Polaris Engineers Share Dynamix Suspension System Details

Each new season of Snow Goer magazine kicks off with a Q&A with top engineers and designers, taking readers much deeper into the new technology than they will see anywhere else. The story below was published in the October 2024 issue of Snow Goer. (If you were a subscriber, you would have seen this a year ago!). As we conduct this year’s interviews on 2026 technology, here’s a look at the 2025 Tech story on the then-new Dynamix suspension system that debuted within snowmobiling on 2025 Indy VR1 models. (Click through to see the Tech 2025 Q&A stories on the Arctic Cat 858 engine and Ski-Doo RAS RX and Pilot RX designs.)

For those who closely follow technology found on other Polaris rigs, the arrival of the much-hyped Dynamix suspension system on a snowmobile may be an “it’s about time!” moment. For others, the high-tech, quick-reacting system is more of a curiosity.

Folks in the first group may have heard about the use of Dynamix on extreme-sport RZR side-by-sides or seen videos of so-equipped RZRs eating up desert whoops. It’s been used in that market since model year 2018 to much acclaim. Some people in that group (including us!) have been dreaming about how Dynamix could impact a more rider-active vehicle like a snowmobile.

But people in the second group may have many other questions: What’s this IMU thingee that they’re talking about? How does it work? How fast can it react? Can it really change the ride characteristics of the snowmobile? Could it really improve on Polaris’ already impressive handling? How is it different from Ski-Doo’s Smart-Shox system?

To get answers to questions for both groups, we interviewed Senior Staff Engineer Mike Hedlund and then-Snowmobile Product Manager (now the Marketing Manager) Nels Eide.

SNOW GOER: The Dynamix system was first unveiled for use on a 2018 Polaris RZR side-by-side. What was learned in that application that could apply to its use on snowmobiles?

MIKE HEDLUND: “It was first designed in the off-road group specifically for the RZR. Because the number of shocks is the same, we were able to kind of configure it [for snow]. The front end is somewhat the same since you have two tires [vs. two skis]. We then essentially took the left rear [RZR shock] and made it the front shock of the skid and the right rear and made it the rear shock of the skid. By doing that, a lot of the work that the off-road group had done kind of transferred over.

“It was the off-road team that actually approached the snowmobile team and said, ‘Hey, we have this technology, we think you guys really need to try it.’ At first, we thought, ‘OK, that’s really neat, but the vehicles are quite a bit different. You sit inside of a RZR and you can’t really affect the vehicle with your body weight versus a snowmobile that is way more rider-active, so how’s this really going to work?’ The mountain bike industry was starting to dabble into it, but it wasn’t really great in that application at the time.

“So, we needed to build a prototype and see how it worked. We built the first somewhat crude prototype in the 2018-2019 winter. It was very basic – it just did a few things. It had Airborne Mode and some cornering [control] that was just really crude, but instantly all of us were like, ‘Wow, this could really be something. We’ve got to figure out how to make this happen.’”

NELS EIDE: “It has also evolved from the original model year ’18 RZR Dynamix to where RZR Dynamix is now. It started as more or less soft/medium/hard [suspension settings] that you could control with a button, with a few things to help handling a bit. It has now transitioned and grown to full ride modes. It’s really designed to tackle specific terrain and make the vehicle handle way better than it otherwise would have. That’s what I really see come out in snowmobiles. It is another level of handling.”

SG: What is an IMU, what is it measuring and how does it work?

HEDLUND: “An IMU is an Inertial Measurement Unit. It essentially measures all vehicle movements including linear movement – so side to side – and rotational movement using a gyro. So, it can measure the pitch, roll and yaw of the vehicle. It can measure when you’re accelerating, decelerating, cornering, if the vehicle is pitching – it’s constantly measuring.

“Historically, before they became cheap, [IMUs] were used in spacecraft, in aircraft and smart bombs and things like that in the military. Now that the technology has advanced, everybody has one in their pocket in their cell phone.”

SG: Your IMU is also getting inputs from other areas on the snowmobile, correct?

HEDLUND: “The IMU is already measuring acceleration, so we combined that with throttle position, engine RPM and braking information collected by the sled’s ECU. The IMU is then making decisions based on all of the information it is getting, but it has another layer of understanding what you are intending the vehicle to do. So, it knows when you’re on the throttle and how hard you are on the throttle. It then combines that with how fast you’re accelerating to know what to do with the specific shocks under that scenario.”

