Timbersled Snowbike Conversion

But what if that high-tech 450cc thumper or 250-300cc ringy-dingy could be your sled? You know, take the power of your dirtbike combined with its light weight and the kind of maneuverability that the typical 400-plus-lb sled could only dream of having? Well, if you are a dirtbiker who suffers from SAD, there is a prescription for you and your bike: You can turn it into a “snowbike,” and free up some cash and some garage space by selling your dedicated snowmobile to someone else who doesn’t mind parking it in the corner for 6-8 months out of the year.

There are a few snowbike kit manufacturers in the marketplace today (see sidebar), but Timbersled has already earned a solid reputation for developing snowbike kits that allow hard-core dirtbike riders to extend their moto passion into all seasons. Timbersled wasn’t the first manufacturer in the game, but they’re one of the best when it comes to developing a durable kit that’s built for serious boonie bashing. We first wrote about the Timbersled Mountain Horse snowbike kit for Off-Road.com in October 2011, and Timbersled has been going strong ever since.

Timbersled Products, Inc., founder Allen Mangum began designing and testing the Mountain Horse kit about eight years ago. Originally, the rear suspension was a narrowed-up snowmobile rear suspension, which Timbersled designed and built for long-track snowmobiles. Called the “Mountain Tamer” back then, it was based on a proven aftermarket (non-OEM) rear snowmobile suspension that found popularity among mountain sled riders. The challenge Mangum and his design staff had to overcome in adapting the design for motorcycle use was how to drive the track from a front horizontal drive shaft rather than stretching the drive chain to a horizontal drive shaft located at the rear. Mangum and his trusty staff figured out the problem, and their new design began to compete with the 2Moto snowbike kit just as the snowbike movement began to blossom. The market potential was enough to catch the eye of powersports industry giant Polaris, which acquired Timbersled in April of 2015.

From Dirt To Snow: 2Moto Snowbike Review

Now as then, Timbersled continues to devote considerable R&D time and resources into upgrading its Mountain Horse kits; the latest version is vastly improved over earlier generations. Over the past few years, Timbersled has dialed-in the Mountain Horse’s overall length, shocks, and switched to a more convex track. For 2016, there are three basic kit models offered with a number of options available within each kit.

Timbersled Short Track [ST] Conversion Kit ($5,300 USD)

The ST is Timbersled’s most versatile kit. It works with 250cc four-strokes, and 250cc or 300cc two-strokes as well as four-stroke models, and it is even claimed to be able to withstand power from anything up to and including high-horsepower turbocharged engines. The ST is also claimed to be capable in deep powder as well as hard-packed snow.

Timbersled Long Track [LT] Conversion Kit ($6,000 USD)

The LT’s forte is deep, powdery snow, such as is found in Western mountains. The LT is also recommended for riders weighing over 220 lbs. because its longer track delivers better floatation than the ST.

Timbersled Snow Cross SX120 ($5,800 USD) and SX137 ($6,500 USD) Conversion Kits

Originally developed for purpose-built race machines, the SX kit is designed to be more responsive than the LT or ST, and they also offer the most suspension travel. The SX’s 2-inch narrower (10.5-inch) track, chassis and suspension geometries deliver more maneuverability for snowcross tracks. As its model designations imply, the kit is available in either a 120-inch or 137-inch track length.

The Timbersled Mountain Horse kit can be installed on most popular dirtbike models, including but not limited to Yamaha, Kawasaki, Suzuki, Honda, KTM, Husqvarna and Beta, and it’s actually surprising just how well-suited the typical 450cc four-stroke dirt burner is when it comes to making the conversion from dirtbike to snowbike. The rev-happy, electronically fuel-injected (EFI) Singles have more ample torque and horsepower to sling the Mountain Horse track with ease, even at high altitudes.

Two-stroke dirtbikes such as the KTM and Husqvarna 300s can also muster the power to work with the Mountain Horse kit, but, as the old saying goes, there’s no replacement for displacement. It should also be noted that electric-start models are also preferred due to the fact that solid footing isn’t always available if you should go down in deep snow and need to restart your stalled snowbike.

Timbersled’s Convex rear suspension design is a big reason for its success. Over the years, the design has evolved to the point that it mimics, as best as Timbersled can engineer it, the travel, feel, handling and control of a standard dirtbike rear suspension. New for 2016 is and optional Timbersled Suspension Strut (TSS) that Timbersled claims to add an even more nimble dirtbike feel, maximize power transfer to the snow more efficiently and is more sensitive to terrain and snow consistency changes. According to the company, the TSS is the single largest improvement that’s ever been made to the Mountain Horse Snowbike system. “It is a total game changer. It adds a second point of suspension to the stock motorcycle swingarm pivot point by adding a custom-built shock that is designed to work in conjunction and complement the new Convex 2.5 long-travel rear track suspension.”

