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Skis Take Turn for the Better

Published in the September 2008 Issue Published online: Sep 23, 2008 Blog Steve Janes
"1996 Yamaha Vmax 600 XT showing the struts on the front and ski skins on the skis.
"1994 SLP Ultra Lite Skis on a Polaris Ultra Lite.
"1997 Yamaha test track in Japan.

Wood. Steel. Aluminum. Plastic. That pretty much sums up the history of snowmobile skis. But if you've only been involved in snowmobiling for the past 15 years, the plastic (or composite) snowmobile ski is the only one you've known.

As the technology in engine and suspension components have evolved, so has the snowmobile ski-both in design and in construction. The early snowmobiles, mostly made from a hodgepodge of existing products designed for other uses, started with your standard wood ski . which was quickly beefed up to sustain the weight of a heavy engine and chassis.

Then it was determined that metal was the way to go, eliminating bulk while improving durability. And your basic metal ski guided the blossoming snowmobile industry through the `60s and `70s and `80s. Back during those growing years, technology was pretty much based on what worked best on the frozen lakes of the Midwest.

But sometime during the late `80s, when snowmobile manufacturers started discovering the high elevations for late season testing, a transformation from "flatland" technology to mountain technology occurred. This was likely caused when factory engineers headed west for product testing and got tired of being stuck all the time in deep snow.

And just as snowmobile technology developers were looking at better ways to travel in deeper snow, western riders-many coming from a farm mentality of adaptation to situation-started experimenting with a variety of modifications on their snowmobiles. One common problem for western snowmobilers was snow freezing to the bottom of the skis and literally creating a snow brake on the skis. Painting or coating the skis may work for a while, but such coatings would eventually wear off and the problem of snow sticking to the skis would continue.

One such innovator from a small Wyoming community came up with a concept of "plastic shingles" for the skis. Applied just like you would apply a shingle to your roof, this outside-the-box thinker took thin sheets of plastic and layered them on his skis, securing them in place with rivets. The results: a heavy, stupid-looking mess that did eliminate snow from freezing to the skis. For some inexplicable reason, however, the shingles never really caught on.

Another creative individual in Reno, NV, came up with what was called Big Footz . an attachable fiberglass ski boot that fit over the metal skis. Just like putting on a snow shoe, this boot clamped over the ski and provided more than twice the amount of surface area for the ski to float through deep powder. And it worked . but it too was bulky and not very practical.

 

Refining Ideas

From the plastic shingles and over-the-ski boot, two different directions were taken by aftermarket companies. The first was a plastic ski skin that could be riveted to the metal ski which, unlike the shingles, was one thin layer that had a molded fit to the ski and provided a slick surface that snow wouldn't freeze to. But it did slightly increase the weight of the ski. The other direction was to build an aluminum ski that eliminated weight and was somewhat slicker than metal. But it still had an issue with snow freezing to it under certain conditions.

Companies like Koronis, EZ Glider, Erlandson Automotive and Starting Line Products emerged and started to saturate the West with skins and aluminum skis. Some companies actually combined the two-putting skins on aluminum skis. This not only alleviated the sticking issue, but it served to beef up the strength of the aluminum skis. (Aluminum skis did have a tendency to take a pretty bad beating.)

Then in 1988 a small company out of Canada stepped up with a unique concept-a composite ski riveted to an aluminum mount. The Ekholm ski represented the first generation of today's composite skis.

When the editors of SnoWest first came across this ski, we just had to have a set. We actually put them on a sled used for cross country snowmobile racing-a very punishing type of riding-and tried to destroy them over several 100-mile races. But the composite ski held tough; even when we hit stumps and rocks, the skis would flex and return to form with a memory-like concept. They were the best thing since sliced bread.

Word quickly spread through the snowmobile community about the success of these skis. However, the four major snowmobile manufacturers maintained that for "safety" reasons, the steel skis were still best.

Within the next couple of years, USI, SLP and Mountain Magic were all building and selling composite skis. In an article in September 1991 of

SnoWest, the editors wrote that the composite ski was the future of snowmobiling and all manufacturers eventually would be providing them stock on new sleds. But still, the manufacturers were slow to act . it seems that sometimes, even the best ideas just can't get past the company lawyers who are more concerned about the potential risk of lawsuits than providing the best product.

