When Ski-Doo introduced their new Gen 4 REV platform, riders of all brands immediately knew there was a new standard being set with the next-generation REV platform, powered by an all-new 850 E-TEC direct-injection 2-stroke power plant.
Since that 2017 introduction the MX Z 850 has evolved from the first X-package sleds to the more capable X-RS package, and now to the pinnacle of the platform – the 2021 Ski-Doo MX Z X-RS. Designed for the most hard-core enthusiasts who want the features, technology and look of the MXZx 600RS snocross racing sled it comes back for 2021 with an even more capable suspension package, front and rear. Compared to the popular MX Z X-package, the key differences are found in the shock calibration (more aggressive) and the steering system (rack style vs. single pitman).
With its precise handling and industry-leading suspension performance from race-sled-spec KYB Pro shocks, the MX Z X-RS has earned a passionate following in snowmobiling. It becomes even more capable and precise for 2021 with the next generation front and rear suspensions in the REV Gen 4 platform. The design and calibration of the rMotion X has truly caught up to the Gen 4 platform and the results are just as impressive as you would expect. You’re better suited to hammer down through the moguls and work in harmony with the RAS X front end, giving us world-class capability and control with big bump compliance and ride quality.
The platform’s narrow, compact design continues to allow the rider to move around the sled – extreme leans to the inside or standing up are totally natural. You can place your body mass where you want to and in the location that better controls the machine, instead of the machine controlling you. Ski-Doo has given us this capability for five years where the competition is finally catching on to this capability.
Up front is the most precise Ski-Doo front end yet, the RAS X design with racing-derived rack steering system. Where the MX Z X sleds used to feature the more precise rack steering, Ski-Doo took this feature away from the MX Z X for 2020 and now only offers it on the high-end X-RS packages.
New for 2021 are KYB Pro 36 shocks with higher performance and wider adjustability. Most riders will be able to make the front end softer or firmer (instead of just firmer) as the window of adjustability is quite wide. For both compression and rebound damping the target of shock damping is mid-range in the adjustment window, so riders can go either way according to their liking or conditions.
And then there’s the engine: the Rotax 850 E-TEC with its instant response. It lifts the skis at will. The 850 hits hard with strong power up top and way more through the midrange. Use this power carefully, as the smaller 9.5 gallon fuel tank will be emptied quickly when you are cranking on the throttle all day long. It takes more fuel to make more power, that’s a fact. The 850 closes the gap between 2-stroke and 4-stroke torque and has proven to be extremely reliable – for a two-stroke.
This sophisticated and tough new MX Z X-RS is wrapped in new Titanium Silver metallic coloration with intense BRP red accents. Not everyone is sold on this color combination, so a Triple Black option is also offered from the factory as is the Quick Adjust System featuring running-board-mounted preload and compression adjusters with or without the new Pilot TX adjustable skis. A RipSaw track with 1.25 in. lugs is standard, but a 1.5 in. Ice Ripper and 1.6 Ice Cobra (with titanium studded lugs) are also available.
What makes the MX Z X-RS different from the MX Z X package?
KYB PRO 36 Front Shocks
These shocks are standard on the MXZx 600RS race sled – so you know they’re extremely capable and durable for control in the toughest conditions. Remote reservoir design for performance and they are a rebuildable/revalvable. Easy Adjust compression damping knob makes calibration tweaks quick and easy; rebound adjustments are standard as well.
X-RS rMotion with KYB PRO 40 Rear Shocks
This is what sets the MX Z (and Renegade X-RS) apart from all other sleds – rMotion X with KYB PRO 40 shocks. Provides more capability, more comfort and more adjustability. Separate spring and shock dynamics combine with the most rising-rate/progressive motion ratio in the industry to give the rMotion X suspension a supple ride in small bumps with added capability in large ones. And there’s no need to be a suspension expert to enjoy the capability and awesome ride – with its broad sweet spot, you can set it up once and it will perform impressively in nearly every condition.
Forward Steering Post
Designed for the toughest terrain racing, the X-RS package includes special features. The steering post is more forward for the most aggressive cornering and stand-up riding position. The X-RS also comes standard with the BRP-exclusive Forward Adjustable Riser, now better in line with the forward steering post.
RS Wide and Reinforced Running Boards
Designed for aggressive stand-up riding, they are flatter for most of their length, wider and strong. Thicker aluminum sheet (3 mm vs. 1.8 mm), plus front and rear reinforcements to withstand tough landings. Go ahead, ride it hard, ride it fast, it’ll reward you for the effort.
Rack Steering System
For added precision, the rack steering system totally eliminates bump steer and provides less feedback through the handlebars. Bump steer refers to the variation in ski alignment as the suspension moves through its travel. Instead of having the ski alignment changing as the suspension strokes, the skis and runners are held even closer to perfect alignment. MXZ X and Renegade X package sleds came with this feature from 2017-2019, but starting with 2020 they switched to the single pitman arm design as found on the MX Z TNT and Renegade Adrenaline models where there is slightly more bump steer.
2021 MX Z X-RS Ride Impressions
Our saddle time on the new 2021 MX Z X-RS was nothing short of AWESOME! We had just completed a season of over 2,000 miles on a 2020 Backcountry X and over 2,500 miles on our 2020 Renegade X, and the very first thing we noticed was the added width of the front end. As small as this might seem on paper, you notice the difference immediately. It doesn’t take more than a couple of miles and you know it. The front end is clearly more stable, more planted, more confident.
