There’s been much discussion recently about whether 120-inch sleds should move to 137-inches or follow Cat and Yamaha’s lead to move trail sleds to 129-inches.

Ski-Doo recently announced a limited build 2015 MX-Z Iron Dog with a 128-incher and many riders think this is the way things should go. Here’s our take on the subject.

We’ve been very vocal about our support for 137-inch tracks. The versatility you get with a longer track (but not too long) is substantial and since snowmobiling is about more than just trail riding, it makes sense to have enough floatation to be able to ride in powder occasionally. “Occasionally” is actually the key word here.

You need to ask yourself if the mogul bridging effect of a longer track combined with its slightly slower turning ability is enough of a trade-off to suit your riding style. Remember, those 120’s really can crank it on the trails and in tight stuff, their response and turning effort is very noticeable.

It’s actually one of the reasons we like the concept of a 128 or 129. It’s almost impossible to tell the handling difference apart from a 120 and yet you get considerably more floatation with the extra track.

This is very noticeable on sleds that are already light like the Iron Dog compared to a standard MX-Z. We’ve noticed the featherweight 120 MX-Z works surprisingly good in powder and although not ideal, can get the job done.

What about off-trail slanted crossovers? There’s a strong leaning toward 141-146-inch tracks for freestyle and semi-off-trail targeted sleds. Frankly, we feel the more track there is, the less maneuverability you get.

Longer tracks are flat-out harder to turn. We like the 141 because it offers a nice balance of floatation and steering ease, but, with the clutching and engine packages available for today’s sleds you can go heavily into powder with a 137 and not get stuck. True, flat-out hill-climbing is limited on a 137 but it all depends where you’re riding.

There are plenty of choices out there but you need to remember to ask yourself how you really ride, where you ride and then realistically consider the things you like about a sled before you dive in with a track that might be too short – or too long.

We’ve discovered a few tricks getting our Yamaha Viper X-TX riding better and wanted to pass the info on to you while the snow is down.

First, we’ve been really impressed with how well the Arctic Cat Sno-Pros are riding this year. At the same time we were not that pleased with the ride results from our Viper X-TX SE.

To be fair, the X-TX is not targeted as a pure trail sled but rather is more at home riding powder. However, you usually still have to ride trails to get to your fave powder location and the ride can jar all your tooth fillings loose getting there.

Back to Arctic Cat: This year Cat’s engineers changed the damping rates and air pressure settings on a number of their 129, 137 and 141-inch sleds to get them to ride more smoothly. We had assumed the same settings prevailed with Yamaha but they do not. We got out our air pressure pump (the one supplied in the tool-kit) and found that Cat’s air shock settings for the front were 72 to 75-psi, depending on the model.

We then checked the Viper and found the settings were 90 to 95-psi. The front end of the Viper was sitting way high and it was hard to get any static movement in the front shocks at all. When we dropped the air pressure down to 75-psi on the front shocks, the Viper sat a bit lower and there was nice movement in the shocks over washboard and chatter bumps. So far we’ve experienced no bottoming issues.

We didn’t change anything with the center coilover gas shock but checked the air pressure in the rear shock and found it to be 137-lbs. of its maximum allowable 150. We immediately dropped the pressure to 100-psi and got some nice movement in the skidframe.

The sled’s ride was vastly improved and so far we can’t see that it’s negatively affected the deep-snow performance of the X-TX at all. One thing’s for sure: The sled is way more compliant on trails.

We’d recommend these changes for anyone whose body weight goes up to about 200-lbs and if you find you need more air pressure in the rear we’d only bump it up in 5-lb increments to a max of about 115-psi with no rider, sled on the ground. If you’re bottoming out at that pressure level, you need to go on a diet!

BTW: Using this pump is a breeze. Honestly, it doesn’t take any longer than checking the tire pressure on your pick-up and the pump is very accurate. The hardest part is knowing where to begin with pressures and we’ve just supplied that for you.

Good luck.

The all-new Polaris 800 PRO-RMK 155 answers the question: How does Polaris make the world’s best mountain sled even better?

Polaris has raised the bar for Deep Snow performance by building the new 800 PRO-RMK 155 on an all-new AXYS chassis. This new platform, purpose built for mountain riding, features innovative engineering from ski toe to snow flap, and dramatically improves everything that matters to mountain riders.

Built on the patented AXYS chassis, the 2016 800 PRO-RMK 155 provides Deep Snow riders with:

– Instantaneous Lift that allows the sled to pop up onto the snow and stays there
– Rider-Balanced Control that enhances every riding experience
– Immediate Response from a platform that is both rigid and light so it is easy to control and reacts instantly to rider input.

