Alpine touring binding

An Alpine touring binding (also known as an AT binding or Randonnée binding) is a specialised ski binding with a releaseable locked down heel that can be used for ski touring and backcountry skiing.

During ascent, the skis are fitted with self adhesive plush skins to prevent them slipping backwards. The ski binding heels are released to allow a Nordic style of striding. The skins are very effective in preventing the skis slipping backwards (much more so than waxing) and quite a steep hill can be ascended directly without resorting to side stepping or herringboning. The heels of the bindings are often fitted with adjustable steps to maintain the soles of the boots horizontal on a steep climb.

Prior to descent, the skins are removed, the heel steps removed or lowered, and the binding heel piece is locked down. Descent is then by conventional downhill skiing technique.

Compared to Nordic boots and bindings, the alpine touring binding is less suitable for undulating terrain, but is more versatile on steeper and more difficult snow.

Like telemark gear, this equipment is popular with people from an alpine skiing background; but unlike telemarking, it requires no learning of a challenging new type of downhill turn. Because the fixed heel provides additional support & lessens the force on the toe hinge in downhill mode. Modern AT gear and telemark gear are comparable in weight with both sacrificing weight for control on the descent.

Most AT bindings have DIN safety release as in an alpine binding. Special ski boots are also used, something of a cross between a downhill ski boot and a hiking boot, which are light and flexible enough to be comfortable to walk up in while still being stiff enough to provide good control when skiing down. These boots have soles with traction & the ability to hold a crampon when climbing steep slopes with the skis on one's back.

The main manufacturers of AT bindings are Silvretta and Fritschi Diamir although Backcountry Access produce a 'standard' binding adapter to allow downhill alpine skis and bindings to undertake limited touring.

Early Silvretta's (400's and 404's) have a plate under the ball of the foot that twists out under lateral loads. Normal procedure with these is to have a leash to the leg as the bindings have no brakes.