Much thought went into the design of Honda's 500-class full-dress tourer. The
existing CX500 V-twin engine would obviously be the ideal choice as power plant,
but what about the chassis? One faction of Honda development guys thought the
best approach was to take the standard CX—engine, chassis and all and simply
bolt on a fairing and some saddlebags. Another group wanted to see the pushrod
V-twin powering an all-new chassis one designed from the ground up for touring
use with a fairing and bags, something with more advanced engineering and clean,
Luckily for the middleweight touring rider, Honda finally settled on the
latter approach. What they came up with has been dubbed the GL500I Silver Wing
Interstate, essentially a smaller version of the GL1100 Interstate introduced
last year. Since both machines are fitted with the same injection-molded plastic
fairing, the similarities in the styling of the two bikes are striking. No other
pieces interchange, however; the GL500 is built entirely as a 500-class machine.
The GL500 is available two ways: fully dressed and ready for open-road work,
or stripped-down without the fairing and saddlebags (the version we tested in
our June middleweight comparison). The only mechanical difference between the
two machines is in the front brake. The Interstate has dual discs and Honda's
twin-piston calipers, while the stripped-down GL has one larger diameter disc
and a single twin-piston caliper. In virtually all other respects, the two GLs
The four-valve twin that powers the Interstate is pretty much the same unit
that has seen action in the CX500 for the past few years. The only differences
are a change from magneto CDI to transistorized ignition and longer intake
manifolds to provide a more inboard carburetor location. The little
plain-bearing V-twin is a willing revver redline is 9700 rpm. Low (high
numerically) gearing has the GL spinning a brisk 5395 rpm at 60 mph in top gear,
but the 80-degree V engine layout keeps vibration comfortably low. Engine and
drive-line maintenance are simple on the GL, since the water-cooled engine is
equipped with easy-to-service, threaded valve adjusters and low-maintenance
shaft final drive. There's enough horsepower on hand to push the Interstate
through the quarter-mile in 14.94 seconds at 86.04 mph—or about a second slower
than the unfaired GL. The Interstate's roll-on terminal speed after 200 yards
from 50 mph in top gear is 67.6 mph—only two mph slower than the GL's. The
Interstate isn't particularly big on mid-range power, but it is carbureted
cleanly and builds its power predictably as the revs rise. The GL can easily
work up enough speed to exceed the national limit when fully loaded, but steep
hills and high altitudes often require a downshift or two and plenty of revving.
High engine speeds send a healthy buzz through the pegs and drop the fuel
mileage considerably. Our test bike occasionally turned in tankfuls that ran in
the low 30s when pushing strong headwinds and climbing steep hills.
Since it employs the same gearbox and clutch as has been used in the CX500
since its introduction, the GL can be a balky shifter. Upshifts must be executed
deliberately to prevent occasional missed shifts. During drag-strip-type speed
shifts the GL's clutch slips. Luckily, this type of shifting abuse isn't
standard fare for touring riders. The clutch has its good points during normal
use. The lever pull is light and the engagement smooth and predictable.
The four-valve engine is an excellent basis for a middleweight dresser, but
just as important is its chassis. It is entirely new, and incorporates a number
of features to make it a better touring platform. The GL's wheelbase is longer
than the CX500's, and the steering geometry is slower to provide more stability.
Even with these changes, the Interstate steers lightly and easily. There's also
a bit more suspension travel at each end to better handle bumps and potholes.
Suspension-wise, the GL has a lot more on the CX than just travel. Instead of
the CX's conventional dual-shock rear suspension, the GL has Honda's Pro-Link
system. A single shock is mounted vertically between the swingarm and engine,
and is connected to the swing-arm with a linkage. This linkage delivers
rising-rate suspension geometry, meaning that the farther the suspension
compresses, the more the shock's leverage deficit is reduced. This progressivity
keeps the suspension soft and responsive to small bumps, while allowing it to
become stiffer to handle big bumps. The Showa damper has fixed damping and a
straight-rate coil spring. An adjustable air spring built into the shock lets
you fine-tune the suspension action to suit load and riding conditions. The
pressure can be set anywhere between zero and 70 psi, so there's plenty of room
The Pro-Link makes the GL the smoothest-riding middleweight on the highway.
