Cross-Country Skiing Explained (Part 4): Classic Cross-Country Ski Bindings

Copyright © 2018 Jared Manninen

Ski bindings, whether they be for Nordic skis, Alpine skis, Telemark skis, or Randonee skis (Alpine Touring), are the unsung heroes of the world of skiing. Without bindings, our skis would be rendered useless for they are the direct interface between human and technology (skis). Their purpose is to enable us to exert control over the skis. Pretty important, right? Well, the reality is that for many of us they just represent an additional cost to those already expensive skis we’ve just purchased. And after the bindings have been mounted to the skis, generally the only other times we consider them is when they break or don’t work as expected.

The design and construction of skis (and their bindings) is representative of any invention that’s required a direct human interface to operate. This interface is, and probably will always be, the Achilles’ heel of invention. Simply put, no matter how fantastic an idea may be, if it’s not user-friendly it’s not going to be used. So it shouldn’t be a huge surprise that, although ski design and construction has definitely evolved over the millennia, bindings have truly been the crux of the sport (or mode of transportation and survival).

To try to describe all of the historical mechanisms and manifestations of ski bindings would be encyclopedic in length, and is a lesson best saved for another day. Suffice it to say that for thousands of years people have been attempting to develop ski bindings that don’t lacerate, chafe, or crush their toes, feet, or ankles, cause them to break their ankles or knees in a fall, inhibit blood circulation which can lead to frostbite, wreck or destroy their boots, or simply break free from the ski. Yet the bindings still need to provide adequate control with which to run the ski and feature a relatively easy release mechanism. Throw into the equation the fact that there are many unique skiing disciplines to practice, each requiring a binding that meets its specific needs, and you have a pretty complex problem to solve.

NNN BC (auto) binding

In spite of how important bindings are to skis, the laissez faire attitude I mentioned toward them is not necessarily unwarranted. They’re not nearly as sexy as the actual skis or ski boots and they don’t require much attention after they’ve been mounted. Other than keeping them free of debris and periodically checking them for wear and tear, there really isn’t much more to do with them. I suspect, however, that the real reason many of us take ski bindings for granted is due to their evolution and subsequent standardization.

You want to know something funny, though? You can buy nearly any alpine ski boot from any manufacturer and then wear it with any set of rental skis (and bindings) at any downhill resort or ski shop across the country thanks to standardization. However, this is not the case with cross-country skis.

Why is there no standard binding used in cross-country skiing? Well, why do some people prefer iPhones while others prefer Androids? Call it the blessing and the curse of a free market. While there is no right or wrong answer as to what brand of cross-country ski binding to use, there are more effective choices in types of bindings that can be made based on intended use and you need to be aware that there simply is no across the board standardization of cross-country ski bindings.

NNN BC Magnum (manual) binding

Types of Bindings Used In Classic Cross-Country Skiing

Unlike downhill-oriented skiing disciplines where you want to be “locked in” as tight as possible (foot to boot and boot to binding), mobility is paramount in classic cross-country skiing. The foot needs to be snug (not too tight) in the boot to provide control over the ski, but comfortable enough to wiggle your toes and flex your feet. The ski boot needs to move freely in relation to the binding for you to properly execute diagonal striding. This is why the metal bar at the toe of the ski boot (the one thing manufacturers do agree on) is the only attachment point between boot and ski (except for SNS Pilot boots/bindings). And, although you’re clicked into the binding with that bar, think of this union more as a hinge rather than a fixed locking mechanism.