Installing the kit is neither difficult nor permanent – it’s a true bolt-on operation. The rear suspension replaces the swingarm, and a “tunnel extension with snowflap” replaces the rear fender. A wide Simmons ski, designed exclusively for the Mountain Horse kit, replaces the front tire. The track, designed by Timbersled and built by Camoplast is specific to the Mountain Horse in terms of lug pattern, pitch and lug duometer (a ratio of lug stiffness at base and flexibility at tip) is unique to the snowbike. The lugs are 2.5 inches long.

When I first rode a Timbersled Mountain Horse, I found that learning to master the longer motorcycle with a track and ski, only took about an hour. My tutor was Mangum himself, and we swapped back and forth between a Honda CRF450R and Yamaha YZ450F. This past winter, I spent a day on two Yamaha WR450Fs at the exact location where Mangum introduced me to the sport three years ago. Riding a 450cc dirtbike in the backcountry is something that will be familiar to most of our readers, but replace the rear wheel with a 120- or 137-inch long, 12.50-inch wide track that places 1500 or 1712.50 square-inches of tread on the ground, and replace the front wheel with a ski that is almost as wide as a snowboard, and it’s an amazingly different and very cool experience.

However, riding a snowbike on a hardpacked trail is not fun at all because a snowbike is not nearly as responsive to standard motorcycle steering inputs when the snow is firm. With its long track and ski, the bike’s steering geometry is significantly altered. The track’s width resists the usual tendency for the bike to lean into corners, and its length causes the bike to understeer in concrete-like snow. Thus, the closer the backcountry is to the trailhead, the better. The ST kit works best with snow depths of 1 or 2 feet, but the LT kit can easily handle 3 feet of powder, especially if equipped with the optional TSS kit.

Once off the trail or out of the parking lot, the Timbersled Mountain Horse becomes what it is, a light and slim “snowmobile” with a single ski and narrow track. So, what’s it like? Twist the throttle, bang into first, then second and third and let it float. Don’t expect explosive four-stroke or two-stroke power like a dirtbike. Instead, you’ll feel gentle, even acceleration that feels more like it comes from an electric motor than an internal-combustion engine. You’ll also rarely need to row the gearbox. Most people ride their snowbikes using just second and third gear.

Handling is also different. In powder, a snowbike is a very fun and forgiving ride once a rider adapts to its balance and steering characteristics. For starters, he or she quickly learns to resist standing on the footpegs most of the time. There are times to stand, but it is easiest to learn to lean and jockey the snowbike when seated. You simply sit, relax, and give the bars gentle inputs to initiate a turn, with a dropped inside shoulder helping to point you where you want to go as you pick your cornering line. Do that, and the snowbike will obediently turn right or left, but you must remember not to turn too sharply or chop the throttle, or down you’ll go. There really is no such thing as freewheeling with a track. Remember that the throttle is your friend, as a snowbike will stick to powder-laden mountain terrain like a magnet on steel.

The long-travel front fork and long-travel rear skidframe prevents the bike from porpoising and does such a good job of taming what few bumps you’re likely to encounter that arm pump is virtually non-existent. Still, a snowbike handles whoops rather well. Instinctively, you’ll want to stand, but stay seated and let the two suspension systems manage the impact energy. There’s no teeth-rattling feedback through the bars or seat, but rather just a gentle rolling feel as the suspension does its job.

And sidehilling a snowbike is all but guaranteed to twist the senses. Have a 30-degree or greater slope in your way? No problem. First, scope out your line, and lean the bike into the hill as you hit the gears. With momentum to keep the snowbike upright, the ski and track quickly builds a shelf. Snowbikes don’t wash out the front or rear end.

Most people can expect to spend a couple hours learning the different riding style that the snowbike requires. Allow it to teach you, and you should be able to master it. Snowbikes want – no, beg – to be ridden.

One other thing, and this is critically important: If you are planning to ride a snowbike, become avalanche smart and make sure to carry the proper equipment to protect yourself, including a beacon, a probe, a small shovel and an avalanche air bag (a.k.a. an avy bag). Look to Klim and MotorFist to outfit your body.

There simply is no reason to let SAD takeover your life. A snowbike is an excellent prescription. Sure, it may be a little colder … okay, a lot colder riding climate than you’re used to, but dress for it and you’ll be having too much fun to care. And it’s a better and healthier feeling than anything you could get from big pharma.