With a car or truck we always talk about the “contact patch” that is provided by your tires. On a snowmobile, we instead have a track and skis as our points of contact. This being the case, having the proper track installed for your snow conditions, along with where and how you ride, is about the smartest and most economical method of improving the performance of your sled. The track transfers all of the engine power to the snow, and the choice of track is vital in how your sled performs for you.
Most sleds come with an appropriate track (in lug height and lug profile) for the sled’s length. Short tracked sleds designed for operation on hard packed trails will have a lower lug track, better for top speed and better suited for reduced snow conditions. Long tracked sleds designed for operation in deeper snow will have taller lugs, acting as better scoops but lacking the stability for packed trails. Think of them as highway tires and deep-lug off road tires and we will have a better understanding of how they perform.
So far so good? From these two extremes we have all of the tracks in-between, and this is where it gets confusing for many riders. From our experience, too many riders choose a track that is too tall for the conditions they most often ride in. They are so scared of getting stuck that they err on the side of deep snow capability. Taller lug tracks do work well in deeper snows, but they also require lower gearing, which means the sled will run at a higher engine rpm for any given ground speed. Riding your sled down a trail or forest road the machine will be acting like you should shift into a higher gear, regardless of how fast you are going.
The deeper lug tracks also get hotter far easier, and should not be run for extended periods of time at high speeds on packed trails. They will get hot, and when that happens they can weaken, throw lugs, melt hyfax, all kinds of ugly things. Riders need to be keen to these possibilities when riding a sled designed for deep snow conditions in snow depths less than “deep”.
As the lug height gets taller the load presented to the engine increases, so the sled will need to be geared lower to allow it to operate at the proper engine rpm. This also means your sled will have a lower top speed and it will use more fuel for a given distance.
As the lug height increases, so does the concern for adequate lubrication of the hyfax sliders and cooling for the heat exchangers when operating on packed snow. This is where the use of ice scratchers comes in handy, to provide an extra spray of ice and snow to both cool the hyfax sliders and to cool the heat exchangers, coolant and engine. Use the machine in adequate snow conditions and these concerns go away.
It all depends on the snow conditions as to what you can truly get to work. As soon as you have a few days above freezing and the snow gets hard, everything changes. At time like this even a low-lug short track sled might need ice scratchers to get enough scatter snow for cooling the hyfax and the heat exchangers, but generally it has to really get hard to get to this point, usually in the Spring.
Generally, when you get to lug heights of 1.5” to 1.6” you are right there at the limit of what will work all season long in hard packed trail conditions. When we get up into the 1.75” lug height tracks we start to see the cooling issue, start to heat up the hyfax, start to feel the sled acting loose and squirrely on packed trails. And, you start to notice the lower gearing as well when we get up to the 1.75” lug heights, and taller. Yes, they do work better when the snow gets deeper, but realize the trade-offs. Hard packed trail riders should be at 1.25” in lug height. Crossover riders should stay close to 1.5” in lug height. When we get to 1.75” we are really getting away from hard packed capability and going into off-trail capability. From there the lug heights run wild, but suffice it to say that the taller lug heights always work better in the deeper snows, generally the early snows that are lighter and not as dense. As we transition later into the riding season the snowpack becomes denser which allows a sled to perform quite well with a lower lug height. We could easily argue the need for a 3” lug height early on, then transition to a 2.25” lug height for later in the season. As we all know, when the snow sets up in the Spring we see riders on crazy short sleds going places that usually would require at least a 162” with 3” lugs to get through!
This is why the tracks like the 2.5” to 2.6” lug height have been so popular, as they really do provide a good balance between the lighter snow early and then the denser snow later.