Honda CBX 1000 – Six Cylinder, 24 Valve 70s Super Sport

Producing a follow up to the ground breaking CB750 was always going to be an impossible task. However Honda set out to achieve it with the six cylinder CBX 1000, carrying on their tradition of ignoring the odds.

How? By simply following the same formula that had worked before; more cylinders, more valves and more power. The result of this was the world’s first 6 cylinder, 24 valve, double overhead cam motorcycle, the Honda CBX 1000 super sport.

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History of the Honda CBX 1000

Six cylinders for a motorcycle wasn’t an original idea for Honda, having previously produced the RC166 which Mike Hailwood rode to victory at the 250 cc World Championship in both 1966 and 1967. Great racers generally spawn good road bikes and in 1976, a project team, led by Shochiro Irimajiri, was assembled to develop two motorcycle engines. One would have four and the other would be a 6 cylinder and both would use four valves per cylinder, in line with their racing engines. 

After laying down the groundwork and producing the engines, the four cylinder version was passed on to another development team within Honda, who went on to produce the CB900. The 6 cylinder, named Project 422, continued under the leadership of Irimajiri and in November 1977, was launched at the Suzuka track as the Honda CBX 1000 Z.

The now iconic 1047 cc, inline six cylinder engine featured a double overhead cam (DOHC) unit with four valves per cylinder, generating 105 bhp. Being suspended from the frame meant it acted as a stressed member (an active structural element of the chassis used to transmit forces). 

Mounted to this powerhouse was a 5-speed gearbox which sent power to the rear wheel via chain drive. The 23 litre fuel tank could only achieve around 150 miles, which is a miniscule range compared to the more fuel efficient motorcycles of today. It also featured Honda’s “Comstar” wheels finished in silver.

The final production versions of the Honda CBX 1000 super sport were first displayed in the UK showrooms in March 1978 and in June that same year, were used at the Isle of Man TT by the travelling marshals.

After months of teasing the public, the Honda CBX 1000 was finally released to the public for purchase in July with a price tag of £2,750.00 (£13,880.11 in 2021). Unfortunately for Honda, due to the complexity of the CBX 1000, only one insurance company was prepared to cover riders. This resulted in very slow sales and by the end of 1979, dealers were discounting them to £1,750.00 (£8,832.80) just to get them out of the showrooms.

The American market didn’t get their hands on the Honda’s super sport until 1980 when it released the CBX 1000 A. By this time several improvements over its predecessor had been made mostly around the handling of the bike. However there was also a reduction in horsepower: due to tighter emission laws, Honda had to configure the camshafts and silencers resulting in the Honda CBX 1000 putting out 98 bhp, a loss of 5 bhp over the European model. 

Other changes included air pressure valves at the top of the forks to vary stiffness and preload and the final drive chain was also changed to a 530 size which was said to reduce noise. The Honda CBX A was also fitted with reverse black comstar wheels as opposed to the silver standard comstars of its predecessor. 

Total production numbers of the Honda CBX 1000 by this time were low, with 38,079 built in Japan and only 3,150 built in America at their Ohio factory.

By 1981, Honda realised that the CBX 1000 super sport was not selling as well as they had hoped and so took the bike in a new direction. With the new CBX 1000 B they reconfigured the bike as a sports tourer, with full fairing, engine protection bars and optional luggage. Overall resulting in a 24 kg weight gain. 

To help with the extra weight and make the bike more comfortable over longer distances, Honda  changed the rear suspension from dual to mono shock, and introduced the progressive linkage system, the Pro-Link. They attached the mono shock at the bottom to a moveable linkage system rather than directly to the swingarm, giving the shock absorber and rear wheel more independent movement. Honda also upgraded the brakes with ventilated discs and twin piston calipers to help stop the now heavier machine.

1982 was the last production year for the CBX. The CBX 1000 C model was introduced and the only changes Honda had made to distinguish it from B model were to include a pillion grab rail, and a colour change to Pearl White. Honda had officially shifted its focus away from sportsbikes and were now focusing on the touring rider and the need to travel greater distances comfortably.

