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Grand Lake, Colo., is a spectacular place to chisel a highmark on a gnarly crag. However, for our spring tests with the manufacturers, warm temps melted much of the high country snow, and with the thaw came concrete-hard conditions in the morning and squishy slush in the afternoon.
Carving a highmark was too easy on the solid snow, and testing the industry's best mountain sleds in their element wasn't exactly possible. For the most part, a fan-cooled 121-incher could have climbed every mountain (and some did).
So, here we'll run down the technical upgrades, the ergonomics and our general feelings about the sleds, but during the season we'll test which one is really best in powder.
Polaris 800 RMK DragonPolaris has gotten back to its roots. Last season our mountain test crew thought the 700 Dragon RMK, had it been an 800, could have been the mountain sled of mountain sleds for '07. Well, '08 brings us an 800 Dragon in two sneaker lengths, 155 and 163 inches. So was last year just talk?
No way, the 800 RMK Dragon is raw, slender and sculpted at 487 lbs. If you want one, get to your dealer and hope the lottery is in your favor, as these are limited build sleds.
Polaris says the 800 will kick out 155 horses, although Starting Line Products, in Idaho Falls, Idaho, has pulled 158 ponies and some change during a dyno run. That power combined with the Dragon's light chassis will make mountains wiggle under this rocket.
The 800 is based on the same block as the 700; it's a twin where fuel and air are inducted on the motor's backside and the spent fuel is exhausted in front. Polaris' proven Cleanfire electronic fuel injection system, with two injectors per cylinder, gives the motor crispness. The mill is a mono-block that weighs just 2.5 lbs. more than the 700.
Track is Polaris' 15-inch wide Series 5.1 that dices the snow with 2.4-inch lugs that are slightly staggered for optimum hook-up. The track also has large open windows that keep the hyfax cool, and it lightens the track to reduce rotating mass. This Dragon also comes equipped with Holz ice-scratchers.
Bump soak comes by way of Walker Evans Air Shocks for the front suspension and on both ends of the rear skid (comfortable, yet aggressive).
The 800 has a sweet balance spot, so rocking it up on one ski, and stabbing the ski's edge into a sidehill seems effortless.
AmSnow's mountain squad is adamant that the RMK is the easiest mountain sled to roll onto a ski edge, and it feels lightest through the handlebars. This is accomplished through reduced weight, tall riser-block handlebars, handlebar swing that is controllable and superb balance. Counter steering to carve a ribbon is simple.
Credit Polaris for developing a cockpit with a tall, firm freestyle seat, wide grippy running boards, simple controls, flat handlebars with adjustable hooks and a sculptured tank that feels dirt-bike friendly. This minimalist's thinking testifies that Polaris is listening to the mountain riders who swear that less is more. Less weight is, well, less weight, plus there's less that can go wrong.
Oh, the RMK 800 Dragon also is a mean-looking beast that was born in the mountains. This will be Polaris' redemption in the mountain market.
Yamaha FX Nytro MTXYamaha keeps chipping away at the power-to-weight issue. The MTX is the only 4-stroke in this class, and that's just fine with Big Blue.
While shy on horsepower compared with the 800s, Nytro competes well in this class, partly because of the diet it has been on. Ski-Doo's REV-XP-based Summit is soaking up all the glory as the biggest weight loser, but that depends on how you look at it. The FX Nytro MTX is 90 lbs. lighter (544 lbs. w/o reverse) than the snowmobile it replaces, the Vector Mountain SE. In addition, the EFI 3-cylinder motor spits out 10 more horsepower, says Yamaha. But, our Tech Editor got a chance to dyno it and found 138 ponies. (See
Dyno Test.)
AmSnow's Senior Mountain Test Rider, Kevin Allred, says, "I like how this sled feels. It works great in the trees, is easy to maneuver on a steep climb and when sidehilling. I can tell it's light. In fact, it feels as light through the handlebars as the 2-strokes."
This is not a Phazer with one extra lung, but a purpose-designed mountain sled. Yes, it's Phazer-esque in looks, but the Nytro MTX has more to offer. For instance, its engine braking reduction system allows the motor to free-wheel like a 2-stroker when the throttle is released; that feeling of an anchor being tossed off the back is diminished.
Nytro sports a Yamaha ProMountain 153-inch rear suspension with 11.5 inches of vertical travel. The Camoplast Maverick track churns the snow with 2.25-inch lugs. This track, similar to the Apex MTX track, is 1 inch narrower, 15 inches rather than 16 like Apex and Vector SE were last year. All this meat is turned by 7-tooth extrovert drivers. Gas cell shocks control vertical movement.
Up front, the Nytro's ski stance can grow by 2 inches, from 37.6 to 39.6. Vertical travel for the front suspension is 8.5 inches. Bump soakers are HPG aluminum bodied shocks, and again, Yamaha delivers the best OEM mountain ski.
There are tall hooked handlebars that are wide and grippy, and a mountain strap is on this one. The bars are positioned well in relation to the toeholds that, along with wide running boards, allow the driver to stand upright with confidence when busting through the thickets.
Nytro has overcome much of the hype surrounding other new mountain sleds and is pushing Yamaha's 4-stroke versatility and efficiency. The Nytro is our most improved mountain sled of the year.
Arctic Cat M8We still love this sled! Cat's mountain line started the weight reduction push with the 900 1M/King Cat, followed by the M7 and continued through the 800 and 1000 M series. Now, Cat has sucked even more weight off for '08.
