Backcountry ski bindings are, in many ways, completely unlike your traditional downhill bindings. It’s good to consider them in a different light, although the goal of affixing your boots to your skis remains the same.
Backcountry bindings are different from resort or downhill bindings in that they employ a releasable heel but, in most cases, not a releasable toe. At least, that’s how they started out, and many of the more touring-focused bindings are still this way. When clicking out of most backcountry ski bindings, you will release from the toe instead of the heel, but that’s not universally true.
Alpine touring (AT) bindings allow you to change your settings so you can stomp down and lock into the heel and ski down. The bindings work by holding the boot in two distinct ways: from the toe only, with the heel piece out of the way for uphill touring, or locked in, with both the toe and the heel secure for downhill skiing.
The simple answer is that bindings work by holding your boot to your skis. They are the critical connection between your two most important assets: your boots and your skis. It’s crucial that your bindings are mounted by a professional to your specific boots.
So, we do recommend starting with your boots. You will have your boots for several seasons at least, whereas you could end up getting new skis every year. The bindings are an expensive and important investment in this system. They can easily be pulled off and remounted onto other skis at any shop.
With that, AT or backcountry ski bindings have essentially evolved into two modern camps. Camp one is born from the traditional Dynafit system, where the bindings release from the toe and are held to the boots with two contracting, nonadjustable pins. These snap together into holes on both sides of the toe, or welt, that sticks out about a half-inch from the toe of the ski boot.
The rear features another female insert that two pins fit into to hold the heel down during ski mode (downhill). The rear pins rotate out of the way when touring uphill, and this is also where you adjust for sole length and DIN.
Meanwhile, the second camp uses the rear heel welt like a traditional alpine binding to lock the heel down in ski mode. This newer type of backcountry touring binding also employs a way to use the front welt to lock the toe down in addition to the pins.