1979 Honda CBX Road Test - page 6

The bike, as a styling exercise, is lean and elemental. Otsuka is responsible for this, and admits that the bike was nettlesome. Not just because of the size of its engine, either. It is a high-performance bike, and to express high performance in styling is "most difficult." The motorcycle emphasizes its own performance function by being what it is; the styling has to evoke this, and must never lead the imagination down the garden path toward conclusions of any other kind. There were spatial and mechanical problems to solve at first, and these - like providing room for the rider's knees, and keeping the weight down-were beaten back as Otsuka and Irimajiri reached compromise after compromise. Otsuka then began to shadowbox against the flickers and ghosts which populate the stylist's world.

Styling can be many things. It can festoon the surface like decoration; it can burrow into the shapes of components and structures and tweak one's impression of their purpose; or it can-and this is the toughest of all-clear the space between the observer and the function of the object, so that nothing stands in the way of the capabilities of the device he is observing. This can be attempted by the stylist only if the superior function of a given device is its main message. Apply the philosophy to anything else - anything less - and the result is caricature at best and at worst, deceit.

In the CBX Otsuka knew he had the essence of function, and so his task became one of transmitting that message unhindered and without modification. The fuel tank shape responds only to the demand for capacity, the design of the chassis and the physique of the average rider. The side covers, truncated triangles finished in black, are essentially that: covers. Otsuka's only extravagance, if you accept that the tank striping controls that vessel's visual bulk, is the seat/tail section. An extraordinarily light (5 lbs.), fully-detachable component, the tailpiece has a little kicked-up spoiler. Otsuka admits it does nothing whatsoever except pantomime in miniature the rear deck wing of the modern Porsche which, he elaborates, does nothing on the Porsche either. Beyond this frippery the CBX does not appear to have been styled at all - which is far from the cruelest thing one could say about Otsuka or his understanding of what the bike is, and can do.

Early on, however, he ran into a problem with the instrument console. His department fashioned a contemporary arrangement that was handsome and informative. But the engineers turned it away, saying that it didn't look functional.

Back to the jets. Knowing that aircraft pilots have vast arrays of instruments to monitor and not much time to do it, and knowing that aircraft instrument designers have from the beginning recognized function as their only deity, Otsuka saw and assimilated cockpit after cockpit, altimeter after air speed gauge, intercom switch after exhaust gas analyzer. What he learned was studiously incorporated: glare-free glass, black backgrounds, bright, simple numbers and long thick needles with white tips. It looks easy. It was not.

We had not been in the company of Mr. Irimajiri for more than twenty minutes before he mentioned his two biggest problems with the CBX. Engine width of course was one; overall weight was the other, and while he subdued the first with some flashing strokes of engineering brilliance, the second became a long-term battle in the trenches. From front to back, from bottom to top, the CBX is a monument to his thoroughness in pursuit of the dreaded gram. This is what he did:

Aluminum triple clamps, top and bottom; sliders and fork pipes machined internally to reduce wall thicknesses where stresses were low; a plastic front fender; aluminum-spoke wheels (4.4 pounds lighter than steel-spoke ones) and tubeless tires (although it is not known as yet whether this is a final decision, since the tire manufacturers are not sure that the insert-plugs, which will be supplied to fix flats, will stay in place at the speeds the bike is capable of producing); drew up the engine as a wet-sump to avoid the weight of an oil tank, then designed a dual-function trochoidal oil pump which not only sends lubricant to all moving surfaces but routes it through a small, 4000-calories-per-hour oil cooler mounted below and behind the steering head; decided against turn signal buzzers and self-cancellers, and resisted the appeal of a fuel gauge; adjustable forged aluminum handlebars; forged aluminum footpegs, with their mounts recessed into the support plates for reasons having to do with cornering clearance; originally forged aluminum top motor mounts (which had to be replaced with steel ones when the alloy mounts experienced difficulty with crash tests); a chassis which weighs 29.4 pounds bare; a plastic rear fender, and a plastic seat base.

