1978 Honda CX 500 - Motorcycle Specs

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