Trends in Traction
Winter 2000 - 2001

A popular question this season has been “How many studs do I need for my new 800 twin?” Or, “Can I install 96 studs in the center belt and not damage the track?” Riders want the added safety of studs, but they’re looking for a trail set-up, not an all-out race set-up.

The traditional formula for the number of studs you should install is to multiply the engine horsepower by 1.5. Applied to a new 135 HP 800 twin, this would require about 192 studs from a traction standpoint for “performance” or “aggressive” applications. Many riders want the added safety of studs, but don’t like the idea of needing nearly 200 of them. What can you do?

We’ve all seen some of the recommendations; too few of studs and the pressure applied to each stud increases the potential of ripping a hole in your track. Installing more studs increases the traction and acceleration, but also requires increasing amounts of carbide to keep everything in balance. Adding more studs also increases the rotating weight, not to mention the added expense and work involved. Most riders with studded sleds have found what they personally like. Some like a “looser” feeling with fewer studs. The back end still can break loose, and they don’t have to add great amounts of carbide. Others like a “solid” feel, with a really hooked up nature all of the time. Heavier riders tend to get better traction with fewer studs, but the biggest fear for many is track damage. While studs increase traction, it is widely acknowledged that it generally decreases the useable life of the track due to the added stress it places on the belting and inner cords.

If you’re concerned about track damage and fall into what is considered a “trail” or “safety” application (which is the vast majority of trail riders), the absolute minimum number of studs you should install is 1 stud per horsepower. To reduce potential track damage even further, these can all be installed into the center belt. For a new 800 twin, this would be 144 studs in the center belt. Use the pattern for 192 studs; but only install the center belt studs, don’t install any of the outer belt studs. According to Ron Pattyn at Stud Boy, when installing 144 studs in the center belt a 4-2 pattern is preferred over 3 studs every bar. The 4-2 pattern keeps the studs closer to the slide rails and idlers for better penetration. Installing 3 studs per bar, only in the center, tends to place too many studs too close to the center of the track where they’re less effective.

Applying this logic to other popular sleds, 700 single pipe class sleds can run 120 studs in the center belt, and 600 single pipe class sleds (and smaller) can run 96 studs in the center belt. This formula trades off some traction for less rotating weight and potentially increased track issues, but should be an acceptable balance between the need for traction on ice and the weight and cost of so many studs.

For maximum track durability, Stud Boy (231-853-2323) recommends installing studs only in the center belt of the track. For a new 800 twin, this would be the 144 center-studs from their 192 stud pattern.

Many riders are concerned about track damage (studded or not), especially with the newer tracks having thinner belts. Most common is damage to the outer belts. Poor snow conditions the past few years has also been a contributing factor, as has increased track lug heights. A large amount of track damage occurs when the track is spinning and then catches something. This can happen on-trail, loading a sled onto a trailer, or off-trail (spinning track lugs catch a hidden stump or rock). Anytime your track is spinning freely, the chance of track damage skyrockets! Longer lugs also require longer studs, which results in more leverage and easier track and/or stud damage.

If you are installing studs into the outer belts and durability is a concern, the current recommendation is to use a six-bar repeating pattern. The first stud in the outer belt is placed in the center. Skip the next bar. The next stud is placed 1/8” offset from the first. Skip the next bar. The next stud is placed 1/8” offset from the first, in the opposite direction from the first. This pattern will still provide three scratch lines, but will keep the studs closer to the center of the thin outer belt for maximum durability.

To prevent outer belt damage, many riders report excellent results with the new “Power Plate” backers from Stud Boy. These backer plates have radiused edges, which provides better support for the stud and less track deflection. This backer is an excellent choice for the thinner tracks, with fewer bent corners. Another benefit is this backer doesn’t cut into the track like square edged backers, another cause of damage.

Another popular question is, “Should I install studs into my stock track or go with an inch and a quarter (1.25”) track?” Studs provide traction primarily on harder surfaces. Generally, the harder the surface (hard pack snow, ice, and frozen ground), the better the traction improvement. As the snow gets softer and deeper, the benefit provided by studs decreases. How many mountain riders use studs? You can’t have it both ways and maintain track durability. What about all those snow cross sleds with 1.25” tracks and 96 studs? How many miles do these sleds log before track damage occurs? Not the 5000 miles that one would like from a track on a trail sled.

Research conducted by SESRA proves that studded tracks have a significant impact on stopping distances on ice, providing increased safety.

Why not stud a 1.25” track? You can, but the frequency of track damage increases as the studs get longer. Think of a longer stud as a longer lever, applying more force on the track. Most riders who are seeking long term durability from their studded track will keep all studs in the center belt, and as short as possible. The Arctic Cat 0.875” ZR track is a long-time favorite for studding, due to its history of more durable performance. This lug height keeps the stud length lower. Which track do we consider to be the best in terms of durability for studding? Without a question, the 0.850” Arctic Cat (ZR) track. We know of many riders who will remove their tracks from sleds of other brands and install a studded Cat 0.850” track.

The 1.25” track lug height provides improved traction in snow. The softer and deeper the snow, the greater the benefit. Even in sloppy, slushy conditions the taller track lugs move more snow. There is a set of conditions where a studded track or a 1.25” upgrade would provide very similar benefits; softer conditions than this and the 1.25” would perform better, while in firmer conditions the studded track would be a better choice. Regardless of how well a deeper lug track works in snow, you’re no better off than the next guy if you have no studs when you encounter a patch of ice.

Woody's (517-689-4911) recommended 96 - stud "Sno-Cross" center belt pattern provides excellent track durability for sleds in the 100 HP range, including most single pipe 440/500 and 600 class sleds.

On groomed trails, icy corners and intersections are one of the main reason trail riders like to install studs. The holeshot and resulting acceleration are also attractions. While most riders understand that adding studs or installing a 1.25” track will increase the rotating weight, how much of a difference does each make? We weighed a Polaris XC track with 168 studs; 58 pounds. A 1.25” Camoplast track weighs only 48 pounds. Trade-offs and decisions; select your traction package based on your riding requirements and conditions.

Whatever number of studs you should decide to install, be sure to maintain a balance between the amount of traction in the rear with the amount of carbide on the skis. Much of the exact balance you arrive at is a matter of personal preference, but an increase in traction in the rear (studs) requires an increase in traction on the skis (amount of carbide). Many sleds require additional tunnel protection, so be sure to consult with your dealer or speed shop for specifics regarding your application.