Four stroke, longitudinal 800 V-twin
cylinder, camshaft nestles at the base of the V between the cylinders. ,OHV, 4 valves per cylinder operated by pushrods
Capacity
497 cc / 30.3 cu-in
Bore x Stroke
78 x 52 mm
Compression Ratio
10.0:1
Induction
2x 34mm Keihin carburetors
Ignition
CDI
Starting
Electric
Max Power
50 hp / 37.2 kW @ 9000 rpm
Max Torque
46 Nm / 33.9 lb-ft @ 7000 rpm
Clutch
Wet, multi-plate, 5-speed
Transmission
5 Speed
Final Drive
Shaft
Front Suspension
33mm Showa telehydraulic fork
Front Wheel Travel
132 mm / 5.1 in
Rear Suspension
Swinging arm fork with adjustable shocks absorbers
When introduced, the Honda CX500 was a novelty. It was the first mass produced
motorcycle to feature tubeless wheels along with the CBX, it had a very peculiar
design that didn’t appeal to journalists, it was unusually large and heavy for a
500 – and it still managed to work very well, thank you very much. It wasn’t
perfect, but it was a better compromise for many than anything else offered for
the 1978 model year in its class.
The engine on which the CX 500 was based was originally developed for a small
car. Strangely, the first model run produced noticeably more power than the
later ones. Top speed prone has been recorded up to 187 kph / 116 mphand 0-100
kph / 0-62 mphcould be over in just 5.4 seconds along with a standing start
quarter-mile in 13.4 seconds. These early engines produced a true 50 hp at the
crank, as Honda promised in their pamphlets. For whatever reason, power soon
dropped into the 42-43 hp brackets, although Honda retained the original
specifications. This resulted in typical top speed figures of just over 170 kph/
105 mph and accordingly slower acceleration.
The CX engine was highly unconventional, and to this day its design has never
been replicated. To keep the engine narrow, it was made into an 80-degree V.
This resulted in less than perfect primary balance, which require 90 degrees,
but through good balancing there was very little penalty paid in the form of
vibrations. In fact, the CX ran smoother than a Moto Guzziwith its theoretically
perfect 90-degree splay between the cylinders.
Liquid cooling was still considered somewhat exotic for motorcycles back in the
end of 1977, when the CX was introduced to the press, but helped to controlboth
noise emission as well as engine temperature. The cooling fan was directly
driven from the camshaft and often led to overcooling. With the GL500 in 1981,
the engine was revised slightly and received an automatic cam chain adjuster,
TCI ignition (previously CDI) and an electric cooling fan.
Despite the novel design and effective cooling system, the CX wasn’t entirely
trouble free. The cam chain tensioner in particular gave lots of trouble as it
was too weak and broke. Unlike most engines, this didn’t cause any immediate and
complete engine destruction, although the noise from the flapping cam chain was
alarming enough. It took Honda several attempts and a couple of years to fully
sort the cam chain tensioner malady.
Overall, the Honda was very easy to maintain. Valve access couldn’t be easier,
and adjustment took only a few minutes. The clutch was in front of the engine
beside the oil filter cartridge, and the gearbox could be removed as a cassette.
However, in order to gain access to the gearbox, cam chain and ignition, the
engine had to be removed from the frame. Although this may sound bad, it was a
rather simple process what with the engine being part of the frame. Hence there
were no down-tubes to deal with and the frame could more or less be lifted off
the engine in a couple of hours, leaving the engine free. Not quite as simple as
that of a Guzzi small block, but easier than that of a BMW airhead.
Honda decided to splay the cylinder heads 22 degrees in order to move the carbs
out of the way from the rider’s feet, and hence had to move away from their
normal OHC design and over to OHV with pushrods. Although considered obsolete
and agricultural by many, the little Honda could still rev to 11,000 rpm before
valve float set in. Honda even claimed they could make their engine rev reliably
to 12,500 rpm. For the production model, redline was set to 9700 rpm, but the
owner’s manual also stated that the engine could be revved to 10500 for short
bursts during hard acceleration.
Honda promoted the CX500 as both a sports- and a touringbike, although it was
much more of the latter than the former. The suspension was overly soft in order
to give a compliant ride; too soft for hard cornering as well as for touring
with a heavy load. The aftermarket soon offered air kits for the fork and heavy
duty shock absorbers for the rear. Still, stiffening the front springing
couldn’t help the spindly 33 mm stanchions in their quest to guide the bike
accurately. With the later GL series, the stanchion diameter grew to 35 mm,
whereas the Turbo received 37 mm jobbies. Still, despite its many small issues,
the bike worked splendidly for the sort of riding most riders actually do.
Shaft final drive was a great convenience for the touring rider or the commuter
riding in inclement weather, but again not ideal for the sporting rider with
high demands for precise handling. Although far from as distinct as that of the
period BMWs, the little Honda still showed very noticeable shaft drive
reactions. Under acceleration the swing arm would be pushed down, raising the
rear end in the process and stiffening the suspension. Trailing throttle would
have the opposite effect, robbing the bike of precious cornering clearance as
well as upsetting the suspension. Again, this mattered little for the majority.
In Europe, the CX family all had twin front discs, contrary to USA where most
only had a single front disc brake. Apparently, the addition of a second disc
did wonders for the bike’s stopping ability, as there were few complaints about
braking power in Europe, contrary to USA where the single disc was generally
found lacking.The later EuroSport versionin addition featured a rear disc brake
in place of the previous drum item.
Over the years, the CX500 engine propelled seven different variants; CX500A/B,
CX500C, CX500D, CX500E, CX500TC, GL500 and GL500I. The A/B, D and E were what
today is considered standards or nakeds, whereas the C and GL were more cruiser
oriented. The TC had a turbo and a full sports-touring fairing, while the
GL500I, for Interstate, featured full luggage and the same fairing fond on the
Gold Wing 1100. For 1983, the CX grew to 673 cc and was named CX650.
Unfortunately, Honda decided to drop the whole CX line at the end of 1983 for
most markets.Although production remained for another two years, sales had
dropped off markedly. With nearly 400,000 CX’s sold over the years, though, it
was one of Honda’s biggest successes after the CB350 twin had totally dominated
the market a decade earlier. - Eirik Skjaveland
Any corrections or more information on these motorcycles will be kindly appreciated.