Dirt Sleds for Year-Round Riding
This spring a few guys kept their sleds in the shop and set about transforming them for summer use. RMSHA racer Trevor Erickson spearheaded the concept and contacted the guys at ZBroz Racing to help with the project. Before long Trevor had a Polaris IQ600RR ready to be ridden in the dirt. Ray from Black Diamond Extreme also got in on the project and had a Arctic Cat Sno Pro 600 converted.
We met up with Nate Zollinger from ZBroz Racing and Trevor Erickson in the desert to get an exclusive first look at the converted Polaris 600RR and Arctic Sno Pro 600.
Why Convert a Snowmobile?
You may be asking why someone would want to go to all this work converting a snowmobile when they can simply buy an ATV that is ready to go off the showroom floor for summer use. Why? Because a snowmobile has significantly more power than even the most-powerful ATV’s on the market and the track gives the machine the ability to cross many different types of terrain - including water.
While these are major advantages there are a few big problems with a standard snowmobile that needed to be overcome before the machines would be able to be ridden off the snow. The cooling system is one such problem - a snowmobile relies on snow from the track to cool heat exchangers mounted inside the tunnel. The other issue is that skis just don’t work very well in the dirt.
The concept of converting a snowmobile for dirt use isn’t exactly brand new. A few people have tried to do it before but most have struggled with getting the suspension and cooling systems to work properly. This is the first time that I know of that any major companies have used their resources to develop a snowmobile for dirt use, with plans to sell the sleds as turn-key dirt machines.
The suspension gurus at ZBroz worked on the machines and developed a set of front a-arms that bolt up to the snowmobile ,and are matched to Yamaha YFZ450 hubs and wheel on the other end. Since ZBroz already make A-Arms for both the Polaris snowmobile and YFZ quad, it was relatively easy for them to build an A-Arm to bring parts of both machines together.
There was however a fair bit of experimenting and engineering that went into getting the geometry just right so that the wheel would clear the front of the machine when the suspension was compressed and to get the handling just right. The Arctic Cat uses a slightly different A-Arm design that is more closely matched to the snowmobile.
The spindle is made from billet and has a pressed-in hub assembly. The shocks also come from ZBroz and are EXIT branded remote reservoir units with triple rate springs.
To keep the engine running without overheating, additional cooling was added with radiators. On the Polaris machine a large radiator was mounted on the back of the tunnel with an electric fan on top, and a second radiator from an old Polaris 900 snowmobile was mounted under the hood in the location where the headlights formerly sat.
The Arctic Cat has a similar set-up, just with only one radiator mounted on the rear of the tunnel. However these are prototype set-ups and the guys at Black Diamond Extreme plan on moving all additional cooling under the hood on production units.
We rode on some small sand dunes and desert trails in Idaho. On the sand the combination of roughly 120 hp and immense traction from the track was awesome. The machine had no problem getting around. The riding style is an odd combination of snowmobile and ATV; in many ways the machine performs just like a snowmobile but the lack of soft snow obviously changes things a lot. The front end is much wider than even the widest of snowmobiles so it doesn’t help to try and lay the machine on its side. On sidehills it is much easier to straddle the machine and lean up-hill.
The most impressive attribute was how well the machines handle the bumps and whoops - like on a regular snowmobile, you can just lean back and hold the throttle wide open and fly across rough sections. Bearing in mind that I have way more hours of experience on a snowmobile than ATV, I felt comfortable taking the whoops much quicker on the sled than I would on a sport quad.
As Nate Zollinger and Trevor Erickson clearly show in these photos, the sleds have no problem jumping. In the sand the Arctic Cat had a tendency to push the front end when cornering but on the harder dirt it turned really well. As with ATVs, some of the lack of traction from the front end on the sand likely comes down to the choice of tires.
The big question on my mind after riding these machines was this; Is a snowmobile a viable vehicle for summer terrain? If the reliability of the snowmobile in the dirt could get as good or close to the reliability of ATV, I would say "Yes". The machines we rode were prototype units that are still undergoing testing and likely future units will be more dialed-in. Personally I would rather ride one of these snowmobiles in the dirt than an ATV. They are more powerful, in my opinion more stable, and the suspension works like a dream. And then there is the "wow" factor of riding a machine that many people have never seen before.
According to Ray at Black Diamond Extreme, there will be a limited number of the machines available this Fall. The initial run will be based on the Arctic Cat Sno Pro 500 (basically the sled we rode, but a production machine with a slightly smaller engine) and the Yamaha Nytro.
Once the machines are on the market there is the possibility of adding other models like the Polaris IQ RR.
The author getting some seat time on the Arctic Cat. Photo by Chad Hunter