In 1996 Denny Berg and Cobra Joined Forces for this Custom Vulcan 1500

Cutting-edge rolling art from the alliance of Cobra and Denny Berg

vulcan 1500, custom
The primary hue of the custom Vulcan 1500 is a sort of metallic version of Kawasaki’s racing lime-green, which gives the bike its name: Green Streak.Fran Kuhn

Sometimes things just don't go as planned. Consider the custom Kawasaki Vulcan 1500 presented here for your inspection. When Cobra Engineering's Ken Boyko and customizing genius Denny Berg sat down to plan it back in late 1996, it was supposed to be one of a set of three machines. The idea was that three different makes of flagship cruisers—a Honda Valkyrie, a Yamaha Royal Star, and a Vulcan 1500 Classic that became this machine—would all get the same elegant, classic treatment. Scheduled to be unveiled at the annual winter industry show, the three bikes were to be a sort of a reversal of the previous year's extravaganza, where four Honda A.C.E. 1100s were taken in four different directions to create four very different machines. For the '97 show, the plan was to turn three different machines into three similar ones.

That plan failed to consider the basic nature of the customizing urge, however. Although the idea was applied fully to the Royal Star (as shown in the August ’97 issue of Motorcycle Cruiser), Berg and Boyko are too creative to press the same mold on three bikes. Once the treatment was successfully applied to one bike, their interest in repeating the same thing twice lost its appeal. So the Valkyrie became a wild hot rod (a little too wild to actually ride, since the custom carburetion never got sorted out), and the Kawasaki became the steely-eyed street fighter you see here.

The engine uses narrower outer cases and gets some other internal parts from the older twin-carb 1500.Fran Kuhn

Treatment was successfully applied to one bike, their interest in repeating the same thing twice lost its appeal. So the Valkyrie became a wild hot rod (a little too wild to actually ride, since the custom carburetion never got sorted out), and the Kawasaki became the steely-eyed street fighter you see here.

“The more I looked at it,” recalls Denny Berg of the inception of the Kawasaki project, “the more it seemed like it should be a burly hot rod. I had a really good feel for this bike when I started. It has those nice, clean, American lines.” And what better way to modify classic American lines than with some classic American muscle?

front wheel
The inverted Ninja fork brought cast wheel dual discs and the two-piston brake calipers to the party.Fran Kuhn

The purposeful, high-performance demeanor of the modified Kawasaki starts up front with an “upside-down” fork assembly from a Kawasaki ZX-7 Ninja sportbike. Berg fabricated special triple clamps, modified the damper rod to lengthen the fork an inch, and sent it to California Polishing to get the sheen. This set one of the themes for the bike, which uses a lot of polished alloy instead of chrome. “Chrome has been done to death,” Berg opines. “Alloy has a warmer feeling. I like the textures and polish you can get this way.” Polished alloy also fits the high-performance disposition of the motorcycle.

The fork brought a 17-inch Ninja wheel, which was also polished along with the dual twin-piston brake calipers, which now pinch Braking USA rotors. Fitted with a Metzeler tire, the wheel is embraced by a modified Cobra fiberglass fender. One of the vast selection of Headwinds headlights with an eye-catching three-section lens was located to give a low belt line. Atop the Ninja fork crown, the stock Vulcan handlebar risers grip an Arlen Ness flattrack bar with its wiring routed inside it. Drag Specialties supplied the handlebar switches, replicas of those on a 1929 Harley. The control cables came from Motion Pro, and they were meticulously routed so they wouldn’t intrude.

The smaller Headwinds headlight and hidden speedo give a lighter, more aggressive look up front.Fran Kuhn

Stock brake and clutch master cylinders also got the polish treatment and were topped with Cobra billet covers. Berg fabricated the stainless steel brake line. With typical Berg flair, he configured the front brake hoses with an eye-pleasing loop around the back of the fender. Ness Grips and throttle match the Headwinds headlight.

