2021 Polaris RMK & KHAOS

New 2.75” Track Option, New QuickDrive2 Belt Drive

In mid-January we had the chance to ride the 2021 Polaris mountain sleds in some extreme snow conditions. What we learned is the 2021 Polaris RMK is the most predictable & lightest weight mountain sled that is available.

For 2021, Polaris is raising the bar again by expanding the Khaos series with two new, longer track lengths. Also, they are offering an all new lightweight 2.75” lug height track and a revised QuickDrive2 belt drive system on many Snow Check models. These changes may seem small on the surface, but they really do enhance the RMK providing improved ride quality, predictability and playful agility for their best lineup of mountain sleds offered to date. The biggest challenge to consumers will be deciding specifically which combination to order for their riding style and snow conditions. Read further as we go into depth to help answer these questions.

2021 RMK Track Options:

Series 6 track – 2.6” lug, 2.86 pitch offered in 155” and 163” varieties all in belt drive, QuickDrive or QuickDrive2

Series 7 track – 3” lug, 3” pitch offered in 155”, 163” and 174” varieties with belt drive or chaincase (chaincase in season), utilizes a 7 tooth track drive sprocket

Series 8 track – 2.75” lug, 3.5” pitch offered in 155” and 165” varieties all in belt drive, utilizes a 6 tooth track drive sprocket

Which track is right for me?

The 2.6” lug, 2.86” pitch has been our favorite track since the release of the RMK AXYS platform. It is a fantastic all around track as it performs well in all snow conditions. We still see this track continuing to be a great choice for many RMK riders. If your riding areas/style provide a wide variety of snow conditions or if you have to ride a fair amount of trail to get to that heavenly powder, this is the better track option for you. The more the snow is set up, the more you want this track.

We can not stress this enough – too many riders purchase a sled with a track lug height that is too tall for the snow conditions they most frequently ride in. Polaris offers many track options to help riders best match their sled to the conditions. Taller is not always better! Track speed is often times the deciding factor, not lug height, in where and how far you can go. The deepest lug tracks are poor performers in firm snow conditions and increase the likelihood of lug damage, delamination or worse yet, track failure.

The all new 2.75” lug 3.5” pitch track is 5 pounds lighter than the similar length 2.6” lug, 2.86” pitch track. The weight savings comes from the spread-out lug pattern with less overall lugs and crossbars. In the snow, you can feel how much quicker this track spins up and accelerates. So far, our testing has shown that the deep powder performance of it is better than our beloved 2.6” lug track, but below its 3” lug counterpart (see our comments on the 3” lug track below as they may surprise you). There is little question that this is a great all-around track. Its lightweight, spread lug design makes it respond lightning fast to throttle inputs. It accelerates fast on the mountain trail, performs well in deep snow but does vibrate a bit more at high speed due to the 3.5” pitch which spreads out the lug and crossbar pattern. We are excited to spend more time with it over the course of an entire season’s riding conditions. Currently we feel that if you are riding in a wide variety of snow conditions with only moderate distance trail burns to get to that deep snow treat in the backcountry, and want the lightest possible RMK combination, this is the track for you.

On the surface, the real news appears to be the 2.75” by 3.5” pitch track, however, when riding these sleds, the belt drive 3” lug by 3” pitch track combination is just as significant a change. Until now, the 3” lug track has been too one-dimensional for our riding style (only performing exceptionally well in bottomless powder snow). After riding them, it was very evident that the 3” lug track works much better when combined with the belt drive than before. The difference was significant enough that we wondered if they had made some changes to the track itself. We were in deep powder and the sled would lift right onto the snow. The response was quicker making the sled more agile and playful than before. We attribute this mostly to the belt drive; however, this was on a 163” Khaos with the Walker Evans Velocity shocks and we know the Khaos platform helps with agility as well. On the mountain trails, this sled felt a bit slower in acceleration than the 2.6” lug track we are so familiar with and top speed is definitely harder to attain (Polaris recommends not running this track over 60 mph for maximum durability). We attribute this to the heavier weight and larger lug of the 3” track. We would position this track as the deep snow “go to” track. If your riding consists of mostly deep, light, fluffy snow, without a lot of trail miles to get to it, this is definitely the track for you. This track provides the most lift in deep powder snow conditions of all the tracks offered by Polaris. And now without the weight penalty of the chaincase this track combination has become a real weapon.

The Khaos chassis expansion in the RMK lineup is also a noteworthy change. It was only offered in 155” last year, with 163” and 165” options now added for 2021. We have come to love the Walker Evans Velocity Series shocks the Khaos is equipped with. Ride quality with this package is better than any suspension package Polaris has offered on the RMK to date. It is as good (or better) than any competing model. And, with the Khaos platform, the sled becomes more playful and agile from the front end lift offered by this package. We welcome this change and now with the option of longer track lengths, the Khaos will definitely be a part of our build sheet.

Want more snowmobile content like this? You can subscribe to SnowTech Magazine using the link below! Starting at $15 per year.