555 Jensen Dr, Medford, WI 54451 1(800) 360-5483

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Lightweight Snowshoe Design 101

In designing Northern Lites we started with the criteria of a perfect snowshoe and made compromises to fit the real world. The perfect snowshoe would allow the user to float on top of even the fluffiest snow, would weigh nothing, would last a lifetime, would go on as easy as a slipper and be just as comfortable, would not require any adjustment from a normal walking stride, would have the traction of a mountain goat, and cost no more than a cup of coffee.

The fundamental criteria for a snowshoe are floatation on the snow (surface area), and light weight, for without these features the snowshoe would not be a useful tool, in fact would be a liability consuming more of the users energy than it saves. Durability is also fundamental as a broken snowshoe is an even greater liability. Binding effectiveness, ergonomics, traction, and cost are all very important but secondary. Optimizing all these criteria is difficult as they are all interrelated, which is why there are so many different types of snowshoes available.

Four years before starting the company that eventually became Northern Lites many good snowshoes were available covering all these criteria, except they were heavy. R. Buckminster Fuller (inventor of the geodesic dome) advised students to look for “gaps” in any field and develop a profitable way to fill them and you will never be lacking for a job or meaningful serviceable work to do. In the field of snowshoes, that “gap” turns out to be the weight. Because the snowshoe frame is the heaviest component of all snowshoes, wood, metal, or plastic, unless we developed a lightweight snowshoe frame, there was no reason to proceed.

First task was to determine why existing frames need to be so darn heavy. It turns out that snowshoes are bridged between hard objects such as logs or rocks quite often. For this reason frame failure almost always occurs in the center of the snowshoe, halfway between the hard object. This is why quality wood frame snowshoes use thicker wood in the center and progressively thinner wood at the tip and tail to save weight. Because this tapering cannot be done economically with tubular metal, existing metal frames have to be beefy and heavy from tip to tail.

Bucky Fuller knew that the best way to deal with extreme loads like this is to build in “tensegrity” or tensional integrity which is a property of objects with components of tension and compression in a combination that yields strength and resilience far beyond the sum of their components. Animals and other biological structures are made strong by their tensioned and compressed parts. Muscles and bones act in unison to strengthen the other. A common example of tensegrity is a child’s balloon. When examined as a system, the rubber skin of the balloon can be seen as continuously pulling (against the air inside) while the air is discontinuously pushing against the balloon keeping it inflated. All external forces striking the surface are immediately and continuously distributed over the entire system, meaning that the balloon is very strong despite its thin material.

In a snowshoe system, the deck and deck attachments are in tension and the frame is in compression. If a system could be developed that allowed the frame to flex (like the skin of a balloon), and the deck to move (like the air in the balloon), the force of the users foot could be distributed evenly from the tip to the tail of the snowshoe, thus making it stronger and allowing it to be lighter.

After several years of experimentation the perfect combination of frame material and shape, deck attachments and location, and deck material was found. The answer ended up being multiple slippery deck attachments, a free floating tail plug, and a gentle convex shape to the frame itself, allowing all major components to move independently in a predictable fashion, adsorbing only the forces they can take.

So when you stomp in the center of a bridged Northern Lites snowshoe, the deck and clips slide slightly toward the pressure point while the frame gets slightly narrower and longer. With the deck and frame moving in opposite directions the tapered areas of the snowshoe adsorbs much of the force even though they are far from the pressure point. This is why our snowshoes have a gentle taper first than a sharper taper at the tail, to spread out the force evenly. When the pressure is relieved, the snowshoe returns to its original shape.

This convex shape fortunately ends up being very efficient in maximizing surface area, while minimizing the frame length (frame length = weight). Even the Romans knew thousands of years ago that arches were the key to great strength with less material.

Borrowing from nature our perimeter clips /cleats were introduced in 1997 and combine small fins or paddles on the bottom of each clip that attach our deck to the frame. These were based on the grouse, which grow little fingers on their toes each winter giving them added floatation and traction. Our fins are canted inward slightly to eliminate any shoe to shoe interference (no tripping on the other shoe) and durability has been phenomenal. Even though these fins are fairly small, the sheer quantity of them on each snowshoe, and their location at the perimeter, improves traction noticeably.

Our choice of deck and binding material was simple. We found that polyurethane coated nylon (used in high end inflatable boats and rafts) is 3 times more durable than the PVC and Hypolon used by the other manufacturers and has much better cold flex properties, even at -50 degrees F. We decided to put the best on our snowshoes back in 1992 and, to this day, polyurethane coated nylon is still the best. After two decades of experience, we have had no wear or durability problems with this high quality material.

We knew from the start that as the lightest kid on the block, Northern Lites needed to be the toughest as well. Thorough engineering combined with the best materials available has proven that this lightweight champ is no wimp. Our warranty is one of the best in the industry, and the reviews speak for themselves.

So while some snowshoe companies may confuse you with dozens of models for men or women, this use or that, be sure to look at the surface area and weight. These fundamental criteria are universal to all uses and users.