We can’t attribute all of what we noticed simply to the wider front end, as much of the handling behavior of a snowmobile is influenced by the front arm of the rear suspension and this is where the magic truly lies in the new rMotion X rear suspension. The rMotion was originally developed for the REV XS platform, a direct descendent of the 2008 REV XP architecture. When the Gen 4 platform was introduced for 2017 the rMotion was a carry-over design and it has really taken great time and effort to improve upon the design.
The price we paid for the centered mass and newly acquired agility of the Gen 4 platform when it was first introduced was that it wasn’t as planted or as stable as the previous REV XS/XP platform. We noticed this immediately. This originally was thought to be more a function of the platform than calibration, as having the mass more centered aids the agile left-right response so sought after for stand-up off-trail riding, but also diminishes the tendency to stay flat and level when used in trail applications. The previous XS platform was more settled in the corners, where the Gen 4 was more responsive. Not a bad thing, but something seasoned riders easily noticed. Maybe not right or wrong, but again, riders noticed the difference. Active riders liked it, seasoned trail riders maybe not so much.
Since the 2017 introduction of the Gen 4 platform, Ski-Doo engineers have been working on this revised rMotion X to optimize its integration into the Gen 4 platform. Adjustments have been made to compensate for the mass centralization in an effort to settle down the front end for trail riders railing around corners.
Now the 2021 brings us back to that feeling of confidence, plus having all of the agility and maneuverability. I almost hate to say it, but when you ride it you’re telling yourself, “this is what I’ve been looking for!”
Power and clutching seemed to be exactly what we have become used to from the 850 E-TEC, spot-on and consistent. Zero complaints here. But that wasn’t where the changes were made for 2021 so we didn’t expect any differences here. It really manifests itself as more of a handling improvement than anything else. Some riders get confused when we say this, as they think that with the new rMotion X that the differences should be found in the ride quality or bump absorption, but the rear suspension does so much more than just swallow the bumps, it provides the balance and controls the weight transfer which dictates the ability to keep the skis in contact with the ground for constant control. Too much ski pressure and it becomes difficult to steer. Not enough ski pressure and you go straight instead of steering around the corner. Yes, the rear suspension bump compliance is refined but what you will notice far more is how the sled behaves and handles in terms of responsiveness and your ability to corner in confidence and control.
While we have always liked the added adjustability of the rMotion rear with the optional Adjustment Package, many of our riders have not been too fond of the adjustable Pilot TS skis for anything other than hard packed trails. For the 2020 models Ski-Doo made some changes to the profile of the Pilot TS skis and they worked quite a bit better for us, to the point we actually left them on our Renegade X for the entire season. We were of the opinion that a sled like the Renegade X-RS would have been better suited with the Pilot 5.7 skis or even the more aggressive Pilot RS skis. The adjustable Pilot TS skis just didn’t seem to be a match for the X-RS and its more aggressive package.
Finally for 2021 Ski-Doo has given us the ability to choose what skis we want on the MX Z X-RS when you choose the Adjustment Package – the new Pilot X skis or the new adjustable Pilot TX skis. Our test sled was fitted with a set of pre-production Pilot X skis, meaning they had the proper profile and carbide but were machined instead of molded, and we believe they were of a slightly different material than what the true production skis will be made of. They are a step up in terms of aggressiveness compared to the Pilot 5.7, so at times they still take a fair amount of effort to crack the handlebars from straight forward, but when they bite they do so with more authority in a wider range of snow conditions. Now, we really did like the Pilot 5.7 skis as we would mount the second carbide runner to the outside edges for added bite and durability, so we’re not going to immediately jump on the bandwagon for the Pilot X and TX skis quite yet. Buyers of an X-RS should all be seeking something more aggressive than the Pilot TS and some will want more than the Pilot 5.7 so the more aggressive Pilot X skis should be a welcome improvement. Skis are a very personal item on a sled and it is VERY difficult to please everyone, as this is one of the very first things that riders will change to better match their personal preferences. We say give them a few rides to see how they work for you in some variety of trail conditions before you swap them out for your traditional faves. How else will you know if you made an improvement unless you first try it as delivered?
When we discovered we would be getting a pre-production 2021 MX X X-RS for Spring testing, we asked Polaris if they would be able to send us one of the few 2021 Matryx 129” sleds they had so we could do even more side by side testing. Unfortunately they had very few Matryx sleds built so it didn’t work out. We were able to spend four days riding them back to back and side by side in February and what we learned is that while Ski-Doo made serious and noticeable improvements to their sleds with the new suspensions and skis, Polaris made the necessary changes to their platform to allow the rider to move around like we’ve been able to do on the Gen 4 REV for so many years. The Polaris remains an easier steering machine and while they’ve improved the ride comfort with the Velocity Series Walker Evans shocks, they still do not have an rMotion in there. They are now more similar than they used to be, but still quite different.
For Ski-Doo it’s a good thing they stepped up their game simply because of the pressure now coming from Polaris. Competition is a good thing, as it forces them to work harder and make better equipment so we all win. We know that, based on our 1,300 miles on our 2021 MX Z X-RS, that people lucky enough to buy one of these sleds will not be disappointed. Rather, they will know they have the very best sled money can buy and they will enjoy every minute and mile they get to ride it.
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