This sled will enable the greatest number of riders to be more successful in the widest variety of conditions.

Polaris is introducing the 800 PRO-RMK 155 in advance of the early-March introduction of the full 2016 Polaris Snowmobile lineup.

MAKING THE BEST MOUNTAIN SLED BETTER

To improve the world’s best deep snow sleds, Polaris developed an all-new AXYS chassis that is purpose built for mountain riding and that dramatically improves everything that matters to mountain riders:

– Instantaneous Lift

– The sled pops up onto the snow immediately due to:

– The patented, raised AXYS chassis, which increases clearance & reduces drag
– New rear suspension design
– Polaris-exclusive track design
– The more powerful 800 H.O. engine that is quick-revving and spools up faster to generate lift.

Rider-Balanced Control

– The patented, raised AXYS chassis delivers the RMK’s legendary perfect riding position.
– The revised rear suspension increases control & delivers a more compliant ride.
– Compact body design keeps weight – and control – on the skis and track.

Immediate Response:

– Rigid chassis + redesigned suspension efficiently deliver rider’s inputs & power to the snow.
– The chassis is stronger, more durable – and lighter.
– 408 lbs.: The PRO-RMK is the world’s lightest mountain sled.

The light weight makes the sled more agile and easier to ride – especially with the rigidity of the AXYS chassis. How easy is it to ride? The 2016 800 PRO-RMK 155 makes it easier to initiate and hold a sidehill, and it is more responsive to rider input than any other mountain sled.

ALL NEW CHASSIS, REDESIGNED SUSPENSION

The patented, raised AXYS chassis improves lift to get the 800 PRO-RMK 155 up on top of the snow immediately, and its increased clearance reduces drag, allowing the sled to stay on top.

This is the lightest and most durable Deep Snow chassis. It maintains the RMK’s renowned rider-balanced positioning so the rider enjoys the ultimate in sled control and insane sidehilling capabilities.

Polaris used advanced design optimization to develop a chassis that is lighter yet stronger and more rigid. The redesigned rear suspension of the 800 PRO-RMK 155 is 3 lb. lighter and 15% more rigid than before.

Rigidity increases responsiveness. With this more-rigid chassis, the sled responds immediately and predictably to rider input. This makes it easier to ride – by riders of all skill levels – and since less input is required, riders are less fatigued and can enjoy riding longer.

A Polaris-exclusive mountain track – the all-new Series 6 2.6″ track – provides the ultimate performance in all riding conditions, including more traction and lift in deep snow.

POWERFUL, PROVEN 800 H.O. ENGINE

The 800 H.O. engine has proven itself in a full season of powering Polaris Trail Performance and Crossover sleds.

It delivers outstanding acceleration and broad mid-range power, with horsepower that’s competitive with class-leading 800 engines.

This quick-revving engine spools up rapidly, providing mountain riders with instant throttle response to generate sled lift. This engine has a high-flow intake and exhaust, and a low-inertia crankshaft that delivers quicker throttle response and lower gyroscopic effect, making it easier for a rider to change directions.

The combination of the powerful 800 H.O. engine and a 408 lb. sled gives the 2016 PRO- RMK the industry’s best power-to-weight ratio.

ALL-NEW FRONT SUSPENSION

The 800 PRO-RMK 155 has a new front suspension to provides more control off-trail and more compliance on-trail.

Innovative features of the new front end include:

– The industry’s first forged aluminum A-Arms, which provide optimal strength and lighter weight
– Taller, design-optimized spindles support the raised chassis and reduce drag
– Premium, lightweight Walker Evans Impact-Extruded Monotube shocks that deliver outstanding performance in a unique one-piece design.

QUICKDRIVE SYSTEM ENHANCES PERFORMANCE

Further enhancing the performance of the 2016 RMK models is the industry-leading QuickDrive Low-Inertia Belt System.

It has a new, lower final drive ratio and 7-tooth drive sprocket for better lift and acceleration.

The system’s strong and robust design reduces operating temperatures and increases shear resistance.

The sled’s industry-leading RMK driveline has been improved for 2016. These upgrades enhance system durability, including a new CVT belt that delivers better performance and a longer service life.

COMPACT AXYS BODY DESIGN ENHANCES RIDE EXPERIENCE

Deep snow riders benefit from the compact AXYS body design because it provides the industry’s highest lean angle to keep the weight on the skis and track – even in the meadows – and it minimizes paneling out.

