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2011 VIPER DIAMONDBACK Motorcycle News

Feature Motorcycle Reviews Harley Reviews Production Customs

2011 VIPER DIAMONDBACK Motorcycle News


It’s all about size. I regret to inform you that no matter what your girlfriend or wife tell you, size does matter. Now, can you imagine what your honey would say if you came home with 152″ between your legs? Well, thanks to the Viper Motorcycle Company and its Diamondback super cruiser, every man can now get a 152″ augmentation for less than 40 grand.

Let me digress for a moment. I was first exposed to Viper and its short-stroke, air- and oil-cooled, 45-degree V-twin 152″ billet aluminum engine while visiting Vegas in 2007 (reviewed May 2008). Back then, I was impressed with the overall package this small manufacturer from Minnesota was producing. Since then, Viper has teamed up with race engine manufacturer Ilmor Engineering to refine and produce its latest incarnation of the 152 motor. Basically, what this collaboration has done is make an already good engine even better.

My latest Viper rock star experience occurred while attending the 70th anniversary Sturgis Rally this past August, where I had the good fortune of pounding on the 2011 Viper Diamondback for the week. From the start, it quickly became evident that even though I was at a major rally with hundreds of thousands of motorcycles around, there were few V-twins on the road that had more cubic inches then I did. Those that did were usually customs with one-off engines, definitely not a refined production motorcycle like I had between my legs. The best part of my testing a bike in Sturgis and its surroundings is the fact that it was easy for me to use the vehicle in a variety of different riding scenarios. What I found with the Diamondback is that it didn’t matter if I was riding through the twisties of the Black Hills, dealing with traffic jams on Main or Lazell streets, or ripping it down the interstates. This bike was versatile and could do it all even with a 152″ power plant. The bike was so reliable that I even went as far as using it in a painfully slow speed group tour called the annual Mayor’s Ride, and through it all, I can honestly say that the Viper never once misfired, missed a shift, or overheated.

Even at a glance it’s hard to overlook the over-square gem of an engine Ilmor and Viper have created. It’s loosely based on an Evo mill and features honed steel cylinder sleeves with forged pistons and a 4.70″ bore by 4.375″ stroke. Four plugs and advance ported heads allow this engine to efficiently burn fuel, which I found to be flawlessly delivered by a Mikuni HSR45 flat slide carburetor. Air intake is through a chrome billet air cleaner with K&N air filter while tuned pipes take care of the exhaust. An Ilmor-designed dry sump oiling system does a great job of keeping things cool. So much so it seems like this 152 runs cooler than some stock 96ers I’ve ridden.

When all is said and done, Viper claims this power plant produces 130 hp and 160 ft-lbs of torque, which my seat-of-the-pants dyno has no reason not to believe.
Further inspection reveals that the engine is cradled in a proprietary 38-degree raked Viper frame using a patented rubber engine mounting system. It’s unique in that it is a center-mounted engine/transmission system that uses an eye-catching seven-piece chrome billet swingarm that is not rubber mounted. Mix in the Marzocchi inverted, adjustable cartridge front fork and an oil dampened, on-the-fly, adjustable air-ride rear suspension, and the Diamondback has a smooth, almost vibration-free ride, which is amazing considering the engine’s displacement. In general, short-stroke engines tend to rev a bit higher, but that is not an issue here since you have a BAKER RSD, six-speed overdrive transmission and gobs of horsepower and torque available.

The overall length of the Diamondback is 100″ making it 5″ longer than a Harley Rocker C and 6″ longer than a Dyna Wide Glide. This bike’s wheelbase is 71″, which is again 2″ longer than a Rocker C and 3″ longer than a FXDWG. The dry weight of the Viper I rode was 645 pounds, which is just about the same as a Dyna Super Glide. The whole package rolls on a 130 front and 260 rear chrome billet wheels that feature single four-piston brake calipers front and back. The forward controls are adjustable in seven different positions, easily accommodating riders of many sizes, including my 6’2″ frame. All this translates into a stable motorcycle that is comfortable and easy to ride. Note that I did feel a high-speed wobble around 110-120 mph. That said, I believe that since I was on a practically brand-new bike, a simple break-in service and a retorque of the front neck would address this wobble, making it a nonissue.

The Ilmor Engineering and Viper collaboration has made owning a 152″ monster motor bike civilized. With a Diamondback in your garage, going for a thrill ride is as simple as turning the key, pressing down the two compression releases, flipping the petcock to On, squirting a couple of twists of gas into the carburetor, and hitting the starter button. Then, after letting the billet motor warm a few minutes, you’ll be on your way. If you ask me, it doesn’t get any easier, especially for a large billet engine. The best part might be that once you’re on the road, it’s up to you if you want to take a mellow ride around town or do some hell-raising across the countryside. Whatever you choose, this bike can deliver.

So if you’re a Harley rider who simply feels inadequate with 96″, 103″, or maybe 110″, try putting a Viper between your legs. Trust me, you won’t regret dropping the cash. Hopefully, your girl will appreciate it, too. AIM

NEW BIKE TEST By Joe Knezevic

As seen in the April 2011 issue of American Iron Magazine