EIDE: “It’s important to note that there are no shocks sensors on the sled. It’s just an IMU. So, it’s not what the sled thinks it’s doing, it’s what it’s actually doing. We’re taking the actual inertia of the entire sled – you, the vehicle and everything – and using that as the input information.”

SG: How fast can it react? We’ve seen various projections of X number of times per second, but if a snowmobile is traveling at 60 mph, it is covering 88 feet per second. Can the system really keep up?

HEDLUND: “I don’t want to give an exact number, but it is hundreds of times per second that it is making changes and sampling. We aren’t really limited by how fast things can react. It’s reacting and changing things as fast or faster than the terrain is changing at the speeds we are going.”

SG: The Dynamix system comes with three specific driving modes: Comfort, Rally and Extreme. Why three modes, and what do they do?

HEDLUND: “We started with three modes because that’s what the original off-road application had. We had lots of discussion with people like Nels on the front end of the business and asked, ‘How many modes do you think we need? Is it too confusing? How simple do you want it to be?’ And we arrived back at three.

“Comfort mode is made for your average person who is just trial riding. Maybe it’s even your ‘extreme’ rider who, at the end of the day when they’re a little bit worn out and the trails are beat up, just wants a great ride. It’ll have low steering effort and zero feedback from any trail chatter but still really good handling characteristics. That was the goal of that mode. Then we have Rally mode, which is for a spirited trail rider. It’s more aggressive, and for that we wanted it to be the best-cornering snowmobile we could possibly make and be able to handle fairly large bumps that arrive on a groomed trail throughout a day of riding. It can handle whatever’s on the trail.

“Then you get to Extreme mode. It’s for the person who wants to go jump some crossings. It’s for bigger events, where you are going to be standing up and trying to see what the machine can do. People won’t ride in that mode a very high percentage of time – our thoughts are that it would maybe be 5 percent – but it really just shows off the capabilities of the system and allows you to play on a powerline without fear of bottoming out.”

SG: Let’s walk through some real-world examples. What’s happening, for instance, when a snowmobiler is scooting down a smooth trail and trying to make the machine rail through turns?

HEDLUND: “Let’s start out with coming down a straightaway and entering a corner. As soon as you let go of the throttle, that IMU senses that the vehicle starts to decelerate and, without doing anything else, it’s going to automatically add some damping to the ski shocks so the vehicle doesn’t roll forward. So that, coming into the corner, you’re already prepared to turn and the vehicle is going to stay level and not pitch up. The back’s not going to go high, the front’s not going to sink. If you apply the brakes, it just does that more aggressively. It knows the brakes are on and it knows that it’s decelerating at a higher rate, so it stiffens the front shocks more.

“Then, as soon as you start turning, the vehicle can sense that there’s lateral acceleration, so it knows that, ‘OK, we’re slowing down, I can sense lateral movement so I need to start biasing the ski shocks.’ What will happen is the outside ski shock will get stiffer and, depending on your lateral acceleration, we may make the inside ski shock softer. The harder you corner and the more lateral Gs it feels, the stiffer it makes the outside shock and the inside shock can go all the way to ‘zero.’ So there’s a complete bias on the ski shocks to make it go around the corner.

“In addition to that, depending on which mode you are in, we can also manipulate the shocks in the rear suspension to make there be more or less ski pressure. So, if you do that exact event in Comfort mode when you come into the corner, what we do with the rear suspension creates less steering effort so it goes around the corner a lot easier. In Rally mode, we do the complete opposite thing with the rear suspension so it plants the front end so you have ultimate grip when you turn.”

EIDE: “Dynamix is the only one that can control the front track shock, and that is a lot of the magic for how that vehicle balances front-and-back.”

HEDLUND: “Yeah, as you’re coming into a corner, depending on what mode you’re in, we manipulate the damping force on the front track shock to give you more or less ski pressure coming into the corner. Our competitor doesn’t have that ability and that’s one of the huge advantages of our Dynamix suspension.

“The beauty of it is, anybody who’s an experienced rider knows you can get off of your sled and change your springs and turn all of the knobs on your vehicle’s shocks and then you can go make it way better in the corner. But then you’ve made a trade-off. Now it’s not good in all of the other places you ride that day because now the skis feel too stiff, or you get a bunch of feedback from the bumps. So, then you get off [the sled] and you can turn your knobs again. [Dynamix] is doing it automatically all of the time. You never have to touch it. It just works no matter what is happening.”

SG: Now take that same scenario, but now there’s a light chop on the trail in the straights and the corner is rather bombed out. What extra things is Dynamix doing now?