The 17-inch cast alloy rear rim is also from the Ninja, but getting it on the shaft-drive Vulcan hub required some fancy machining. “It’s probably the most incredible feature on the whole bike,” Berg told us. Cobra’s craftsmen machined the flanges off the stock Vulcan hub, then machined the Ninja wheel to fit it. The wheel’s spokes were welded to the hub, the welds carefully cleaned up, and the whole assembly sent to California Polishing, which, in Berg’s words, “did a super job.” The stock rear brake caliper—polished, naturally—was hung under the stock swingarm. It uses Braking USA brake pads.

rear wheel
Machining the cast Ninja rear wheel and welding it to the shaft-drive Vulcan hub was a major undertaking.Fran Kuhn

To get the angle and appearance he wanted from the rear tire, he chose a smaller size than is usually fitted to the Ninja wheel. (Before you try this yourself, talk to the tire manufacturer. It can produce handling problems.) With that wide rear wheel stuffed into the chassis, the frame was no longer wide enough and had to be spread out. The rear frame rails were cut off, shortened, and more adjustable Progressive Suspension shocks were fitted to lower the rear of the frame.

We thought the seat area had been lowered too. But that’s an illusion created by dishing the chopped-down fender under the saddle area. The fender itself was created by splitting and widening a Cobra accessory fender. A gray cover with different padding beneath tops the stock Vulcan rider’s seat pan. The taillight came from the Valkyrie Berg was modifying at the same time. It’s a source of annoyance to the Kawasaki guys who assisted Berg and Boyko with the project.

Everyone comments on the speedometer which is set into the top of the tank. Berg put it there because he didn’t want it interrupting the lines on top of the bike. Starting with a stock 1500 Classic tank, Berg frenched in the seams and fabricated sheet metal to fit around the 2.5-inch Drag Specialties gauge. A flush-mounted Goodridge billet filler–cap and a Pingel chrome petcock designed for the Vulcan completed the changes to the fuel tank.

Berg put a smaller speedo meter into the well atop the tank and filled in the area around it with sheet metal.Fran Kuhn

The hot-rod treatment carries through to a nasty-looking engine. In this case, there is more to the engine than just the appearance of power. The motor was torn apart, and Berg mixed and matched components with the older-style 1500 A-model, which supplied the crankshaft, flywheels, and balancer, which are lighter to improve acceleration, and narrower, permitting the use of the A-model side cases, which tuck in a bit tighter and make the engine look unusual even to the knowledgeable viewer. The heads were sent to Mission Yamaha for porting, then fitted with some experimental cams and R&D valve springs. Compression was increased slightly by machining the head, and a Mikuni HSR 42mm carb was fitted (and will probably be offered by Cobra).

In keeping with the hot-rod character of the beast, there is no air filter to obscure the carburetor, which breathes through a velocity stack. Everything worked except the camshafts, which proved to be a bit too radical. New, somewhat milder cams were being readied for installation as this was written. Blasting created a sand-cast appearance to the fins, accentuating the purposeful appearance of the big V-twin. Cobra’s Tim McCool fabricated the two-into-one exhaust system with its pretty head pipes tucked in around the cases. We suspect that Cobra is going to get requests for a similar system from customers.

Berg also played musical gears with the cogs in the four-speed transmission. He used the A-model’s first and third gears and employed the second and third gear sets from the Classic. This put the first three gears close together for hard initial acceleration while keeping the Classic’s comfortable gait on the highway.

The Berg and Cobra project resulted in the steely-eyed custom Kawasaki Vulcan 1500 you see here.Fran Kuhn

The engine is completed with Berg’s attention to sanitation. Removing the air filter left various hoses exposed, so they were routed over the top of the engine out of sight. He also spent time hiding the spark-plug leads as the bike came together.

As with other Cobra/Berg sculptures, the paint was applied by Damons Motorcycle Creations. The primary hue is a sort of metallic version of Kawasaki’s racing lime-green, which perfectly mixes the custom/performance components of the motorcycle’s character. It also gave the bike its name: Green Streak.

A tasteful selection of billet pieces from Cobra’s catalog highlights the bike, including the license-plate frame, nut covers, foot pegs, and controls, which are adapted to the Vulcan’s stock floorboard mounts. As always, Berg devoted considerable attention to routing wiring, cables and hoses out of sight. The detailing is superb.

It’s hard to believe that this bike was supposed to be a smoothly curving streamliner like its companion Royal Star. One speaks of elegance and comfort, the other of street-smart performance, yet they both came from the imaginations and efforts of the same pair of enthusiasts. Which one’s cooler? In our experience, it’s the one you’re standing closest to.