I’ve been a one brand kind of guy my whole life when it comes to snowmobiles. My Polaris pride is strong and has been since the old days of the Indy 500. When I rode the new Polaris Pro RMK with the Axys chassis, it blew me away. It was clear to see why it was dominating every mountain sled shootout at the time. But then Ski-Doo announced that it had a new contender in the segment with the Summit X 850. They claimed it would be as good or better than the Pro RMK, which is something I found hard to believe.

However I’ll admit, I was curious as I continued to hear more and more about how well the Summit X was performing. So when an opportunity came up for me to spend the day on one, I couldn’t pass it up. I had to see with my own eyes whether the Summit deserved the comparison to the Pro RMK. At the end of the day, I came to the conclusion that there were both good and bad things about the Summit, some of them expected, others not at all.

Photo: ski-doo

The Power

The first thing I noticed with the Summit X 850 is the power. According to reports, the new Rotax 850 E-Tec engine is one of the most powerful in its class, and I could immediately tell it was a good strong motor. However, it wasn’t nearly as powerful as I was expecting, if I’m honest. Don’t get me wrong I never felt the need for more power, or that the sled wasn’t capable of doing anything that I wanted to do. It wasn’t until I jumped back on the Pro RMK that I noticed the major difference between the two.

Technically, the engine specs on each sled are about the same. The Summit X is claimed to have 165hp, and the Pro RMK has approximately 165-170hp. Where the difference lies, is how the two sleds put down the power. The Pro RMK felt stronger no matter where you were in the RPM range, and overall the power felt more consistent and useable throughout. I should mention the RMK did have an aftermarket pipe which will make a big difference over the stock exhaust. But I don’t think it would make that big of a difference. Again that’s not to downplay how fantastic the 850 E-Tec motor is, its strong, smooth and also predictable. Just not quite what it was on the Polaris.

Photo: snowmobil

The Ergonomics

The rider position on both sleds is about as good as you could ask for when out boondocking through the trees or floating in the powder. Both are designed more to be ridden while standing up. Because they are so evenly matched, it comes down to the small things that separate these two sleds in my opinion. For example, the mountain bar on the Summit was a better design than on the Polaris. It was easier to grab when you needed it and yet also stayed out of the way when you didn’t. But really the two sleds are so well designed for the type of rider that likes to be in the backcountry where it’s deep, steep, and often in the trees, you can’t go wrong.

Photo: snomobile

The Chassis

The chassis is crucial in the overall performance of the snowmobile. That’s what provides the “flickability” and overall fun factor that makes riding such an amazing experience. When Polaris dropped the AXYS chassis it genuinely changed mountain riding as a whole, and nobody denies that. Point being is that Ski-Doo had their hands full when trying to compete against it. What they came up with was the new Gen 4 platform with tMotion rear suspension. By using a ball joint at the center hinge, the tMotion will literally flex to whatever side you’re leaning to.

Interestingly, I learned about the specific details of the tMotion’s flexing ability after spending a day on one. Only because that’s exactly what it felt like, I just couldn’t find the words to describe the sensation. The Summit X 850 is by far the most flickable sled I’ve ever ridden, but I say that with a disclaimer. Within 15 seconds of being off the trail, I did two side to side turns without even thinking about throwing a leg over. As I continued on effortlessly carving epic “S” turns in almost two feet of untouched powder, I knew it was going to be a great day.

Photo: wellerrec

I met up with the rest of the group and one of them has the Pro RMK. Finally, we were going to see these two sleds side by side and see what they were made of. The Polaris has the 155″ track with 2.6″ lug and the Summit I was on had the 154″ with a 3.0″ lug. As we went off marking up every bit of untouched snow we could find, it was clear to see these to sleds were again very evenly matched. As the day went on I was blown away by how easy it was to throw the Summit up on its side when it came to side hilling or the downhill turnaround.

I wouldn’t have thought it was possible, but actually, it was almost “too flickable.” In some situations, I would even go as far as to call it squirrely and unforgiving. If you didn’t have your weight positioned just right, you were getting bucked off. To its credit though, if you did keep your weight in the right place, it was an extremely capable sled. At this point, my buddy and I swapped sleds for a few minutes because he was also curious about the hype was warranted on the new Summit 850. This gave me a chance to feel a direct comparison as well. Aside from the difference in power delivery, I noticed how stable and consistent the Polaris was. Once you got it on its side it was gonna stay there until you told it otherwise. It was still flickable, but more consistent in my opinion. Not even five minutes after switching, my buddy flagged me down saying he didn’t like it and wanted his RMK back.

Photo: ski-doo

The Conclusion

I couldn’t have asked for better conditions to test this sled out for the fist time. The snow was fresh, soft, and deep just how we like it here in the Rocky Mountains. I went into it with high expectations of the new Summit X 850. I had to know if it was genuinely worthy of being compared to the Pro RMK. Because of that Polaris pride, I almost hoped it would be terrible. But in the end, it wasn’t. I actually had a blast on the damn thing. I think it’s possible that with enough seat time, that ease of flickability might come in handy.

However with that being said, If I was sitting down to buy a new sled right now would that mean I would be at the Ski-Doo dealership instead of the Polaris? Not necessarily. If you would’ve asked me that question prior to riding the Summit, without hesitation I would say the Polaris 10 out of 10 times. But I’ve been thinking a lot about it, and I will say this. I developed enough of an opinion on the Summit X 850 that I would need to schedule a rental or demo where I could spend a half day on each, back to back, and really put each one through its paces before I could comfortably make a decision.

The Ski-Summit X 850 is definitely worthy of being compared to the Polaris. I wouldn’t go as far as to say that it would beat the Polaris in a shootout or comparison, but the Polaris wouldn’t win by a landslide like it has in the past though either. And coming from a diehard Polaris snowmobile fan for over 25 years, I think that’s really saying something.

Photo: snomobile