2015 Yamaha SR VIPER S-TX DX: The Do-All Crossover Viper

Here we are at year two of the new Yamaha SR Viper series and we already see Yamaha expanding their offerings of SR Viper models for 2015. This time we have the new SR Viper S-TX DX, which is a performance crossover sled fitted with a 141” track length that expands the cargo capability of the Viper family, along with giving us the option of having a two-up sled. The added track length gives us more room to work with and adds even more stability, along with more flotation as well.

At the heart of the new S-TX DX is the same Genesis 3-cylinder 1049cc engine we used to call the Nytro engine, but now more affectionately called the SR Viper motor. The S-TX DX comes fitted with a much taller windshield for more rider protection from the elements, a nice feature to have come standard instead of having to spend even more money for the windshield a long-distance rider wants and needs.

Up front we find coil-over HPG shocks and a new set of Yamaha’s Deep Keel Tuner skis. This combination is really calibrated for comfort and tracks straight with reduced steering effort, giving a nice package for crossover style riding. The nose weight of the four-stroke engine gives us adequate ski pressure so pushing is not an issue in the corners, and the dual keel dual runner design of these new Tuner skis gives us straighter tracking, even in rutted trail conditions.

Compared to the SR Viper LTX models we have to choose from, the S-TX DX comes with a 141” rear suspension and track length instead of the 137” length of the LTX models. Yamaha calls this their Dual Shock SR 141 rear suspension. It features a Fox FLOAT3 air spring shock on the rear arm combined with an aluminum-body HPG shock on the front arm. With the Fox FLOAT air spring shock absorber on the rear arm there are no torsion springs, so all rear arm preload adjustments are now done with an air pump. There are two ways of looking at this; if the shock has a bunch of ice and snow on it, this makes preload adjustments a bit more cumbersome. But, the progressive rate of the air spring gives us far more preload capacity and a far more rising curve to the spring rate at the end of the suspension travel, so hard bottoming is really very difficult. This is a good thing for a sled that is designed to be carrying extra cargo and even a passenger and is the real reason the S-TX DX comes with this suspension arrangement, instead of our more traditional torsion springs.

OK, we admit, we have typically not been huge fans of the Arctic Cat 141” rear suspension with the Fox FLOAT rear shock simply because it was more difficult to make preload changes and because it was not as smooth or as compliant of a calibration, especially when compared to the new 137” rear suspensions that were introduced for 2014. But, something is now very different for 2015 on this rear suspension. We suspect Yamaha calibration engineers have been working with Arctic Cat suspension teams on making this arrangement work even better, and it shows. Our initial testing of the 2015 versions of this rear suspension have been far more favorable as the ride quality is more compliant through the chatter bumps. You still have the rising spring rate of the air shock for anti-bottoming, but in the ride zone the shock is stroking better and the result is a marked improvement in ride quality. We also noticed this on the Cat versions of this suspension, so there could be some geometry changes, but more likely it is through improved calibration. It shows.

One of the best parts of this sled is the fact it comes with a 141 x 1.352” Camoplast Cobra track. This design with cupped lugs delivers excellent deep snow performance without compromising on-trail action. Seriously, we have put thousands of miles on this exact track design and absolutely love it. If anything it will wear off the tips of the lugs after a while on hard packed trails so it doesn’t seem to be as durable over the long haul compared to say a Ripsaw track, but for what you gain in traction and loose snow capability it should be a good trade-off. You will be impressed with how well this track works both on and off trail, it is truly the best of both worlds.

A key feature of the S-TX DX is the modular rear bumper that allows integration of a (stock) rear cargo rack, or one of many accessories, like the optional two-up seat that plugs right into the modular bumper design. The stock cargo rack can carry all kinds of accessory cargo bags and can be used at the same time as the drop-on two-up seat, giving you a sled that is truly versatile; you can ride it hard through the bumps, you can take it off trail and have some fun, and you can carry plenty of cargo – with or without a passenger. Like we said, versatile.

Adding to the comfort factor of the longer track and taller windshield is a standard heated seat with high and low settings. When the going gets really cold this is a nice feature to have to help maintain your body’s core temperature, especially on those long distance touring rides.

It is those long rides or high mile seasons that you will most appreciate the durability and consistency of the high performance Genesis 4-stroke engine. This same engine is found in every SR Viper model, and continues to be as solid as a rock. It pulls consistently hard from takeoff to top end. Your thumb cracks the three 41mm throttle bodies that deliver strong performance from idle to wide open, giving you a strong 135 horsepower to work with. Power is smooth and wide, and long term you will be hard pressed to find a more durable engine. Seriously, this engine is as solid and as durable as they come. While other sleds will wear out their engines three times, this one will still be running like it was at day one, so for high-mile riders the S-TX DX becomes even more attractive.

The 2015 Yamaha SR Viper S-TX DX comes in your choice of black with silver accents, or Heat Red with white accents, priced at $13,099.

From the September 2014 Issue of SnowTech Magazine (Aug 2014)

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