Two 600s, Tons of Fun

2012 600 Mountain Sled Shootout

Published in the November 2011 Issue November 2011 Feature Ryan Harris Viewed 7273 time(s)
"The Polaris 600 Pro RMK and Ski-Doo Summit 600 SP have redefined the 600 mountain segment. These are no wimps on the snow. In fact, they're quite capable of handling most any mountain conditions you can find.
"The Pro RMK chassis was introduced last season in the 800 but the 600 RMK had to wait until this season to get the new skin. Part of that chassis includes a coil-over rear suspension.
"Part of the design of the new DS skis on the Summit 600 SP is that the ski is shorter behind the spindle, made that way for easier countersteering.
"The Pro RMK chassis was introduced last season in the 800 but the 600 RMK had to wait until this season to get the new skin. Part of that chassis includes a coil-over rear suspension.
"Part of the design of the new DS skis on the Summit 600 SP is that the ski is shorter behind the spindle, made that way for easier countersteering.
"The Summit 600 SP features the proven and reliable 600 H.O. E-Tec engine that offers the best top end power in the 600 class.
"We knew the 600 RMK was coming in Polaris' one-year old Pro RMK chassis and we also knew what the new chassis is capable of. That's why we were so excited to ride the 600 Pro RMK and we were not disappointed.

If you are an 800 rider and you've found yourself getting bored of the go-anywhere ability your sled has, we've got some help.

Get you and a couple of your friends to start the 2012 season off on new 600-class mountain sleds and feel what it's like again to have to ride your way into the deep backcountry. Explore the areas that looked too small as you rode past towards bigger country on your 800. It's worth a shot, especially considering the advancements that the two 600 mountain sleds in this class have made over the past few years.

We spent a few days on both the 2012 Ski-Doo Summit 600 E-Tec H.O. and the 2012 Polaris 600 Pro RMK and 600 RMK. We rode the two together in deep snow, tight canyons, trees and bottomless powder. We've also spent additional time on each sled individually in even more conditions. We've had each 600 out on the mountain with its 800 mountain counterpart. And honestly, the gap between the two is not what it used to be. With the exception of long, steep climbs or steep climbs through very deep snow, we're confident in saying that a good rider can take a 600 anywhere a good rider goes on an 800. (If you don't believe us, you should have watched Carl Kuster pilot the Summit 600 around the backcountry with the 800s.)

After all the seat time, comparing notes and opinions, here is SnoWest's take on the 2012 class of 600 mountain sleds.


Which sled has the most changes for 2012?

The Polaris 600 Pro RMK and 600 RMK. They are in the Pro Ride chassis for 2012 following a successful season of the 800 Pro RMK.

The 2012 600 Pro RMK and 600 RMK 155 get a new coil-over rear suspension (the base RMK 600 144 runs a torsion-spring skid). The coil-over rear suspension is the same as what has been running for a season under the 800 Pro RMK. The front suspension is shared between the 800 and 600s, too.

On top of having a new chassis, the 2012 600 Pro RMK gets a revised engine that's exclusive to the RMK. The new powerplant includes a new fuel rail, new engine management system (ECU, stator, spark plug caps, all electronics), 2-injector system with new injectors, new port design, linked oil pump and new exhaust system with lighter muffler (the same as the 800 RMK). This new 600 has lower emissions than last year.

One thing worth mentioning is that while there are three 600 RMK models, we're only focusing on two. The 600 Pro RMK and 600 RMK 155. The third, the 600 RMK 144, is more of a crossover sled for rental fleets than its two siblings. It has a wide seat, the Rush steering system, wide Switchback running boards and a tipped-up rail with torsion-spring skid.

The 2012 Ski-Doo Summit 600 E-Tec returns in the XP chassis with a few revisions, most notably the streamline of two 2011 models (X and Everest) into one 2012 model (SP). The 2012 Summit SP 600 H.O. gets the new XP narrow seat with storage, the multi-function gauge, 2.25-inch PowderMax II track and Pilot DS skis.


Which 600 feels most powerful?

This may be the toughest question we faced with the 600s. Both engines are deceptively powerful. Their respective powerbands are so smooth that you don't feel what you would call arm-pulling power. Yet before you know it, the sled has built amazing track speed and you're moving uphill faster than you expected on a 600.

The Summit's 600 E-Tec feels like it has longer legs on the top end, while the 600 RMK's Cleanfire engine has more pull through the mid-range.

Neither engine is a brute off the bottom end-that's an 800's forte. But on the flip side, a 600 is less likely to stick itself in its own trench for that reason.


Which 600 powerband is best for climbing?

