Denny Berg's Swan Song: A Custom Cobra Royal Star

In 1997 customizer Denny Berg decided to put away the wrenches after more than 25 years of customizing, but look at his going away present.

Cobra Royal Star
Denny Berg’s may have put away the wrenches, but this custom Cobra Royal Star was his swan song.Fran Kuhn

Denny Berg has built all kinds of customs since 1970. Starting his career as a tuner, Berg quickly moved to producing cafe-racer customs, ultimately building two world championship race bikes before moving on to custom Harleys. Although he says he learned a great deal in his years customizing Harleys, Berg gave up his custom business when he felt he was losing his edge. After a stint as R&D Manager at White Brothers, Berg felt the old itch return. This time Berg had a two-pronged approach: he restored bikes and built full-blown customs.

Since we’ve featured Berg’s bikes in the Summer ’96, December ’96, and February ’97 issues of Motorcycle Cruiser, regular readers are already familiar with bikes built by his company, Time Machine. However, Ken Boyko, of Cobra fame, has built a working relationship with Berg over three years and ten bikes (plus consulting work on about ten more Cobra bikes). When Boyko contracts Berg to build a custom bike, they sit down and discuss the theme of the bike and how they want to go about achieving it. Both of these men, who clearly enjoy building custom bikes for the sole purpose of creating motorcycle art, say the process is not an easy one but one they savor.

Cobra Royal Star engine
Berg wanted Eleganza’s engine to look like an old airplane engine. The chromed, smooth valve cover hit the trash while the real valve cover received the loving attention of the polisher. The bolt-on cooling fins had almost an inch machined off.Fran Kuhn

This Royal Star, dubbed Eleganza by Boyko when he saw the completed product, was one of three bikes Boyko hired Berg to build for this year’s Dealernews Powersports Expo in Cincinnati. Of the three bikes, Boyko says that Eleganza is his favorite, and only when viewed from a distance (to keep from being distracted by all the nice detail work) can the bike be truly appreciated. At the time Berg was building Eleganza, neither he nor Boyko knew that Berg would decide to retire shortly after completing the project.

Although the costs and the stakes are high in building big-budget customs, Berg claims that when he gets into a project, he’s just a kid putting a model together. Nonetheless, in the midst of building a bike, Berg feels all he can see are the problems and challenges requiring attention. Keeping track of what the finished product will look like when fit together can be difficult when everything is apart. Immediately after putting the final touches on a project, Berg says he looks at the bike and still sees all the places he could have done more or done it differently. Once six months to a year have passed, he often feels a flash of “Wow, that was pretty neat,” when he sees one of his creations either in the flesh or in pictures. Only then can he appreciate what he’s created, like he’s seeing a bike for the first time.

front wheel
The first set of the ingeniously self-balancing Hallcraft wheels for the Royal Star now live on Eleganza. Formerly located on a YZF 750R, the six-piston calipers look as good as they work on Braking’s full floater discs. The stock radiator shroud was painted with Hammertone paint to give it the look of hammered metal.Fran Kuhn

Polishing the Jewel
Every project begins at the same place, tearing down the stock bike to the chassis. Once the Royal Star was apart, Berg took what many customizers would say was the heretical step of stripping all the chrome off the engine cases and sending them to California Polishing. Why polish? Berg feels that chrome hides the individual characteristics of different metals. Stainless steel acquires a gold patina as it ages while aluminum shows off its alloy heritage in a deep lustre. Simply put, Berg finds polished metals "more interesting" to look at. Consequently, the engine sports polished valve covers and cooling fins. Before the fins were polished, they were machined to a uniform length with some fins shedding as much as three fourths of an inch. Many other non-engine parts, such as the fork covers and master cylinders, were also polished.

