More and more mountain sled shops are putting holes into the tracks of their mountain sleds, following the lead of Polaris West in West Yellowstone, Montana. It is widely accepted this is where the practice became popular and took off from.
Some shops are using a hole saw and are strategically placing a number of holes (often an inch and one-eighth to an inch and three-eighths in diameter) across the center track belt between each set of lugs. It is very important to do so in a well-considered placement to maintain exact rotating balance of the track, just as with installing studs.
The gain in performance seems to be greater than any loss in â€œliftâ€ from the holes; think of a â€œsnowshoeâ€ and all of the open area and you should get the idea. It is said to reduce the rotating mass by up to four pounds (significant) and reduce the rolling resistance of the track as well. There are also some benefits to snow entering the suspension (lubrication and cooling) as well as this snow being thrown into the heat exchangers for additional engine cooling.
Some shops now offer this service to their customers as a performance enhancement. Arctic Cat mountain sled customizer Dakota Performance has been placing three holes per bar in many of their customerâ€™s M-7 162â€ sleds, seeing a 4 pound reduction that, dynamically, acts like a much greater weight loss (each pound of rotating mass is considered to be more like a seven pound reduction in sprung mass).
You can also send your track to Leland Performance (www.trackpunch.com) and they can perform the â€œportingâ€ for you with perfect alignment, using a sophisticated razor-cutter instead of a hole saw.
Even Ski-Doo has joined the fad with many of their 2006 Summit models having the holes in the track as part of the design and manufacture. They claim a two-pound weight savings with their two holes in the center belt of their tracks.