The Honda CBX 1000 story, video inside


Posted on Mar 5, 2009 10:30:53 PM by Richard
in CBX, custom
The CBX Story
The Honda CBX inline 6 cylinder 1047 cc was produced over the period 1978 - 1982.
This is the story about the bike, how it came about and what legacy it enjoys in the motor cycle design history.

A short history of the CBX
In 1978, Honda's development team headed by Soichiro Honda, finished work on the 1047 cc, 24 valve, six cylinder "CBX." It was the final of three designs of the CBX engine. The three options initially considered for design were the four cylinder 1000cc and 1200cc engines, and the six cylinder 1047cc.

The 6 cylinder 1047 cc design eventually won the day, but not without numerous design complications. Clearly the initial headache was that of managing a workable design using an engine 585 mm wide. Narrowing the width of the crank case, widening the tank area and tilting the engine forward by 30 degrees were some of the design aspects that were use to make it work.



Design
An interesting challenge was that of the sound it produced! The original exhaust produced a sound which was deemed too loud and risky for the marketing of the bike and so the exhaust was redesigned.

Honda wasn't new to the 6 cylinder engine though, having produced the previously successfully 247 cc, RC166, which Mike Hailwood won the 250 cc World Championship with in 1966 and 1967. Mike Hailwood also set a new TT record riding the same modified bike in the Isle of Man later on.

Production started
Production began in late 1978, and the new "'79" Honda was soon on showroom floors pulling the crowds in around the globe. When Honda unveiled the CBX, the motorcycling world was unanimous in its acclaim.

Every now and then, a mechanical device makes an indelible mark on history, for the motorcycling world 1979 was a watershed year. CBX, the worlds first 6 cylinder, 24 valve Double Over Head Cam 1047 cc was launched. Yet the charisma lay beyond the groundbreaking specifications, somewhere beyond the motorcycle in it's promising repose on the road, awaiting the rider..

A legend to this day
The double overhead cam, air cooled, six cylinder engine was a short stroke unit (to enable safe high revving to 10,000 rpm) with a bore and stroke of 64.5 mm x 53.4 mm giving 1047 cc, a compression ratio of 9.3:1, topped off with an awesome 24 valve head. With four valves per cylinder, the spark plug was mounted centrally in the combustion chamber. The crankshaft was a one piece forged component driving a 350 watt generator. Six 28 mm carburetors with accelerator pumps fueled the engine which produced 105 bhp at 9000 rpm (measured at the crank). Transmission was via multi-plate wet clutch, five speed gearbox and 630 size chain final drive.

Engine width was kept to a minimum by mounting the CDI and alternator behind the crankshaft. The motor sat in a light chrome molybdenum diamond type frame with eight mounting points; four at the cylinder head and four at the gearbox. Suspension came courtesy of oil damped 35 mm telescopic forks up front and 'FVQ' twin shock absorbers and swinging arm at the rear. By modern standards, the Comstar wheels were shod with skinny sized tyres - Dunlop Gold Seal 4.25 x 18 in rear and 3.50 x 19 in front.

Braking was handled by twin 10.9in discs up front and a single 11.6in disc at the rear. The whole package weighed in at 545 lbs dry. Class-leading 11.55-second quarter-mile times came easily to the CBX. It was the quickest, most powerful production motorcycle the world had ever seen, and an unbelievable technological achievement.

 1980 - Model "A"
Who? they asked, was the CBX rider? - A man experienced in the foibles and eccentricities of lesser motorcycles, a man looking for the exceptional bike - who has probably ridden several good ones without being wholly satisfied, until now..

The 'A' model CBX was released in the U.S. in 1980. It featured incremental improvements in a number of areas, mostly handling-related, but lost some horsepower. The 1979 'A' model was identical to the 'Z' except that it was red. Both 'Z' and 'A' models proved reliable machines, the only reported problem being that the left hand carburetor could flood. This was rectified on the later 'B' model which was fitted with a vacuum fuel tap. In 1980 the CBX (in black livery) hit American shores and in so doing lost some of its fire.

Bikes tested in the States were producing 98 bhp at 9000 rpm. Tighter emission controls had meant redesigned silencers which stifled some power but internally the main change was the use of different camshafts. However, this slight loss of power seems to have been a little academic and midrange power was reported to be as good as ever. Handling was improved over early models by changing the plastic swinging arm bushes for a double end-thrust ball and needle roller assembly mounted on a larger swinging arm pivot and stiffer swinging arm.

The 35 mm fork legs were retained but now featured air pressure valves at the top to vary stiffness and preload. The sliders also ran on new style bushes of a Teflon-lead-bronze alloy (as used on Honda's moto cross machines) to improve suspension movement. The final drive chain was also changed to a 530 size which was said to make the drive less noisy.

1981 - Pro Link
Honda reconfigured the CBX for 1981 as a sports touring bike, with fairing and saddlebags. The rear suspension also changed from dual to mono shock, and saw the introduction of the progressive linkage system - hence the name Pro-Link. The mono shock was attached at the bottom to moveable linkage instead of directly to the swingarm, changing it from a fixed to a variable ratio of shock absorber / rear wheel movement.

In Europe the CBX1000 went through the only major specification change of its four year life span with the introduction of the CBX1000B (from engine number SC03E2301512 and frame number SC06-230065). From pure sports, it now devolved into a sports/tourer. Cosmetically the CBX1000B gained a full fairing with storage pockets, engine protection bars and a 54lb weight gain. The brakes were upgraded to help stop the extra bulk, now featuring ventilated discs with twin piston calipers.

The suspension was changed dramatically with the front forks being increased to 39 mm, with the rear suspension now sporting Honda's mono shock 'Pro-link' system and an aluminum swinging arm. This had the knock-on effect of increasing the wheelbase from 58 in to 60 in. Internally the motor was in the same state of de-tune as the American models, with output being a claimed 100 bhp at 9000 rpm. Other changes included adjustable handlebars, an adjuster for headlight level, together with the option of hard panniers. The bike was finished in a dark silver grey with reversed black Comstar wheels.

1982 - Pro Link
1982 was the final year for the CBX - The 'C' model was introduced and differed from the 'B' in only two respects - it now featured a pillion grab rail, and the colour change to "Pearl White". Honda was now targeting the touring riders needs, to travel greater distances comfortably. The race inspired Pro-Link suspension was perfected to provide progressive spring and damping rates.

Yet at the heart of this magnificent bike, was the awe inspiring 6 cylinder engine that provided the power to satisfy any performance enthusiast.

To end this post I have found a video with a CBX in it that sounds awesome.
Source: cbx6.co.uk, youtube
 
Advertisement