Powersports / Motorcycles / Touring / Gold Wing/ABS / Development
The New Gold Standard - Part 2
The next order of business was generating the optimal quality and quantity of horsepower for long-distance travel without exceeding exhaust emissions or fuel economy parameters. In addition, Aoki would never be satisfied without building in a healthy dose of that fun factor. "The GL1500 engine has an electric motor feel to it. Good power and torque, very linear, but it signs off too early in the rev range," Aoki says. "I wanted more character, more excitement." That is why the new Gold Wing has a more defined power delivery and a free-revving character.
Basic engine configuration is the same, so most of the performance gains come from other sources-the additional displacement; an all-new 50-psi high-pressure digital fuel injection system utilizing two throttle bodies and six injectors; a new electronic CPU that provides two digital 3D fuel injection maps, and one 3D ignition map for each cylinder; and a new exhaust system with a closed-loop emission control and two exhaust catalyzers. This remarkable new engine produces 118 horsepower and 125 lb./ft. of torque while meeting the California Air Resources Board (CARB) 2008 emissions standards.
With the power problem solved, Aoki decided that allowing a socially acceptable amount of six-cylinder attitude to exit the Gold Wing's tail pipes was a vital part of turning up the fun factor. That meant squelching engine noise elsewhere. "The big three noise-producing points on the previous Gold Wing engine were the crankshaft, the AC generator and the transmission," says Aoki. A quieter ACG uses a new damper system that minimizes vibration under acceleration. Recontoured gear teeth make the Gold Wing's five-speed transmission quieter.
Since the new engine would become a stressed chassis member, thus dispensing with its predecessor's rubber motor-mounts, the 1832cc six had to be inherently smoother. Aoki's team was not satisfied with the flat-six's theoretically perfect primary and secondary balance factors. They optimized rotational balance factors inside the engine to reduce high-load harmonic vibration wherever possible. The result is the smoothest Gold Wing engine yet.
It was clear the new Gold Wing's more athletic mission was a perfect match with the aluminum technology perfected through generations of Honda Grand Prix racers, sport bikes and motocrossers. As with those more sporting applications, aluminum opened a multitude of options for Aoki's engineers, letting them make the new chassis light precisely where it needed to be and saving weight elsewhere when possible.
"The new Gold Wing's higher dynamic performance levels demand more of key structures such as the frame and swingarm," Aoki says. "Those demands and limited space made the internal frame shapes very complex." That complexity paid off with staggering gains in stiffness. The aluminum Gold Wing frame gains 119 percent more lateral rigidity over its steel predecessor, along with 77 percent more torsional rigidity.
Aluminum also delivers some amazing manufacturing advantages. "The high degree of design freedom of Honda's aluminum frame technology allowed us to build multiple functions into a single component," says Aoki. Consequently, the new dual-spar alloy frame lighter uses only 31 separate components, compared to 130 individual pieces that made up the GL1500's steel frame.
Made up of multi-box-section extruded main spars, a massive gravity-die-cast steering head and gravity-die-cast swingarm pivots and rear suspension cross-members, the aluminum frame is as light as it is strong, undercutting the previous steel frame by 25 pounds. More weight savings came from the use of a single-side Pro Arm rear swingarm, which also makes changing the rear tire much simpler than with the previous Gold Wing.
In January of 1998, Aoki and his Gold Wing team settled upon the essential chassis factors. "At that time we fixed the dimensions such as steering geometry and swingarm length that would define the handling we wanted," Aoki says. Rake was set at 29.25 degrees, compared to 30 degrees for the GL1500. Trail is 109mm, 2mm less than the GL1500. The new single-side swingarm is shorter than the GL1500's steel unit, and the swingarm pivot moved rearward. "The object," says Aoki, "was to make steering quicker, with more direct feedback for the rider."
BRAKES AND SUSPENSION
The Gold Wing would demand more of its brakes and suspension components than any Gold Wing had in the past, inspiring some intriguing applications of leading-edge Honda technology, as well as some totally new ideas. Building athletic handling manners and supreme comfort into a 792-pound motorcycle required carefully integrated braking and suspension systems with unprecedented levels of sophistication.
Up front, a massive 45mm fork houses a cartridge damper in the right leg while the left leg features Honda's new anti-dive system. Honda paired the new anti-dive system and LBS for the first time in the Gold Wing, and this innovative technology enhances stability across the Gold Wing's broad operating range.
"The new anti-dive system is designed to work with Honda's LBS (Linked Braking System) and the optional anti-lock braking system, which is basically an adaptation of the systems used on the CBR1100XX and Interceptor," Aoki says. "Servo pressure from front brake torque generates the actual anti-dive effect. And since the right-side fork leg is not equipped with anti-dive, it can utilize cartridge-type valving that greatly increases suspension performance." Dual full-floating 296mm front discs and a single ventilated 316mm rear disc are squeezed by three-piston calipers.
