Track Pitch – A Changing Specification
When you go to replace the track on a snowmobile, you would always know what the length of the track was, and most likely you would know what the current lug height was and what the lug height was of the new track under consideration. But how savvy are you to the track drive pitch? This would be the spacing between the drive lugs on the INSIDE of the track, and this specification must be matched to the drive axle of your snowmobile. Specifically, the drive pitch would be a measurement of the center distance between drive lugs on the inner surface of the track, thus making the pitch specification very critical.
If, for example, your sled is fitted with 2.52” drivers on the drive axle, the track would be a 2.52” drive pitch. Installing a track with a different drive pitch would not work, unless you replaced the drivers (cogged wheels on the drive axle).
For many years most every sled came with a 2.52” drive pitch. Back a few years Arctic Cat introduced mountain sleds with tracks having a 3.0” drive pitch, meaning the lugs were spaced further apart, providing a healthy weight reduction. This was good, but it also reduced the number of lugs on the ground for a given track length, and also increased the likelihood of spearing the track with the ends of the rails, leading to shorter rails, anti-spear kits and further development to make the 3.0” pitch tracks work as reliably as the long standard 2.52”.
Then the longer drive pitch made its way to shorter tracked sleds, and for a number of years we have seen the 2.86” drive pitch become very popular for most every shorter tracked performance sled. Again, it was touted as a reduction in rotating mass, a very good thing when it comes to power and speed. Or so we all thought.
Enter the 2017 Polaris RUSH XCR. Look closely at the specifications for this race-ready consumer sled and you will see it is fitted with a 2.52” drive pitch Camso Cobra track, 1.352” lug height. Why? According to Polaris, for “improved acceleration”.
If you were to talk to some of the race teams that compete in the Alaskan Iron Dog endurance race held up in the brutal tundra of Alaska, you will find that many of the race teams have been switching out their OEM 2.86” track and drivers for – you guessed it – a 2.52” drive pitch track and drivers. The reason? Better top speed and acceleration. Curious, for sure.
Now for the flip side. Many times when a feature is being sold to us as “improving performance” one has to look at it carefully and ask, “how much less does it cost to manufacture?” Many times changes are made to save money, but are said to be made in the name of performance. If a track of similar length has a longer pitch spacing and the manufacturer buys thousands of them, is there money to be saved by using a 2.86” drive pitch instead of a 2.52” drive pitch? Possibly, but we just don’t know if it would be.
Now to throw a monkey wrench into all of this, Camso is just shipping a new 3.5” drive pitch version of their new for 2017 Conquer 280, boasting even lighter weight. The reduced track weight requires less rider input to handle and manipulate any terrain, and it provides increased available HP thanks to less rotating mass improving vehicle flotation and snow compaction. And yes, sleds that get this 3.5” drive pitch must install 3.5” pitch drivers, coming from Avid Products in Whitefish, Montana (sold at track suppliers like Tracks USA). The combination of the new lug geometry and lightweight design of the Conquer 280 are said to reduce rider input to initiate a turn or side hill by 20%, and reduce the amount of throttle required to maneuver through difficult terrain by 25%.
Curiously, there are a large number of riders who do in fact change out the drivers on their sled so they can install a track of a different drive pitch. In most of these cases, this change is being made more due to the availability of a specific track, or possibly to choose from more tracks, than it is to benefit from the pitch change alone. In the case of some top speed freaks, it now appears going back to the 2.52” drive pitch does seem to hold some slight gains in speed and acceleration. On mountain sleds, going to wider pitch spacing is done primarily for the benefits of a lighter weight track, but we also have to question if there is something else going on here in terms of how the spacing change effects how the snow is compacted and how this affects the sled’s ability to climb and maneuver in deeper snow. Fewer lugs in the snow means less lug surface area in contact with the snow, so there has to be another benefit here other than simply reducing weight and lug surface area.