Cat also has built a reliable reputation on its battery-less electronic fuel injection (EFI) system that feeds its Suzuki motors with fuel and oxygen. Like its 700 predecessor, the 800 is a lay-down motor, pulling in its air charge in the motor's front and exhausting on the same side. The EFI system works with large 46 mm throttle bodies. The motor comes equipped with a knock sensor to prevent engine failure due to lean conditions or rotten low-octane fuel. Four spark plugs - two per cylinder - fire the fuel-oxygen mix.
Last year, some mountain purists were dismayed that Cat put an 11-lb. electro-mechanical push-button reverse on the M-line, but now, no one wants to go without it.
The M8 comes in 153- and 162-inch track lengths, and buyers can choose a standard or Sno Pro edition; the latter including Fox Float shocks up front and some titanium in the rear skid. The M8 spins Camoplast's 2.25-inch Challenger track, which is an all-around good track that will claw and gnaw its way up a slope. Could Cat commission a track builder to make a lighter track? Yes. Should they? Yes. But, is the Camo Challenger track lazy and ill-equipped? Heck no.
Handlebar swing for all the M-sleds is more horizontal than vertical. This allows arm leverage to be central to the driver's chest. Why is this? The steering post is under the motor. However, the bars still need a 3-inch riser block. Compared to other mountain sleds, the M8 has the lowest bars.
Cat overhauled the front suspension and added race spindles. This reduced weight and the steering arc by 10 degrees, making the M8 a sharp turner.
Cat also shaved 9.5 lbs. from the rear skid frame by building an all-new rear suspension. Most of the weight reduction came from removing torsion springs. The new rear suspension has less unsprung weight, and it minimizes track tensioning when the rear skid travels up into the tunnel. Lightweight aluminum FOX Zero Pro gas shocks dress out the suspension.
The running boards here also got revamped with large openings where the driver's boots rest, to help reduce the amount of snow and ice buildup while maintaining traction.
Our M8 tests in Colorado showed that with its reduced weight, refined clutching and EFI calibrations, the M8 gave up nothing to the higher horse RMK Dragon and Summit 800s. We're not BS-ing you. While the '07 M8 was shipped to dealers with its primary clutching wrong for high-altitude runs and its springs and weights were too light, the new '08 is fine. It has heavier weights - 73 to 75 g - and the motor wills itself to every driver demand.
However, the M8 needs to continue losing weight and gaining power to stay competitive. That said, the M8 has deep snow, boondocking and stump jumping capabilities that have consistently set the standard for others to match.
Ski-Doo Summit REV-XPSki-Doo may have saved a few marriages by trimming 40+ lbs. from its mountain sleds. The amount of money a sled owner would had to have spent to cut that weight from a sled easily could have led to divorce or bankruptcy.
What Ski-Doo did is nearly beyond comprehension. Chris Ruske, Godfather of the Summit R&D team, is driven in his mission to create the best, strongest, lightest mountain sled, and he may just have done it.
Chiseling weight off the Summit Everest gives it a power-to-weight ratio of about .35 horsepower per pound. Dry weight is 439 lbs., and AmSnow dynoed the engine last year at 155.7 hp. Mountain riders disdain weight and look for creative ways to dump it without hurting structural integrity. Our sleds must withstand mountain punishment. The 2007 REV Summit X-RS proved that structural rigidity was important. It couldn't take a front end smack without damaging the "flying nun" (bulkhead) and the tunnel behind it. Repairs were expensive.
That doesn't look to be the case here. Ski-Doo reduced chassis weight while strengthening the chassis by a kicking 37%, which should keep the nay-sayers quiet. The XP is more than a light seat, hood and exhaust system combo, it is an extreme makeover. Here's a quick list of changes and improvements:
-Lighter SC-5M rear suspension
-Ergos that allow the driver to place his/her feet 8 inches farther forward than original REV chassis
-Front suspension with Ackerman steering (where the inside ski turns sharper than the outside ski)
-Strong, ultra light, body & hood
-Light, durable seat
-Deep center of gravity
-Light & Hulk-strong "flying nun" (bulkhead)
-Driven clutch that sits nearly vertical under the primary clutch
-Simple controls on the handlebars
We can't say how this will handle in the really deep powder, but what we did notice, is that this lightest of the mountain sleds felt heaviest through the bars; we aren't 100% sure why yet. In the powder though, this may be completely different. We'll know more after we get some saddle time this season.
SummationFirst, we're sorry we can't give our mountain readers our final impressions on these new sleds because we haven't been able to fully test them in their true element - deep powder. Crazy Colorado snow! However, from the tech aspect and riding we DID get in, we are duly impressed with this season's crop. The RMK 800 163 Dragon pushed our wow button the most and has us wishing for winter.
The FX Nytro MTX hits the sweet spot and should not be shuffled to the back of the class. It's a fine product and deserves attention. Remember it lost 90 lbs. compared with the sled it replaces.
Cat refined its M8 by dropping about 10 lbs., making smart decisions on clutching, front and rear suspension tuning and front turning radius to help rejuvenate the M8.
Then Ski-Doo, my, my, we are still punching the numbers into our calculator. Yes, we know what they did, but, uh, how'd they do it? We are impressed; smart R&D guys at BRP designed a sled that NASA could envy.