3-Pin binding

Assuming the cross-country ski bindings have been mounted in the standard position (pin line directly over the balance point of the ski), the ball of your foot will basically be at the apex of a classic ski’s second camber. If you’re using classic track skis and boots or light touring gear, the boots will have firm soles but soft uppers. The hinge allows you a “free heel” and, when coupled with those softer boots, enables you to flex your foot like a runner. This means that during the push-off phase of diagonal striding all of your bodyweight will be focused on the flexed foot and, therefore, compress the second camber (ultimately flattening the ski). For more information about this concept, read Cross-Country Skiing Explained (Part 3): Grip Zone of Classic Cross-Country Skis. The mobility inherent with classic cross-country skis (and their bindings) ensures you won’t be mistaken for a zombie shambling across the field because having a free heel and wearing comfortable boots allows you to move naturally, particularly when not using actual technique (i.e. negotiating deep powder by basically walking).

As I’ve stated, there is no standardized binding/boot system that is compatible with all other bindings and boots. When navigating this realm, you need to be certain of what you own or are looking to purchase. Many beginner and intermediate cross-country skiers aren’t aware of this discrepancy. And they become frustrated, for example, when they bring in to the Nordic ski center at which I work their own skis (with bindings) or boots after having forgotten one or the other at home, only to discover they can’t just rent the one missing component because our binding systems aren’t compatible. I would estimate that this occurs about 50% of the time. No big deal if you have money to burn, but having to rent a whole cross-country ski package when you already own a full setup (but forgot one of its components) can be frustrating. Usually a mistake made only once.

SNS Pilot bindings (auto and manual). Notice the hooked lever looking mechanism beneath the “head” of the binding. This is where the second bar on Pilot boots connects.

I’m not going to list every possible variation of every binding on the market for there are way too many options, but the following list represent the majority of what’s available and in use today.

  • Different versions of NNN bindings

    NNN (New Nordic Norm)

    • One lightweight bar system and a relatively wide but shallow platform
    • Variations include multiple auto versions, as well as manual locking mechanisms
    • Appropriate for classic track skis and a very lightweight touring setup (i.e. not recommended for off-track/backcountry skis wider than 60mm)
    • NNN has been around for decades and is compatible with all NNN boots (i.e. an NNN boot manufactured in 2018 will work with an NNN binding that’s 20 years old)
  • NNN BC (New Nordic Norm Backcountry)
    • One larger heavyweight bar system and a relatively wide but shallow platform
    • Variations include an auto version, as well as a manual (Magnum) locking mechanism
    • Appropriate for off-track/backcountry touring skis that don’t exceed 90mm in width, although some skiers advise against mounting NNN BC bindings to skis more than 70mm (I have NNN BC Magnum bindings mounted on Fischer Excursion 88mm backcountry cross-country skis and the marriage is perfect)
    • NNN BC has been around for years and is compatible with all NNN BC boots (i.e. an NNN BC boot manufactured today will work with an NNN BC binding made years ago)
  • 3-Pin aka NN (Nordic Norm) and 75mm
    • Three pins that seat into the “duckbill” of the ski boot, as well as a bail that locks down over the duckbill
    • Appropriate for off-track/backcountry touring skis that are wider than 90mm
    • 3-Pin used to be the standard binding found on cross-country skis, but was eventually determined to be too much binding for contemporary recreational cross-country skiers using modern, thinner track skis (replaced by NNN)
    • 3-Pin bindings have been around for decades and are compatible with standard 3-Pin boots (i.e. a cross-country skiing 3-Pin boot manufactured today will work with a 3-Pin binding made years ago)
    • Please note that standard cross-country ski 3-Pin bindings are very basic and do not incorporate cables into their design to secure the heel of the ski boot (the heavier duty bindings with cables require heavier duty skis such as Telemark or Randonee skis)
  • SNS ProLink Carbon bindings

    SNS ProLink (Salomon Nordic System)