HEDLUND: “The Dynamix damping calibration is speed based. So, let’s say there are braking bumps coming into the corner. As you’re slowing down, the suspension adjusts itself based on your instantaneous speed and how quickly you are slowing down. It adjusts so that you have the perfect amount of shock damping to handle the braking bumps without bottoming while maintaining comfort.

“The fact that the entire system is also speed based is essentially what adjusts it for the size of the bump. Imagine hitting that big mogul at 20 mph on your sled without Dynamix. Most likely your suspension will be too stiff because you are going slow and it may be calibrated to work better at higher speeds. Now hit that same mogul at 50 mph, now the same suspension may be too soft and you bottom. Dynamix has been calibrated to automatically adjust for events based on speed, acceleration, deceleration and other contributing inputs and will provide the perfect amount of shock damping for that drastic change in terrain.”

SG: Let’s take it to that next extreme. A hyper-aggressive rider is raging through huge, whooped-out moguls on a powerline cut and catching air along the way. What else is Dynamix doing?

HEDLUND: “If the vehicle actually comes off of the ground, we have airborne detection, so we know the vehicle has gone airborne and we adjust how stiff the suspension is going to be, knowing that there’s going to be a landing coming at some point. And based on the fact that it’s in the air plus the duration [of time in the air], we know how stiff to make the suspension so that when you land it’s going to be nice and comfortable, and it’ll be ready for the next hit.”

SG: What is the fail-safe mode? What
happens if a wire gets cut or the IMU box quits working?

HEDLUND: “The way the system is designed, if you were to get into an accident and tear a wire off one of the shocks or whatever, it will automatically put all of the shocks at full stiff. It won’t be super comfortable, but you’ll be able to ride home and it won’t be weird. For instance, you won’t have one ski shock that’s fully soft and the other one at full stiff. It’s a proven system in off-road. The majority of the components have been run in the desert, in the mud and in really harsh environments for quite a few years and it has been amazingly durable.”

SG: Were there certain hiccups you had to overcome in the long development cycle of this for the snowmobile application?

HEDLUND: “The majority focus at the start of the program was just trying to figure out how to make it work on a snowmobile. Like I said, it’s completely different than an off-road vehicle. It’s a rider-active machine versus a vehicle that you sit in. So, it took us quite a while to actually make it even better than a vehicle without it because it was like starting from scratch. The other thing that we spent a lot of time and miles on was just making sure that all of the wiring on the vehicle that goes to the shocks is super robust. Because, it’s a harsh environment and we don’t want any failures to happen.”

SG: Ski-Doo’s Smart-Shox system has now been out for a few years: Some customers love it; others say they prefer the more traditional KYB Pro shocks on an MXZ X-RS because they have more control over things like rebound for popping over moguls in mine fields. How would you say your system is different?

HEDLUND: “I’ve obviously spent a lot of time riding our competitor’s sled and ours. And when I ride the [Ski-Doo] I can never really find a mode that I like. When I put it in comfort mode it gets comfortable but then I can’t go around a corner. And then I put it in their middle mode and the steering effort is really high and it’s kind of uncomfortable. And then you put it in their top mode, and it’s like, ‘OK, I get it, it’s stiff, but I just can’t ride it here.’ I find myself switching between their modes all day. I think on our vehicle, the way we have tuned it and the way we have set up our modes, 99 percent of the day you can have it in Comfort or Rally mode and you’re just happy. I think our’s ‘wows’ people. We can tune it to be any kind of snowmobile we want. It has so much bandwidth.”

SG: Now that it’s done and the system is in the field, what about its application in snowmobiling makes you and your team most proud?

HEDLUND: “That’s a hard question to answer. There are so many things that I am proud of. I think what I am most proud of is any customer that rides this thing is going to be blown away. That’s not always the case [with new technology], but in this case, everybody that’s going to ride it is going to be like, ‘That is so much better, why couldn’t I have had that 20 years ago, my back would be better.’ I’m just proud of how well it turned out and we had a great competitor in the marketplace that was already there and I think we leapfrogged them by a long ways. We definitely don’t have a ‘me too.’ Our’s just demolishes anything that’s ever been out there.”

Editor’s Note: Every Snow Goer issue includes in-depth sled reports and comparisons, aftermarket gear and accessories reviews, riding destination articles, do-it-yourself repair information, snowmobile technology and more. Subscribe to Snow Goer now to receive print and/or digital issues.