Honda CBX 1000 Specification

  • Engine: 1,047cc DOHC air cooled inline six cylinder 
  • Claimed power: 105hp @ 9,000rpm / 77kW
  • Top speed: 140 mph / 225 km/h
  • Fuel tank: 23 L / 6.08 US Gal
  • Seat height: 810 mm / 32 inches
  • Weight: 272 kg / 600 lb

Honda CBX 1000 Performance

Following a four-day review of the CBX 1000 at Orange County Raceway, Willow Springs Raceway, and the Webco dynamometer in February 1978 Cycle Magazine published the following “The objective – to build the fastest production motorcycle for sale anywhere in the world – has been met.” Going on to compare the CBX 1000 super sport to the CB900F they wrote “The Honda CBX 1000 feels better and goes better, and the difference is greater than the difference in price, so the costlier bike is actually the better bargain. The CBX 6 cylinder engine is as responsive as a racer, the nicest motorcycle to ever reach the street.”

On test the Honda CBX 1000 achieved a 1/4 mile time of 11.64 seconds at 117.95 mph (189.82 km/h), the 1978 bike was also the first to go over 130 mph (210 km/h). The 1979 CBX 1000 could cover a quarter mile in 11.36 seconds and matched the terminal speed of the ‘78 model at 117.95 mph (189.82 km/h)

Honda CBX 1000 at the track
a Honda CBX 1000 dressed for the track – Image by Martin Bacher

Buying a Honda CBX 1000

Honda did not sell many of the CBX 1000. It was a motorcycle that, despite the huge popularity, your everyday average rider couldn’t afford, couldn’t get insurance for, or were intimidated by, they instead settled for the CB900F.

There are a handful still available for sale in the online world with prices varying between the models. The earlier 1978 Z super sport motorcycles are now a collectors item with price tags starting around £18,000, that’s £5,000 more than the original asking price in today’s money and for a second hand machine at that.

On these earlier motorcycles the plastic swinging arm bushes were known to wear out quickly so look for any lateral movement in the back wheel.

The A version from 1979-1980 is more readily available as the Honda CBX 1000 was launched to the American market and also produced there for the first time. A low mileage CBX 1000 can be found for £12,000 but you may have to travel to Europe for it. 

On both the Z and A models, it is worth checking to see if the exhausts are correctly sealed to the engine head and if the carburetors are properly adjusted. If not this can result in burnt out exhaust values requiring a full system replacement.

Both the sports tourer 1981 B and 1982 C do not fetch as much as the original super sport models. Modest examples are fetching around £10,000.

Restoring a Honda CBX 1000

If you’re looking to restore any variant of the Honda CBX 1000 expect to pay in order to get it up to standard. Parts are available for all models. However you will pay a premium for them. For example, a new fuel tank for the 1979 A CBX will set you back around £900.

There is the choice to opt for second hand parts which would cost half the price, however tracking down specific items will prove difficult. Hopefully Honda will add the CBX 1000 to its refresh program in the coming years to help solve this.

Is Honda’s 6 Cylinder a Future Classic?

The original super sport variants, the Z and A models, have sustained a high collectors value over the past 4-5 years, fetching between £16,000 – £21,000 for exquisitely restored examples. A good sum, however purchasing one for restoration is extremely rare due to the lack of availability and so the value of these models has flattened recently.

The touring models, B and C, have just started creeping into a classic status, as a result the price has spiked dramatically over the past three years. Three years ago a fully restored Honda CBX would sell for between £7,000 – £9,000, today they are being valued between £14,000 – £18,000. If you are looking for an investment, either of the 1981 or 1982 models would be the ones to hunt down.

Verdict

Those who have read my previous articles will know I’m a huge fan of Honda and how they like to innovate and push technology forwards. The six cylinder CBX 1000 was not as bold as its predecessor, the CB750, however it was a worthy successor even if its sales numbers were low.

It was also the motorcycle that forced Honda to change its thinking about target markets. Rather than focusing solely on having the best super sport, it showed them there was value in directing their attention more to their touring customers and tailoring a bike to suit the long distance rider. This is very much in line with my way of thinking.

I would certainly want to own a Honda CBX 1000 one day, standing side-by-side with a CB750 with its 6 cylinders engine sticking itself forward to be noticed. The biggest problem I would face is choosing between the original super sport or the sport tourer…

Honda CBX 1000 - Six Cylinder, 24 Valve 70s Super Sport

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