Tires. They're black, round and sticky, right? Well, for the most part, yes, but advancements in tire technology have come a long way in the past thirty years. As motorcycles evolve riding styles change, and so too do the needs of the rider. The categories vary from sport-touring, canyon carving and even simple commuting, and all of them have specific needs. Gone are the days when a single tire could do it all.
But don't tell Metzeler that. The German tire company owned by Pirelli since 1986, Metzeler has been hard at work developing the do-it-all tire for quite some time now and its efforts have paid off with the Roadtec Z6 Interact. The successor to the original Roadtec Z6, the latest incarnation is officially branded as a sport-touring tire, but that's a bit misleading. You see, the definition of "sport-touring" is broad by nature, but to break it down a typical rider puts on plenty of miles, abuses the entire contact patch from edge to edge and doesn't quiver at the sight of rain. Not only that, but the steed of choice for these riders varies greatly. Some prefer dedicated sport-touring rigs like the Yamaha FJR1300, while others bend the rules and cross the country on their R1. In short, they do it all and they expect their tire to as well.
Recently, other tire companies have met these needs by incorporating multiple compounds in their tires: a harder, more durable rubber in the middle for long mileage, and a softer compound on the edges for more grip during those spirited rides. The issue with multiple compound tires comes when transitioning from one compound to another. When the rider is fully upright or fully leaned over, the tire will perform as intended. But at partial lean, when riding constantly between two compounds, the rider may experience a difference in grip levels, what Metzeler refers to as the "step effect."
The Z6 Interact is different. Instead of joining the multiple compound bandwagon, Metzeler shucks the trend in favor of its new, patented Interact technology. A single compound utilizing 30 percent greater silica makeup compared to the original Z6 allows the tire to reach optimum operating temperature quickly, while newly formulated synthetic polymers expand the usable lifespan of the tire.
So how does a tire come up to temperature quickly, provide optimum grip and have a long lifespan? The secret lies in the tension of the zero-degree steel belt radial structure. Each steel belt within a tire's carcass is comprised of a series of strands that are all wound together. Traditionally, each belt is wound to the same tension, regardless of whether the belt lies on the edge or shoulder of the tire. With the Interact process, strand tension is now adjustable based on performance needs and its placement on the tire. Strands with more tension comprise the middle of the tire, allowing balance, stability and longevity. As the strands move towards the shoulder tension is reduced, allowing the tire more flex, which then brings the tire up to temperature quicker. With the Interact system, the Z6 mimics a dual-compound tire but without the "step-effect." And though the Roadtec Z6 Interact has the same tread life as the original Z6, thanks to its new synthetic polymers, tire performance remains constant for a longer period compared to its predecessor.