bindings
bindings
A randonnée or alpine touring binding's primary function is to hold your boot securely to your ski, but it must also allow the ski tourist to maintain a natural stride while skinning on the flat or uphill. To enable this, all randonnée bindings allow the skier's heel to lift when in touring mode but lock down for descending (telemark bindings also allow this upward movement of the heel, but all of the time). Most have adjustable climbing levels at the heel for varying degrees of slope steepness as well.
There are two basic classes of randonnée bindings - the hinging shaft type, essentially an alpine binding on a stick (actually, titanium or carbon fiber rails) with a pivot at or near the toe, and Dynafit, which requires a special boot. The Dynafit system incorporates pins on both sides of the boot toe that hold the toe down but allow the heel to lift, and a separate pair of pins at the heel that engage a set of slots in the boot heel when skiing. In the illustration below, the top four bindings fall into the first group, while the bottom three are Dynafit.
Some randonnée bindings require a touring-standard sole shape (higher than an alpine DIN sole at the toe, with a rocker or curvature under the ball of the foot), though many will adjust to fit an alpine boot as well. Some models of bindings (notably Silvretta) have a bale attachment for the toe that allows use of plastic mountaineering boots. To save weight, many of these bindings have no actual toe release mechanism; the bindings release both forward and laterally at the heelpiece. Using your alpine boots with a beefy randonnée binding like the Fritschi Freeride is a popular solution for those just getting into touring, but once you start spending much time away from the lifts you will probably feel an urge to rid yourself of the extra weight (the rigid nature of alpine boots is not ideal for touring, either).
Those coming from an alpine skiing background should be aware that no randonnée binding offers the same level of retention as a good alpine binding. Anti-shock and return-to-center capabilities, in particular, are somewhat limited by the pared-down designs, so expert alpine skiers should beware during the trial period and work up to power skiing and air gradually . . . typically, shocks that would be non-problems with a Salomon or Marker can easily cause a release.
Back Country Access also markets an adaptor called the Alpine Trekker which allows skiers to use their alpine setups for touring. It is basically a hinging plate that fits alpine bindings and allows skinning in alpine boots, but is carried in your pack on the way down. The Alpine Trekker, combined with alpine skis, boots and bindings, is quite a heavy solution and is probably not an option if you plan on touring more than occasionally.
For detailed information on most popular randonnée bindings, plus downloadable PDF templates for home-mounting them, I highly advise checking out Lou Dawson's excellent website, http://www.wildsnow.com - his FAQ pages regarding Dynafit bindings are especially worthwhile.
© 2007 Gregory C. Louie