In back, the Pro Arm single-side swingarm utilizes Honda's Pro-Link single-shock system. To help damp out road shock and torque, the Gold Wing utilizes a unique driveshaft-damping system featuring a double-pipe structure, with a rubber-bonded coating applied to the driveshaft to help absorb road shock and torque input. A smaller, lighter final gearcase helps reduce unsprung mass for even greater compliance on the road.
There are just as many bright ideas at work in the Gold Wing's rear suspension. "We developed an electric spring preload adjusting system with this version of the Pro Arm single-side swingarm," says Aoki. "A small electric motor, activated by a switch mounted on a panel above the rider's left knee, drives a hydraulic jack-type spring preload adjuster to make rear suspension adjustments easy. A two-position memory function was added for even easier operation."
Tire performance was enhanced as well through all-new radial tire designs. "We specified new tires for the Gold Wing that will maintain the necessary long-wearing characteristics, but a new radial design will improve dynamic handling performance," Aoki says. "The larger engine displacement and higher torque required more grip, so the rear tire is a 60 percent aspect ratio, and width has changed from 160mm to 180mm to create a larger contact patch. Front tire size is unchanged, but the new bike's lighter weight and wider front rim will greatly increase handling performance."
Just as one look at the physique of a world-class athlete communicates something of their abilities, the Gold Wing's styling had to exemplify its more athletic character. At the same time, it needed to look like a Gold Wing. According to American Honda's Gary Christopher, the idea was to create a more engaging, mechanical look. Less bodywork would highlight more of the bike's heart and soul.
"The riders we spoke to who were interested in a high-performance motorcycle with the amenities traditionally associated with the Gold Wing wanted to see more of what made the machine tick," Christopher says. "If the bike was lighter, it should look lighter. As a bonus, that elemental look also offers more opportunities for owners to personalize their machines with different accessories."
The optimal expression of that ideal took inspiration and influence from many sources. Function was as important to Aoki's team as form. For example, those side-mounted radiators are more than just racy looking. They do a better job of routing engine heat away from the rider than a conventionally mounted unit. Turn signals integrated into the mirrors are more conspicuous to other motorists, more aerodynamic and better looking. The list goes on.
Moving from the concept stage, upward of 100 sketches representing proposed designs had been generated. By October 1997, those sketches had evolved into one finalist. Honda R&D Asaka and Honda Research America both set about creating a 1/8th-scale clay model, an unprecedented step that underscores the project's significance. In February 1998, an internal competition selected the best aspects of the Japanese and American designs, and a final full-scale model was created.
No single facet of any motorcycle design exists in a vacuum. All aspects of the Gold Wing are interrelated, sometimes in surprising ways. Honda is well aware of the potential synergy in those relationships, and used it to advantage wherever possible. "The riding position on Gold Wing is 50mm closer to the fairing and windshield compared with GL1500, which gives the rider more direct steering feel," Aoki says.
"By moving the rider into the pocket of neutral air behind the fairing, we were able to design a smaller fairing with less frontal area and 10 percent less aerodynamic drag. Moving the rider forward also creates an additional 2 inches of seating room for Gold Wing passengers." None of that would have been possible without the extra foot and legroom afforded by the engine's parallel valve arrangement.
As you would expect of the Gold Wing, the list of luxury features is too long to list here. Just a few of the highlights include an all-new electronic reverse system that operates with push-button handlebar controls; a new cruise-control system that responds 40 percent more rapidly than the previous GL system; all-new luggage that offers a remarkable 147 liters of storage, and features a remote control key-lock system; a state-of-the-art audio system with an optional six-CD changer; new, programmable instrumentation; and a larger, 6.6-gallon long-range fuel tank. Additionally, one of the color options for the Gold Wing is Illusion Red with Chromaflair®* brand light interference pigment, a finish that alters hue as light angle and conditions change-another first for a production motorcycle.
PUTTING IT ALL TOGETHER
Changing the course of a cultural icon such as the Gold Wing is a potentially risky business. Nevertheless, with one of the largest design teams in its history, Honda has accomplished exactly that with the Gold Wing. After pouring more than seven years of heart and soul into one of the most challenging motorcycle projects in Honda's history, Aoki and his team redefined the motorcycle that has defined long-distance luxury riding for more than a quarter-century. The Gold Wing possesses the soul of a sport bike and the comfort and amenities that have always been synonymous with the legendary Gold Wing.
* The ChromaFlair® trademark is a federally registered trademark owned by FLEX Products Inc., and is used by permission.