AD Boivin Snow Hawk

New models

March 2003 Feature We review the orange attention getter Viewed 5161 time(s)

Since the Snow Hawk is such a different machine that anything typically seen on snow, we expected it to handle as such. When you turn a sled, it rolls to the outside. When you turn the Hawk, it leans in and bites.
The Hawk is based on a swingarm-type rear suspension (AD Boivin's Expert X) and a pair of Paioli motorcycle forks. Though the handlebars are nowhere near the top of the forks, like you would find on a motocross bike, the overall design and concepts are similar. AD Boivin wanted to build a snowmobile that handled like a dirt bike. Did it succeed? Yes and no.

What engine does the Hawk use?
The same 503 Rotax twin-cylinder, fan-cooled engine you would find on a 2002 Summit 500. The 503 is relatively light when compared to its liquid-cooled counterpart.

How is the power?
The 503 makes an estimated 60 horsepower. For beginners and riders who've never ridden a dirt bike, it's perfect. After you've put a dozen hours on the Hawk, however, you'll be crying for more power. After all, the Hawk weighs 350 pounds. A 500cc two-stroke dirt bike weighs 245 pounds and makes nearly the same amount of power. So it's easy to see why some riders might find the crossover a little hard to get used to.

What is the response like?
Very crisp. In fact, since the Hawk runs premix fuel, the carburetion tuning is much more noticeable than on an oil-injected sled. The Hawk's twist throttle (as opposed to a thumb lever) suits it perfectly.

What carburetors does the Hawk run?
The Hawk uses two Mikuni 34mm carburetors.

What about the exhaust?
The Hawk uses a single tuned exhaust, with a nice, pipey note to it. A pipe builder could possibly shed some weight with an aftermarket exhaust, but not much. There might also be some power available in there.

What clutching does the Hawk run?
The drive clutch is a centrifugal force clutch called the IBC Power Block. It operates much like a typical clutch. It's just smaller and enclosed.
The secondary is an IBC Formula clutch, and runs a cam helix like the sled you ride. It uses a drive belt, though changing it can be tricky.

Does it have a chaincase?
No. It uses a belt drive system similar to Crazy Mountain's design. Since the secondary clutch is mounted above the primary rather than behind it, the center-to-center distance between top and bottom gears in the drive system is much longer than typically expected. So the cog belt is very long. The system also uses a central tensioner wheel.

What does it use for brakes?
The Hawk's brake system is awesome. It uses a Brembo dual-piston caliper and a large 175mm disc, mounted on the driveshaft.

Are those motorcycle forks on the front?
Yes. The Hawk went to Italy for its front suspension. It uses Paioli 46mm inverted forks. The forks have compression adjusters on the bottom of the legs and rebound clickers on the top caps. They also have air bleed screws in the caps. AD Boivin's own version of a triple clamp connects the forks to the head of the chassis. The forks are one of the greatest contributors to the Hawk's bike-like feel.

What's under the rear end?
When AD Boivin first got into the snowmobile business, they started making rear suspensions based on a swingarm design. That original concept has survived the development process and now graces the Snow Hawk. It's called the Expert X, and uses two side-by-side Kayaba coil-over shocks. The tail end of the skidframe's swingarm mounts to the slide rails at the same location a bike's rear tire would touch the ground. The other end of the swingarm mounts to the center of the Hawk's chassis, rather than right beneath the rider. This design transfers bump energy to the center of the chassis rather than to the rider.

How does it handle?
Like a stand-up watercraft. Forget all you know about riding snowmobiles. Guys with bike riding experience who've never been on a sled will likely adapt to the Hawk more quickly than hard core sledders. There are a couple of rules to riding the Hawk. First off, the faster you go, the more stable the Hawk is. The more gas you give it going through a corner, the easier it will come out of a turn. And if you want to turn in the powder, don't turn the ski. Just lean it over and grab the throttle-just like a Jet-Ski.
The front end handles bumps well, but not the constant washboard type. The Hawk is best suited for untracked snow where it can sink down and carve in.

How's the fun factor?
Very high. Despite the Hawk's power and weight issues, it is a blast to ride. Once mastered, it can be thrown around and maneuvered however you want it. It's quick off the bottom, cruises comfortably, and induces quite a rush. The best advice we can offer is to talk a couple of buddies into getting a Hawk, too. The Hawk is much more fun to ride when there's someone else on one to dice with.

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