The dot in the middle of the grip is the micro-switch starter button. A similar button on the left grip operates the horn.Fran Kuhn

The engine’s modifications weren’t just skin deep. While the valve covers were at the polisher, V-Max cams and valve springs snuck into the mix. Further breathing exercises came courtesy of two Mikuni Solex 1970s-spec side draft carburetors (often seen gracing the engines of Kawasaki Z1s of the era). Since the left and right carbs are connected with a balance tube, anyone lucky enough to be looking at the carbs when the throttle is cranked wide open is treated to a view of the world on the other side of the bike as viewed through the intake system. Fuel flows to the carbs courtesy of a Pingel high-flow petcock. Jetting the hopped up mill proved to be arduous because jets for these vintage carbs were difficult to locate. The combustion by-products make their way out of the engine through ultra-long 2.25-inch diameter pipes, hand-bent by Boyko’s partner, Tim McCool. (Boyko says the pipes may be Cobra production items next year.) Rounding out Berg’s go-fast modifications, a V-Max ring and pinion, which have one less tooth each and result in slightly lower gearing overall, were dropped into the rear drive for “a little more get up and go.”

While the carbon-fiber covered OEM headlight bracket looks trick, it’s the little touches that make Berg’s work stand out. The stock fork covers were polished and the headlight bucket received a coat of paint and a Cobra visor. The lens sports a Berg-trademark chrome button.Fran Kuhn

Old-Style High Tech The frame beautification project began with sand blasting and smoothing the welds. The plastic panels around the steering head were replaced with 18-gauge steel that was molded, welded, and smoothed for a clean, seamless front end. Out back, the plastic side panels were exchanged for more 18-gauge steel. This time, Berg's inspiration came from the floating grills of Italian touring cars of the '30s. The steel was hammered and smoothed to perfection. Since the seat would be bolted directly to this shapely perch, the stock seat was covered with leather and a new underside of the seat was fabricated from 18-gauge steel to better connect the lines of the frame with the tank Berg had planned.

Berg says he wanted to modify the lines of the Royal Star while still keeping much of the look intact. For example, the carbon-fiber front fender was made from a mold of the stock Yamaha fender. However, before making the mold, Berg filled out the ridges that run down the sides of the fender with a generous application of Bondo followed by shaping and block sanding. The rear fender underwent a similar process, only more so. The rear fender was lengthened by five inches and the sides were lowered so the modified radius could more closely match the shape of the larger wheels Berg wanted to fit to the Royal Star. To avoid cluttering the fender, a set of Drag Specialties clearance lights (which could also work as turn signals if Berg had included a switch on the handlebar) were formed from Bondo into the bottom of the fender. A Cobra license plate holder and the stock fender rails highlight the sano fender.

Low-flying birds beware! Straight from the 70s, side-draft Mikuni Solexes open wide and say “ah.”Fran Kuhn

Readers may be surprised to find out how much Berg likes to use Bondo (which is primarily thought of as a metal repair material) when building a custom, but he explains that the free-form material gives him the total control he needs to let his creativity flow. Berg’s modification of the tank provides a prime example of how he uses this miracle tool. First, to clean up the top portion of the tank, the stock gas cap was tunneled in flush with the tank’s surface. Next, the end of the tank was stretched out to accentuate the long look Berg wanted Eleganza to have. Since Berg says he has always hated the seam on the bottom edge of Japanese cruisers’ gas tanks and since he worried he would compromise the integrity of the tank by cutting the seam off and welding it flush, Bondo, built up to a half inch thickness, enabled him to hide the ugly seam and sculpt the underside of the tank to suit his tastes. A strip of carbon-fiber finished off the modifications to the tank.

rear wheel
Eleganza’s fender was extended by five inches and supported by a sub-frame attached to the swingarm. Lowering the rear suspension by two inches, and adding the mile-long straight pipes, accentuates the elongated appearance of the bike.Fran Kuhn

Carbon-fiber makes an appearance in several other places on Eleganza. Instead of fabricating a new headlight mounting bracket, the stock bracket was overlaid with carbon-fiber. The speedometer nacelle, however, is a carbon-fiber duplicate of the original equipment and bolted into place.