The battle of the bulge was not fought only on the CBX's ample exterior, but inside the engine as well. The camshafts, for example, are hollow, the clutch is all-aluminum and that mystic motocross substance, magnesium, has finally appeared on a standard street motorcycle. The CBX has a magnesium countershaft sprocket cover, a magnesium alternator housing and cover, a magnesium oil pick-up housing, and a magnesium shift linkage cover.

Irimajiri's struggle against weight brought him into occasional conflict with Otsuka, who would liked to have seen certain components fitted with covers; Irimajiri wasn't going for it. Tip the motor forward, yes; angle the carburetors in, yes, even though in the auricle of his heart that remembered the GP world, he hated to do it; but trade weight for style? Never. Chiseling here, trimming there, examining every component with a fanatic's eye, Irimajiri brought the CBX in under 600 pounds - 599.95, as close as our scales could measure, with the fuel tank filled to the brim and all other fluids in place. In view of the engine's muscle, however, we question his gram-pinching in three areas: the chassis, the front fork pipes (35mm in diameter) and the shock absorbers. Had he allocated a few more pounds here, there is a chance the CBX could have negotiated Willow's Turn Eight full-bore without doing the hippy-hippy shake.

Monday and Tuesday were gone; Wednesday was dyno day. Backing the plain jane refrigerator-white Ford van to the shuttered side door of the dyno room at Webco, the Honda technicians unloaded the CBX and rolled it in. It took the better part of two hours to ready it for the pump, some of which was spent waiting for the NGK representative to bring the nine-series plugs Irimajiri wanted to use. With the bike in place and all calculations done, Webco's Bob Hughes got down to business. By lunch-time we knew how much power the engine made. 85.56 at 9000 rpm, with a 52.27 pounds-feet torque peak at 6500. At 3000 rpm the engine produced 42.50 lbs/ft of torque, going up to 47.1 0 at 3500 rpm and staying over 48 from 4000 all the way to 9000. Horsepower kicked in with authority at 6500 (64.69). At 8000 rpm, fully 1000 rpm below its power peak, the CBX made six horsepower more than the Kawasaki's Zl-R's maximum. By a significant margin, the Six became the strongest stocker ever to pull against the Webco dyno.

Still, Irimajiri had reason to believe that the bike was not doing all it should. The Webco pump was installed so that the company could do meaningful development work on its line of small-displacement aftermarket engine components, and as a consequence, did not have the engine cooling capacity the CBX needed.

"On any multi," Irimajiri explained, "exhaust tuning is crucial. Waves traveling down the pipes have to behave in a certain way if optimum performance is to be obtained. How those waves travel is determined by pipe length, pipe diameter and pipe temperature. If the exhaust system is overheated some of this tuning is lost; I believe that is what is happening here."

Honda, of course, has its own power figures and torque curves. At Asaka the CBX made 103 bhp, measured at the crankshaft. Irimajiri, calculates there to be a 7 per cent power loss between the crank and the output shaft, and another 7 per cent loss between the output shaft and the rear wheel sprocket. Running through the arithmetic, it becomes apparent that under perfect circumstances the CBX should have produced just over 89 bhp on the Webco pump. Additionally, Honda measures the amount of power consumed by frictional losses in its own dynos, and adds that, rightfully enough, to a given engine's output.

Whether it makes 103, 89, or only 85.56, the CBX engine is the Lord High Pumper of all recorded time. Its general layout may seem familiar to anyone who traveled with the European GP circus a decade ago, for it really is little more than a large-displacement, streetified version of Irimajiri's 297cc Six that swept all before it in 1966-1967. But street versions of GP race engines are hardly a dime a dozen, especially if they have six cylinders and 1047cc.

Beneath a one-piece, O-ring-sealed cam cover secured by eight sealed bolts lies much of the CBX's technical other-worldliness. It has not two cams but four, driven by not one chain but two, operating not 12 valves but 24. The first close look sends the hardware junkie staggering from an overdose.

   

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