporty riders looking for tires with tenacious grip and extended endurance, Metzeler appears to have delivered an excellent combo in the Z8.
The Roadtec Z8s are available in eight typical 17-inch-diameter sizes. Front sizes are 120/60-17 and 120/70-17, while rears range from 150mm to 190mm wide, including the recently popular 190/55-17.
For Metzeler Roadtec Z8 Interact™ Sport Touring Tires and more, check out our sponsor partspitstop.com