Ask any avid mountain rider and they’ll tell you that paneling out doesn’t only occur on steep inclines. It is a factor in carving and control at any angle. The confidence-inspiring, compact AXYS bodywork gives riders the greatest lean angle and a larger “sweet spot” in the meadow.

INNOVATIVE AXYS DESIGN

The AXYS design of the 800 PRO-RMK 155 provides riders with a powerful, easy-to-control Deep Snow sled. New premium features include:

– AXYS chassis and compact AXYS bodywork with premium fit and finish
– Proven 800 H.O. engine
– New rear suspension
– New front suspension
– Polaris-exclusive Series 6 2.6″-lug track
– Pro-Taper handlebars that enhance rider comfort and control
– New fenders and consoles
– LED headlights that are lighter and brighter

Proven Polaris PRO-RMK features and benefits include:

– Perfectly balanced rider position
– Rigid Chassis + Suspension
– Technology that delivers lift and response while reducing weight
– Carbon fiber overstructure
– QuickDrive Low-Inertia Belt Drive System
– Extruded running boards
– Smooth-handling, high-flotation skis

THE BEST MOUNTAIN SLED GETS EVEN BETTER

With the innovative engineering of the new AXYS chassis, new front and rear suspensions, a Polaris-exclusive track, and powerful 800 H.O. engine, Polaris has made the best mountain sled – the 800 PRO-RMK 155 – even better.

It dramatically improves on everything that matter most to mountain riders – lift, control, and response – while delivering on the legendary balance that riders have come to expect from the PRO-RMK. All of this makes the 800 PRO-RMK 155 truly the world’s best mountain sled.

Polaris is a recognized leader in the powersports industry with annual 2013 sales of $3.8 billion. Polaris designs, engineers, manufactures and markets innovative, high quality off-road vehicles, including all- terrain vehicles (ATVs) and the Polaris RANGER and RZR side-by-side vehicles, snowmobiles, motorcycles, and on-road electric/hybrid powered vehicles. Polaris is among the global sales leaders for both snowmobiles and off-road vehicles and has established a presence in the heavyweight cruiser and touring motorcycle market with the Victory and Indian Motorcycle brands. Additionally, Polaris continues to invest in the global on-road small electric/hybrid powered vehicle industry with Global Electric Motorcars (GEM), Goupil Industrie SA, Aixam Mega S.A.S., and internally developed vehicles. Polaris enhances the riding experience with a complete line of Polaris Engineered parts, accessories and apparel, Klim branded apparel, and ORV accessories under the Kolpin and Cycle Country brands. Polaris Industries Inc. trades on the New York Stock Exchange under the symbol “PII,” and the Company is included in the S&P Mid-Cap 400 stock price index.

Information about the complete line of Polaris products, apparel, and vehicle accessories is available from authorized Polaris dealers or anytime at www.polaris.com.

We weren’t expecting much when we decided to take our 2015 ZR 4000 RR for a trail ride.

After all, this is a race sled and is intended to do duty in cross-country race events with very little modification required.

We were pretty sure its calibration would be way off for decent pleasure cruising.

This RR Cat differs from its 6000, 7000, 8000 and 9000 kin in that it is more basic and stripped down for race-ready lightness.

For instance, its gauge package is bare minimum, there’s no electric start or reverse available, it sports Cat’s most beefed up racing slide rails and comes with adjustable skidframe shocks with a wide range of compression damping settings.

At the front, Cat has installed its raciest Fox X EVOL air shocks with both compression and rebound adjustability. It also uses a very thin and light 1.25-inch Cobra track (129-inches long).

This low-resistance track allows the 4000’s 500 EFI twin to spin the track easily and it really accelerates fast up to its 80-mph top speed.

All this is good if you’re competing but usually not so good if you want a smooth riding, comfortable sled for all-day snowmobiling. We were surprised.

Wisely, Cat has built-in sufficient adjustability with these shocks that it can be ridden on trails without pile-driving your spine through the top of your helmet.

In fact, when we used minimum settings, it rode extremely well, handling stutters and chatter nicely and when the trails got rougher, even at those low damping settings, the skidframe never bottomed out. This sled has quickly become one of our faves!

Yes, the 500 twin is high-strung, making 84-hp and having a fairly narrow powerband. It’s clutched nicely however, and the sled is completely rideable – especially if you tend to be a bit aggressive with the throttle.

The question is: Is the ZR 4000 RR a good replacement for the former Sno-Pro 500? We say YES in capital letters. This is a truly refined snowmobile that can perform way more than just one function.