It depends on the riding condition. The Summit 600 E-Tec is better on long open climbs. The 600 RMK seems to excel in tight stop-and-go technical riding. But we could just as easily say the exact opposite and none of our test riders would disagree. These are two closely paired engines as far as seat-of-the-pants performance goes. The real difference lies in chassis and handling.

Which sled has the best front suspension?

Specific models play into this factor. All models included, the 600 Pro RMK has the best front suspension action. Why? It gets the premium Walker Evans shock package. Ski-Doo dropped its premium X-model Summit 600 for 2012 and that puts the lone Summit 600 model in second. The Summit still gets HPG aluminum shocks; they're just not the same as what is offered on the X package.


Which sled has the best rear suspension?

We love the rising rate of the SC-5M rear suspension found on the Summit. And we love the simplicity and adjustability of the RMK coil-over rear suspension. The Summit's rear suspension is better over moguls (it was even better as an X), but the Pro RMK's rear suspension seems to work better in deep snow and sidehilling. Again, the shock package comes into play as we prefer the Walker Evans shocks on the Pro RMK to the Ryde FX equipment on the RMK 155. So much so that the Summit's SC-5M skid is better overall than the RMK 155's.


Which sled has the best track?

Our test staff is split. Some of us aren't sold on the 16-inch wide track of the Summits even after all these years. Others think the 16-inch width makes the difference in deep snow flotation.

We will say this, though. We went into last season expecting a new track from Polaris and were initially disappointed that it didn't happen. Then we started testing different tracks in varying snow and terrain conditions. What we found is that the RMK's Series 5 track works a lot better than we were giving it credit for. In fact, we preferred it over Arctic Cat's mountain track in sidehilling conditions and also over a track with a nearly identical lug pattern as the Summit's. The lug pattern, pitch and durometer of the Series 5 is a winning combination in the mountains as far as technical riding and sidehilling goes. When that changes to straight-up climbing, the Summit's track kicks butt.


Which sled has the best seat?

There's no way around it: Ski-Doo's new XP Narrow mountain seat is awesome. Why? It has storage. Any $10,000 sled should come with a place to keep your wet gloves.


Which sled has the best handlebar/controls setup?

Keeping this to just the handlebars and controls, here's what we think:


RMK 155 base model


Shocked? We think the Pro RMK's handlebars are too tall and too wide and that the grip area is too wide (from throttle block to bar end hook). And that includes one of our test riders who is 6-foot 4-inches tall.

The base RMK bars are great. The height is pretty close for keeping close to the roll center of the sled (too high and you find yourself reaching out so far that you lose some balance control of the sled) and the width and grip spacing is great, although it's a steel handlebar.

There's not a better setup than Ski-Doo's Summit bar. It's straight, set at a good height and has minimalistic controls. The compromise is that Polaris has a superior mountain strap compared to the Summit's flimsy strap.


Which sled has the best skis?

The Polaris. Its Gripper ski (which is a Sidehiller with boot tread on the top) is the top OEM mountain ski.

Ski-Doo's Pilot DS ski is a lot better than previous versions of the Summit ski, but it pushes and washes out on downhill sidehills.


What do each of the 600s weigh?

These are the published dry weights from each manufacturer:

456 lbs. - Ski-Doo Summit SP 600 E-Tec H.O. 154

440 lbs. - Polaris 600 RMK 155 (base)

431 lbs. - Polaris 600 Pro RMK 155 (note: the 2011 IQ RMK 600 was 50 lbs. heavier.)


Which sled handles the best in deep snow?

That depends on your definition of handling.

If you want stability, the Summit is the better deep snow sled. If you want agility and a sled that lays over and stays over, the RMK is the ticket. Our test staff is split. And we've seen riders on each who can make the rest of us look silly. In technical backcountry riding, we'd say the RMK has the edge. Its new chassis just works in deep snow and off-camber terrain. The Summit is close, but we find ourselves turning out of the occasional line that the Pro RMK would hold.


Which sled handles the best on rough single-track trails?

This is an interesting area to address. The Pro RMK has the widest range of adjustability in its rear suspension. A soft powder setting will bottom on rough trails. If you stop and crank up the preload quickly, that's not a problem. But if you don't, then the Summit's SC-5M is a better all-around rate and will give the better rough ride quality. However, the Pro RMK has better shock equipment up front ... so where you draw the line is tough to say (the base RMK 155 has the lowest shock ride quality and bottoms most on rough single tracks). Half of our test staff would take the Pro RMK on a rough blitz; the other half would take the Summit.


Which sled is our top pick for 600 Mountain Sled?

Even the Summit fans on our test staff couldn't disagree: the Polaris 600 Pro RMK is going to set new standards for a 600 mountain sled this season. 

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