Then with the 1993 new model year, although Yamaha thought it was making a big step by offering an aluminum ski with a ski skin, Ski-Doo shook up the industry by releasing an all-new snowmobile built specifically for mountain riding-the Summit 583. And featured on this first Summit was the industry's first stock composite skis.

The very next year Arctic Cat jumped into the mix with its Powder Special, touting a composite ski and the industry hasn't looked back since.

 

Mountain Skis

Although the composite ski marked the most practical type of material for snowmobiles, the skis were still basically designed the same. Again, it took innovation from mountain riders, particularly Jim Noble of SLP, to come up with a ski design for deep snow.

Noble realized that a good ski must do three things: float through snow, turn in loose snow and handle consistently in various types of riding conditions. A good ski would slide easily, yet stay on top of the snow. Up to this point, turning and handling was all the function of a good ski runner or carbide; the more aggressive (longer, deeper) the runner, the more precise the turning. The trouble came, however, when aggressive runners became difficult to turn. They would cut so deep a groove that it really took some effort to turn the bars.

Noble designed a "rocker" keel . which pretty much described its function. Instead of a ski that would lay flat on the surface, the SLP ski would have a bow in it. So if you were sitting on a hard surface only about 2-3 inches of the ski would actually touch the surface. This rocker style proved to steer with ease while maintaining a solid steering edge.

Noble went on to add a deep keel which provided even more of a vertical steering surface in deep snow.

Today, many of the stock skis have evolved from this concept.

Other designs came out of this newly-discovered area for aftermarket products.

The Simmons ski, shaped with the side edges extruding down and runners placed on each edge, provided a very positive handling ski that eliminated "darting" (that's when the runner gets in a grove on the trail very similar to a tire in a rut).

In recent years, Simmons has added several different ski designs, including one that represents the widest ski in the industry and offers unparalleled flotation in deep powder.

With the vast improvements in ski design, the manufacturers continue to improve on stock skis. Some will claim a modern stock ski is every bit as good as some of the pricey aftermarket skis. But it is evident that ski designs offer distinct advantages for certain snow and terrain conditions. Some designs are best for sidehilling. Some are best for aggressive riding on rough trails. Some are lighter. Some are stronger. Some are very attractive. And some are not so attractive.

It really comes down to rider preference.

 

Sled Setup

But before you go and try to solve your handling issues with your ski, keep in mind that every snowmobile brand offers different handling challenges and requirements. And sometimes it comes down to how the snowmobile is set up as to how the ski will perform.

For example, if you combine an aggressive ski to a lot of front-end weight you may have too much front pressure and your sled may be hard to turn. So the rule of thumb here is the more ski pressure, the less aggressive the ski. The more weight transfer, the more aggressive the ski. (And remember, your runners also can play a role in all this).

What also comes into play is the amount of traction or push the track provides. An aggressive and/or long track will push straight ahead, requiring a more aggressive ski to turn the front of the sled. Couple this with a light front end (limiter strap all the way out) and you can find it nearly impossible to turn the sled. But if you suck up the limiter strap, you will get a very heavy front end which can cause the sled to submarine in deep powder. And unless you're running the Simmons wide skis, nothing will offer flotation.

And it's not just the limiter strap that affects how the skis perform. A multitude of adjustments to your suspension-both front and rear-can determine how much control a ski will have on the snowmobile.

Snowmobile manufacturers try to design a ski that works in a variety of snow conditions. They have made wide skis, narrow skis, parabolic skis, skis with deep keels, multiple runners, etc. Sometimes it appeared they had copied from aftermarket companies. Sometimes they have purchased the rights to use aftermarket designs. But in all, they have tried to provide a ski that could float through the deep snow and still guide a sled through a twisty trail.

Skis have been made in a variety of colors . although black seems to be the standard.

And although it's really hard to see an awful lot of engineering in your basic ski, there's still a lot of time spent testing and trying-looking for strengths and weaknesses in both design and material.

We've come a long way from the days of wood and metal. Who knows what the future may have in store?

2007 Polaris RMK ski.