With all the effort put in to the carbon fiber treatment of the bodywork, Boyko and Berg certainly weren’t going to cover all their handiwork with paint. Since they wanted a rich color scheme (but not loud or bright) and they wanted the paint colors to integrate seamlessly with the carbon fiber, they scoured books of paint chips to select their colors. Finally they decided to tie the color scheme together by choosing a Lexus champagne color that closely matched the gold highlights in the carbon-fiber. Damons Motorcycle Creations was enlisted to use the selected colors to create an art deco paint scheme that would give Eleganza a vintage feel while still strutting the future tech carbon-fiber. The final product consists of pearl bamboo (a match to the Lexus champagne color Boyko originally envisioned) background color with overlaid waves of bronze and pearl cranberry with a Cobra logo on the sides of the tank. While the paint job may look simple, the folks at Damons were given a few challenges to pique their interest. In order to produce the coveted mirror finish on the tank, about six layers of clear coat, each followed by block sanding, were lavished on the tank until it was impossible to tell that the carbon-fiber was inlaid.

The stock speedometer housing was duplicated in carbon-fiber while the Yamaha gas cap sinks flush into the tank’s surface. Note how the brake, throttle, and clutch lines slip through the steering head to keep the handlebar area uncluttered.Fran Kuhn

Ground Floor Most of the modifications to Eleganza— lengthening the tank, bolting on mile-long straight pipes, extending the rear fender while keeping the now dwarfed-looking stock fender rail, and attaching the rear fender to the swingarm—were directed toward enhancing the already long, low lines of the Royal Star. Copying a trick used by hot rodders, Berg "slammed" Eleganza two inches closer to the ground through the use of Cobra's fork lowering kit and his own rear linkage. Other clever tricks, like altering the radius of the rear portion of the front fender, fool the eye into thinking the bike is even longer and lower. Similarly, to give the appearance of lowering the frame even more, the stock cast wheels (16 x 3.5 inch front and 15 x 4.0 inch rear) were replaced with Hallcraft's 80-spoke wheels. The large 17 x 3.5-inch front and 17 x 5-inch rear wheels, when combined with Dunlop's low-profile 160/60-17 tires, help make the frame appear to hang lower. Hallcraft's wheels' special vacuum silicone sealing allows tubeless tires to be used with the spoke rims, and the wheels self-balance themselves, utilizing an endless rubber tube partially filled with mercury. As the tire rotates, the mercury constantly adjusts itself to achieve a perfect balance.

The stock fuel tank was lengthened and had the ugly seams removed from the bottom. No wires or switches mar the pilot’s view from the cockpit. Lots of clear coats and buffing keep the finish smooth over the inlaid carbo-fiber.Fran Kuhn

While other builders might be willing to reassemble their custom after completing the above work, Berg went one step further. In his own words, “I hate seeing customs with their wires and cables hanging out everywhere. That drives me nuts!” Every wire, hose, and cable was meticulously hidden. The wiring harness runs up the left side of the frame, and most electrical components were relocated under the tank. All stock handlebar switches were bypassed save the horn and starter buttons whose wires were routed through Berg’s scratch-built handlebar from their locations in the ends of the bar. Only the throttle cable and hydraulic lines are visible without up-close inspection, and they slip neatly through the steering stem. The only part of the bike that Berg couldn’t dress up was the battery, which he tucked under the seat. A smattering of Cobra bolt-on parts (bolt covers and pegs) completed Eleganza.

The “Eleganza” enhances the long, low lines of the Royal Star by not only being lowered two inches, but with little tricks like altering the radius of the rear portion of the front fender to fool the eye into thinking it’s even longer and lower.Fran Kuhn

Now that he’s closed his business and moved away from the megalopolis, Berg can look comfortably back on this project. When asked what he’d change on Eleganza if he could, Berg responded, “It would be parked in my garage, not someone else’s.” Then becoming serious, he said, “Building is a journey, not the end product. The destination is not important.” With such a passion for creating motorcycles, we can’t help but wonder how long Berg will be able to keep his tools in the box.

This article was originally published in the August 1997 issue of Motorcycle Cruiser.