“The concept is as easy as nailing a piece of rubber to a barn door”, says Heinz Mariacher, Scarpa’s storied shoe designing prophet, or – more formally – climbing line manager. But don’t let his casual theorising about what he calls ‘Active Randing’ fool you. There’s more going on than Mariacher would lead you to believe. After all, the guy’s had a one-track focus on climbing shoes for well over three decades. So what is Active Randing? And what difference does it make in Scarpa’s rock shoes? Said (somewhat) simply, Mariacher’s concept of Active Randing employs rubber rands that wrap around the shoe in different configurations (for different types of climbing), designed to support climbers’ feet in the movements critical to climbing at top levels. These active rands are tensioned in ways that engage and disengage to support the foot, storing and re-releasing energy. They dynamically adapt to the foot while it loads and unloads body weight, effectively storing and releasing power—similar to the way a barn door slams shut with a rubber tether. Top right: Andy Earl applys the X-Tension system to the rock. Photo: Mark Savage Photography
Visually, you can see it in Scarpa’s rock shoes. If you look at, say, a Vapor V or an Instinct, the shoes have construction that makes them look like there is a foot in them when there isn’t. Active rands give the shoe that structure. They also do a lot more that you can’t see, but you can feel... Mariacher and Scarpa have developed several active midsole designs to work in unison with the right rubber and right upper shoe framework for ultimate fit and performance in different types of climbing. Scarpa's three central designs are: X-tension, which grabs forefoot and sides of the heel for climbers who like the maximum power and sensitivity concentrated under the big toe. Used in: Mago, Booster, Stix and Rockette.
Bi-tension, which pulls power from the toes instead of cramming them forward to achieve the same tension. Used in: Vapor series, Instinct series
V-tension, this retains the active randing principles of high-end power transfer, but uses more forgiving tension. In practice, think long routes. Used in: Force Series, Feroce.
Active randing strives to achieve maximum sensitivity for your feet and yet still allow you good edging power, which in many ways are goals that are at odds with each other. Active Randing, and the tension it creates under specific situations, allows Mariacher to build shoes which are both sensitive and powerful. If the shoe flexes in the middle or behind the toebox, “there is no strength anymore,” says Mariacher. “The shoe must help you in some way.” What distinguishes Mariacher and Scarpa from what others are doing is putting the active rand below the toes instead of in front of them to provide the same high sensitivity, maximum power transfer and dynamic return with considerably less tension on the front of the toes. Paired with specifically chosen rubber, upper materials and design, this is the third crucial element in Scarpa’s systematic framework for producing high performance shoes to accommodate a myriad of climbing aspirations. The award-winning Mago is such an example. Matching X-tension active randing, Lorica/suede upper lace-up design and XS Grip 2 rubber, Scarpa built a technical, high end shoe that balances each material’s and design’s strongest virtues in one place for state of the art fit and performance. Across the spectrum, the Force architecture is built differently: The V-tension design combines with a flat last and a dual power-strap closure to create a comfortable shoe for all-day or trad climbing, but one that can climb at surprisingly high levels. In the middle ground, shoes like the Instinct and Vapor series employ Bi-tension randing to create high-performance but surprisingly comfortable shoes that do a wide variety of things well – sport climbing to bouldering to high-end trad and even cracks. At the time of writing, 14 SCARPA climbing shoes feature active randing as a part of their architecture. *Please note: depending on your location, some of the Scarpa shoes mentioned above may not be imported to your country. This is dependent on the Scarpa distributer within that country. **Technical information courtesy of Scarpa.com