    • One lightweight bar system and a relatively wide but shallow platform
    • New as of 2018, and is compatible with NNN
    • Variations include auto versions, as well as manual locking mechanisms
    • Appropriate for classic track skis and a very lightweight touring setup (i.e. not recommended for off-track/backcountry skis wider than 60mm)
  • SNS Pilot (Salomon Nordic System)
    • Two lightweight bars system with the first bar to connect the toe of the boot to the binding and the second to click into a spring loaded return mechanism at the ball of the foot
    • The Pilot platform feels more narrow to me and is slightly taller than NNN or SNS Profil
    • SNS Pilot bindings are ideal for skate skis (thanks to the second bar) rather than classic skis, but still can be used for classic skiing and are fine for track skis and a very lightweight touring setup (i.e. not recommended for off-track/backcountry skis wider than 60mm)
    • Variations include auto versions, as well as manual locking mechanisms
  • SNS Propulse (Salomon Nordic System)
    • An SNS binding that is designed more for classic skiing and is compatible with Pilot boots because it features a gap large enough to let the second bar of the boots sit untouched
  • SNS Profil binding featuring damage from wearing a non-compatible Pilot boot

    SNS Profil (Salomon Nordic System)

    • One lightweight bar system with a relatively shallow platform
    • Some Profil bindings accommodate some Pilot boots (not the other way around), but finding matches can be like winning the lottery
    • This is older technology and on its way to becoming obsolete, but you can still find the bindings and boots on the market

You can probably guess why so many people get confused about compatibility with cross-country ski bindings. Except for the 3-pin variety, all of these bindings accept a small metal bar (found at the toe of a ski boot) which connects the boot to the binding. To build upon this confusion, there are countless variations of these bindings in circulation. And just for good measure, let’s also throw into the mix all of those “legacy” systems (i.e. old as f— skis and bindings that still get pulled out of the attic once a year). On any busy day at the Nordic center, I bear witness to dozens and dozens of different binding systems that all perform the same basic function but are not necessarily compatible.

Although the NNN BC auto and manual bindings accommodate the same sized bar on NNN BC boots, the locking mechanism for the manual version is far more beefier and the overall platform is slightly larger.

All bindings designed for use with track skis basically perform in the same manner. Clearly, each manufacturer will argue this point, but unless you’re an avid racer or World Cup skier, you’re probably not going to notice a huge difference in performance.

There are no small, medium, or large versions of track ski bindings, but they do adjust to accommodate ski boots of different sizes. That said, 3-pin bindings are larger than NNN BC (Magnum), which are larger than NNN BC (auto), which are larger than NNN and SNS bindings. I find it best to marry the size of the binding to the size of the ski. For example, I’ve mounted a 3-Pin binding on my Fischer S-Bound 112s, but an NNN BC (auto) binding on my Fischer Spider 62s. The basic idea is that you don’t want a small binding on a wide ski or a large binding on a thin ski. Too small of a binding on too wide of a ski will not provide enough leverage to make clean turns and may actually result in you snapping the binding clear off of the ski (due to torsional forces).Too big of a binding will hang over the edges of the skis and affect performance when edging or turning, as well as possibly putting too much torque on the ski.

NNN BC Magnum (manual) in the closed position.NNN BC Magnum (manual) in the open position. Please note that I would have to pull the lever open slightly more to get the teeth to open wider in order to step into the binding. I kept the binding partially open for this photo to better show the actual locking teeth.

Considerations for Manual and Auto Bindings in the Backcountry

Auto bindings are fine for the groomers but not as ideal for off-trail and backcountry travel because they aren’t as secure and can be challenging to click in while on soft, powdery snow. For example, the spring of an NNN BC auto binding is quite firm and unless you have a solid ground from which to apply downward pressure, you may end up having to fiddle around for a few minutes before positively clicking in. I realize this sounds like splitting hairs, but it can be frustrating to go through this when the wind is howling and you’re standing in whiteout conditions. And being frustrated, especially under difficult circumstances, can lead to making poor decisions.