The rear suspension is very responsive to small lips and seams in the pavement.
There's little of the usual spine-pounding on those cursed freeway expansion
joints, so long hours on the super-slab seem to pass more quickly. Thanks to the
progressive geometry and air springing, the Pro-Link eats up the big bumps too.
With the air pressure adjusted to cope with the rider and cargo weight,
bottoming isn't noticeable. The only drawback to the system is the shock's
marginal rebound damping. The light damping undoubtedly contributes to the
excellent responsiveness on small bumps, but it isn't sufficient to keep things
under control when the shock rebounds after a big impact. The back end of the
Honda pogos somewhat on bumpy roads, occasionally badly enough to bounce the
rider up off the seat during fast riding. The same damping insufficiency
contributes to a chassis instability on high-speed corners. The Interstate isn't
the appropriate tool to use to hone your road-racing skills, and isn't intended
to be. However, a bit more rebound damping would improve the bike's handling
under almost all conditions, while only sacrificing a tiny portion of its
butter-smooth ride on the highway. We experienced the same damping shortage on
the standard GL, too.
The front fork nearly matches the responsiveness of the Pro-Link, but
delivers far more wheel control. The air/ spring fork's stanchion tubes can be
inflated at a common filler, so adjustments are simple. Honda's dual syntal-lic
bushings cut down on stiction to make the fork more responsive to sharp lips and
jolts. The 35mm Showa fork never bottoms noticeably, even during hard braking on
large bumps, provided the air pressure is jacked up sufficiently in advance.
Honda didn't cut corners in the braking department either. Up front, a pair
of discs are gripped by powerful, dual piston calipers. A two-fingered squeeze
on the lever will bring the front brake to the point of lock-up, and the feel is
excellent. In the rear, the single-leading-shoe drum-type brake is adequate.
Though the chassis bits are all pretty decent stuff, they're outshone by the
slick touring gear. The large fairing has an adjustable windscreen and pro vides
excellent protection. Even tall riders easily fit within the pocket of calm air
created by the fairing. The fairing-mounted mirrors vibrate somewhat and are
positioned far away from the rider, so the images are small and blurred at
certain engine speeds. Small adjustable vents built into the fairing are
intended to let fresh air in behind the fairing if desired, but they are too
small to be effective. Honda offers an optional AM/FM radio, a clock and a
voltmeter to mount in the fairing dash. Though the upper-body wind protection is
excellent, the abbreviated fairing-lowers leave your lower legs in the wind. On
hot days, this is a blessing, since hot air from the engine's radiator fills the
calm air envelope and makes the rider uncomfortably hot. Of course, on cold
rides this heat keeps the rest of your body warm while your legs are chilled.
Two compartments in the fairing provide storage space and can handle five pounds
each. The one on the left has a snap-down vinyl cover; the right one's plastic
lid locks with the ignition key.
The Interstate comes equipped with a decent, though not remarkably good, solo
saddle and storage trunk. If you wish to carry a passenger, the trunk must be
unbolted and replaced with the passenger seat included with the bike. The
lockable trunk can handle 20 pounds worth of gear, and is much larger than the
compact trunk that comes standard on the stripped-down, unfaired GL500. The
smaller trunk can be purchased separately as an accessory.
The saddlebags are nicely finished, detachable units that lock shut and in
place on the bike. They feature sturdy aluminum frames with rubber gaskets to
keep water out and internal elastic straps that make it easy to secure the
contents. Honda suggests that each bag be loaded with no more than 20 pounds
worth of cargo. The bags are deeper than those on the CBX, so they hold
considerably more. Our only complaint is with the overly complicated mounting
system that uses several latching mechanisms, including seat belt-type buckles
and locking arms. The bag-mounting mechanisms on the CBX are much simpler, and
they don't pinch your fingers. Like all the locks on the bike, the bags' locks
are operated by the ignition key.
At least for the moment, Honda's GL500 Interstate is literally in a class by
itself. No other manufacturer currently offers a ready-to-ride, full-dress
middleweight tourer, so the only alternative to the Honda is to do it yourself.
If you go that route, it's unlikely that you'll come up with anything that will
match the integration, fit and excellent finish of the Silver Wing Interstate.
Source Motorcyclist 1981