The "blocking" of the front jaw is always a topic of discussion. Some may block rather carelessly, others think more about it - nevertheless the question arises: When, why and how do you block "correctly"? Pulling up the lever on the toe piece "blocks" the entire release of the toe piece and therefore also the lateral release of the rear toe piece, not the vertical release of the rear toe piece. No matter how often you hear that the binding is locked and no longer releases at all - the boot can still "bounce" upwards out of the pins in the heel"! If you break into a hole (e.g. cavities between alpine roses or stones) and fall directly forwards with your body weight, you will still fly out of the back part. The terms "blocking" and "locking" are ultimately misleading, as the front jaw can also open when extreme force is applied. The original purpose of locking lies in the ascent: especially on hard snow surfaces, you have to edge the ski up and thus put more pressure on the binding on the uphill side of the toe piece than on the downhill side, which would cause the binding to pop open - you lose the ski and, in the worst case, crash. The downside of the "weight that cannot be lifted with every step" of pin bindings is therefore, among other things, the lack of (or actually much more difficult) release on the ascent, especially in an avalanche, as the ski remains on the foot. A frame binding does not have this problem, the release works the same in ascent mode as in descent, the ski/walk mechanism is not connected to the release mechanism. A common mistake when locking in the operation of some models: the lever is not blocked in ascent mode, but is only pulled upwards - without engaging in at least the first stage of the locking mechanism. Can be seen here:
After the first click: The binding is not yet blocked for the ascent! Only the lever is pointing upwards. The binding is only blocked in the first step after the second click. The other stages are primarily used for the different, not exactly equal distances between the two holes of different boot manufacturers (with each stage the distance between the pins becomes slightly narrower) or after wear (plastic!) of the first blocking stage.
Descent
Locking on the descent is not intended for any pin bindings. Locking prevents the important lateral release and greatly increases the risk of injury in the event of a fall. However, older people in particular are often heard to say: "I forgot to lock it!" - such statements are sometimes based on half-knowledge of how the whole system works. Many false releases with low-tech bindings occur due to the "incomplete engagement" of the pins on the front section. Most of the time you have some snow, ice or dirt in the front boot inserts. Or - and this is the much more common case - there is snow underneath the center bar (where the steel springs are placed) and the bar can't snap all the way down. There is a very simple trick here to ensure that the front pins sit correctly: before each descent, block the toe piece briefly and then push the lever back down into the downhill position - if the pins have not yet engaged properly (either due to resistance in the boot inserts or underneath the center bar), you can see on closer inspection how the pins move minimally into the holes in the boot or how a little more snow is pushed out underneath the bar. These one or two millimeters are just enough to ensure proper functioning. Trick #2: Below the center bar, the snow can ice up and you may not be able to get into the binding at all. To avoid this, simply put the toe piece back into ascent mode immediately after getting out (lever up). When you return to the ski depot from the summit, nothing stands in the way of you getting on without any problems. There are also other types of false release, which are more or less frequent depending on the ski. The cause is the toe piece of classic pin bindings. The "release value" is not adjustable. According to a non-scientific study on Wildsnow.com, the force required to open the front jaw varies between 60 and 150 Newtons when pulling directly on one arm. So there are striking differences between the various models and manufacturers. For some riders (the majority!) the "Z-value" of the front brake is simply not sufficient, depending on the model. In addition, the same rider would tend to need a higher Z-value with pin bindings than with alpine bindings due to the lower friction between binding/boot. However, the main problem is probably the lack of elasticity of the front jaw. Where an alpine binding can withstand smaller bumps (= movement of the boot) without any problems, the pin binding already opens up.
A matter of taste
Personally, I sporadically block the binding when there is enough snow on the descent. I know that this puts me at a higher risk of injury and that the skis could possibly pull me down in an avalanche. The main reason is the possibility of searching for skis. Stoppers are simply too unreliable for me in the backcountry - I've already searched for the ski umpteen times because stoppers are of little or no use on steep slopes in hard snow or loose powder and the ski still runs away. In three out of four binding releases, the ski broke off in the backcountry despite the stoppers, and I've said goodbye to them ever since. Of course, we no longer talk about catch straps. I never block in early winter, the probability of hitting the famous sharks is too high or breaking into holes simply happens too often. For steep descents, the blocking function is a blessing: a ski loss should absolutely not happen on real steeps. On jumpturns - especially in hard snow - a large lateral force may be exerted on the binding on impact with the snow surface, but release is absolutely undesirable. So: close at the front, lateral release blocked, safety plus for steeps. Dynafit has the "Expedition" binding in its range, where the rear jaw is fixed and cannot rotate. The binding has only one release path: vertically to the front.
Conclusion
Basically, a pin binding should only be blocked on the ascent so as not to lose the skis. And properly locked. Locking on the descent should be carefully considered, as it practically prevents lateral release completely and vertical release only on the toe piece. For steep descents where losing your skis is definitely a bigger problem (resulting in a fall) than a possible avalanche risk or physical damage due to non-release, the locking function of tech bindings on the descent may be an advantage. Some newer pin bindings have modified toe pieces that have been optimized to prevent false releases. These, as well as special racing bindings, are covered in separate articles.