Another worst case scenario that can occur with an auto binding in the backcountry is that while trying to disengage from it, the opposing forces (pushing on the release button with the ski pole tip while pulling your boot away from the binding) can cause the ski to go flying down the trail or off the mountain. I see this happen often at groomed trails and, as humorous as it can be in a controlled environment, it’s not so funny if you ski goes flying off of a cliff. Actually, one of our rental customers experienced this very problem during the 2017/18 winter. He stopped at a scenic view point, pulled his skis off so he could rest a bit and take in the sights, but while removing one of his skis he sent it flying down the side of the mountain. Needless to say, he had a fairly long walk back to the rental shop. Better to just reach down and unlock the binding with your hand and then immediately flip the ski on its side or upside down so it doesn’t slide away. Even if all you have is an auto binding, you can still just reach down and manually release your boot from the binding using your hand rather than relying on the ski pole tip. This is a good practice to get into whether you’re in the backcountry or on the groomers.

One last aspect about using manual bindings in the backcountry is that they are easier to clean out any snow and ice that’s found its way into the locking mechanism.

Close-up of the 3-Pin (NN) binding. Note the small arrow pointing to the right in the lower right corner of the photo. This means I should put this ski on my right foot.

Last Thoughts about Classic Cross-Country Ski Bindings

This article isn’t about how to mount bindings, but I did want to mention a couple notes about the task since I briefly introduced the topic above. It’s universally practiced to place the pin line (metal bar) at the balance point so that when you raise the ski it will remain level. However, some people will alter their bindings so that the pin line is set just behind the balance point. In this example, their weight is set back slightly allowing the ski tips to float more when skiing downhill in deeper snow. However, by placing the binding back, you also make it so that when you raise the ski with your boot, the tip will drop. At the other end of this spectrum is to mount the binding so the pin line is just forward of the balance point. This places more of your weight forward, but it causes the ski tip to rise when you raise your boot and ski. This could be helpful for traveling in deeper snow across flat zones and uphill. My recommendation is to just mount your bindings in the standard position so as to avoid inconsistent performance. One caveat to this recommendation is that with newer NNN bindings that attach to NIS plates, you can move the bindings fore and aft quite easily. I never do this, but it is a possibility.

#1 is an old version of NNN, #2 is a manual version of SNS Pilot, #3 is a version of NNN, #4 is an auto version of SNS Pilot, and #5 is another NNN.SNS Propulse Carbon bindings. It's not very clear in this photo, but notice how wide the gap is above the white "SNS" label is. This large space easily accommodates the second bar of a Pilot boot. Look at the image of the Profil binding above and you'll see how narrow the space is, which (in that example) does not accommodate the second bar.These types of skis and bindings need to be permanently retired. Do yourself a favor and invest in some new gear if this is similar to what your current setup is.

Although I’ve discussed bindings before boots in this article, know that they should be addressed at the same time if you’re a beginner cross-country skier purchasing new gear (or gear new to you). The reason for this is that manufacturers design their boots to work with certain types of bindings. And each manufacturer designs their boots based on what they perceive to be an idealized foot. So, it’s more important to find a boot that fits your foot properly and buy it and its related style of binding rather than first buying the bindings then hoping to find a boot that comfortably fits your foot (and is compatible with those bindings). For this series of articles about classic cross-country skiing, I simply decided to write about the bindings first because they function hand-in-hand with the design of the ski, and the flow of information from ski to binding to boot seemed more natural than from ski to boot to binding.

Above is a video featuring some of the cross-country ski bindings that were highlighted in this article, and how to click in and out of them. The video also contains some brief imagery and discussion of cross-country ski boots in relation to the bindings.

Please note that I write Cross-Country Skiing Explained with the beginner or intermediate cross-country skier in mind. This is the demographic for whom I most often served while working in the outdoor recreation industry at Lake Tahoe. I treat these articles as extensions of the conversations I’ve had with those customers. That said, expert skiers could take away something of value from this article. Just know that I don’t intend to specifically address racing-oriented philosophy, technique, or gear selection. There’s far more qualified people than me out there to do that!

More articles in the Cross-Country Skiing Explained Series:

For information about buying cross-country ski gear (for beginners), please read the following articles: