Zay’s specially formulated Polyurethane outer shell is engineered for extreme cold environments and features EPE technology. Our proprietary blend of polyether polymers only stiffen up ½ as much as compared to its competition.
How does Zay differ from its competition? Zay’s polyurethane shell is not a plastic but an elastomer and remains pliable at colder temperatures.
Why is it important to use an elastomer? Think of an elastomer as a chain, each link of the chain is either soft or hard. These soft and hard links are chemically joined together which make up the outer shell. The soft link remains pliable at colder temperatures in comparison to the hard link. These soft links not only are pliable, but also act like a rubber band. Because each soft link stretches, it stores up energy and then releases it, much like a bungee cord, trampoline or a spring. This phenomenon is called Elastic Potential Energy or EPE.
How does EPE help my skiing? Since the outer shell stores and releases energy during each turn, this additional energy provides for faster edge to edge movement and requires less physical energy.
Why should I care if my boot stiffens up in the cold? As it gets colder the outer shell of a TPU boot stiffens up at 32°F (0°C) and changes your Fore/Aft balance, which in turn, has an affect on technique.
Do Zay ski boots stiffen up in the cold? Yes, the outer shell begins to stiffen up at -50°F (-45°C) as compared to TPU boots, which start stiffening at 32°F (0°C)