By Nick Hoppner
All Gold Wings are not created equal. Sorry to burst anybodys bubble, but its true. In fact, no two motorcycles behave exactly alike. Add to that the differences inherent in different riders skills and you can understand why one persons Gold Wing doesnt come to a halt in as short a distance as the next guys (or gals).
lthough todays non-ABS GL1800s supposedly weigh 792 pounds when they roll off the assembly line at Marysville, Ohio, and GL1800s with optional anti-lock braking systems (ABS) are said to weigh seven pounds more, we all know that a Wings weight doesnt stay stock for long. Accessories, modifications and decoration, not to mention luggage, fluids and passenger weight quickly lard on the avoirdupois. Likewise, brake rotors and brake pads quickly become individualistic the more theyre used or changed, fork sliders and shocks dont all behave the same based on the chuckholes theyve encountered, and different tires have varying amounts of traction for a wide variety of reasons.
As a rule, motorcycles with long wheelbases have an advantage over shorter sport bikes and scooters when it comes to braking. Lifting the rear wheel from the pavement under hard braking (the classic stoppie) is fairly common for sport bikes and less so for heavy cruisers and tourers. Typically, the longer the bikes wheelbase is, the further the bikes center of gravity is aft of the front tires contact patch. Ergo, a big bike is less likely to lose all its friction between the rear tire and the road surface under strong braking. (When was the last time you saw somebody nose-loop a GL1500?) Indeed, in many cases of over-enthusiastic braking, the front tire of a king-sized bike slides first, losing all its available friction and washing out the front end. Riders with the experience or presence of mind to know whats happening to them will keep the binders on and ride out a low-side slidethe lesser of two evils. Riders who panic and release the brakesallowing the natural centrifugal forces of the bikes spinning wheels to attempt to upright the bike in the opposite directionmay be thrown free in a classic high-side. Ouch! Neither of these scenarios is a fun way to end a days ride.
The Ideal Scenario
In a perfect world, all motorcyclists would apply their bikes front and rear brakes properly. That is, theyd apply steadily increasing pressure to both front and rear brakes up to the point of reduced traction, then slightly modulate the pressure to either the front or rear wheel (whichever is closest to locking up) to avoid a skid. Highly experienced ridersparticularly those with lots of off-road experience on loose surfacesdevelop a feel for this kind of braking and do it without a lot of sophisticated technological help.
But accident statistics indicate to motorcycle manufacturers that too many street riders under stress apply too much rear brake and insufficient front brake in extreme braking situations with unfortunate results. So the manufacturers developed sophisticated braking systems to compensate for riders errors and, hopefully, to reduce the severity and frequency of motorcycle crashes.
A Gold Wing Braking System Primer
In its earliest incarnations, the Gold Wings braking system was a fairly straightforward setup typical of other bikes of the 1970s and early 1980s. The GL1000 and GL1100s, though equipped with dual disk brakes up front and a single disc brake in the rear, maintained separate hydraulics to each. Thats why riders of these classic bikes can more dramatically skid the rear wheel of their early generation Wings when taking an Experienced Rider Course.
TRAC® & Unified Braking
In 1983, Honda updated its GL1100 series Gold Wings by adding their new four-way adjustable Torque Reactive Anti-Dive Control (TRAC®) system to the front forks. This was to alleviate some of the front fork compression as the bikes center of gravity shifted to the front wheel under hard braking.
Coupled with this change, Honda also made unified braking a standard feature on all Gold Wings from 1983 forward. With the Unified Braking System on the 1983 Gold Wings, your foot pedal applied direct pressure to the right front disc and activated the rear disc through a pressure control valve. The handlebar lever controlled the left front disc only. On the 1984-2000 Gold Wings your foot pedal applied direct pressure to the left front disc and activated the rear disc through a pressure control valve. The purpose of Unified Braking was to prevent premature rear-wheel lock-up due to inexpert, lead-footed braking, yet allowing you more control of a constant ratio of front/rear braking until the rear control valve took over. This braking system was used throughout the GL1100 series, the GL1200 series and the GL1500 series of Gold Wings.
With the introduction of the 2001 GL1800, Honda incorporated a cartridge damper into the right front fork and a new anti-dive system into the left fork of the front suspension. The new anti-dive system uses brake fluid pressure generated in a secondary master cylinder mounted on the left fork leg. The anti-dive is activated by input from either the front brake lever or the rear brake pedal.
Working in conjunction with this new anti-dive system is one of Hondas two new braking systems on the Gold Wing GL1800: a linked brake system (LBS) or a linked-brake system with optional anti-lock brake system (ABS).
Linked Braking System (LBS)
The linked-brake system is designed to engage both front and rear brakes when either the brake lever or the brake pedal is used. The system features a second master cylinder and a three-stage proportional control valve to couple the three-piston calipers of the dual-front and single-rear brake discs. By squeezing the front brake lever, you activate the outer two pistons of the front right-side caliper and the center piston of the front left-side caliper. Acting through the secondary master cylinder and an inline proportioning valve, the outer two pistons of the rear caliper are also activated. When you depress the rear brake pedal, you operate the center piston of the rear brake caliper, the center piston of the front right-side brake caliper and the outer two pistons of the front left-side caliper. A delay valve sensitive to the pressure you apply to your brake pedal smoothes your front brake engagement. The purpose of linked braking is to reduce even further the possibility of applying excessive braking to either of your motorcycles wheels, further reducing the possibility of skid.
Anti-Lock Braking System (ABS)
GL1800A models incorporate the complete LBS system described above with an electric motor-driven modulator that provides rapid and precise braking-pressure adjustments, resulting in smooth ABS operation. The system has an integrated ECU, self-diagnostics by way of an interactive ECU test function, and automatic protection against system failure. Data from wheel speed sensors is constantly compared by the systems computer. Should one wheels speed suddenly decrease drastically in comparison with the other wheel, the computer figures that wheel is now locked up. Immediately, the computer pulsates the brakes until equilibrium is restored. The purpose of anti-lock braking is to sense electronically when a wheel is about to skid, then to automatically release and reapply braking forces many times per second to prevent wheel lock-up. This system is particularly effective on wet, slippery or loose surfaces. Should your ABS system fail, you still have all the components of LBS working for you. (Do you know what it means if the little red ABS light on your GL1800As dashboard blinks continuously or stays illuminated after startup?)
Rider Opinions Differ As To Whats Best
Old-timers and purists tend to hold ABS systems in disfavor, saying (rightly) that any system that releases your brakes tends to lengthen the distance of a panic stop. Advocates of ABS counter that if your Wing is now in full-slide mode, braking distance ratio arguments are moot. Its true that riders dont execute as much personalized control if control has been taken over by on on-board computer or a linked system of hoses and valves. But for many riders, the extra margin these systems yields is like insurance they hope never to need.
Every System Has Its Limits
As motorcycle educator and author David Hough says in More Proficient Motorcycling, Whether you have ABS, integrated, linked or power brakes, there is a limit to what the braking system can do for you. For instance, the brake system cant save you from a skid caused by snapping off the throttle in a curve. Quick stops are still dependent upon rider skill and upon brake system maintenance.
No matter how sophisticated your braking system, theres a vital component to your braking system thats often overlookedthe skills and judgment mounted between the riders ears. Even if your bikes brakes are in tip-top condition, they cannot stop a side-sliding elephant on a Teflon-coated highway. Nine-tenths of accident survival is based on accident avoidance. Rider education and practiced braking skills are invaluable tools to diminish your need to find out how effective your brakes are when the chips are down.