"In the hard world of commerce, achievers get imitated and the imitators get imitated. There is developing, after all, a kind of Universal Japanese Motorcycle.... conceived in sameness, executed with precision, and produced by the thousands."

And so it was, in the winter of 1976, that Cycle Magazine tattooed UJM across the Japanese arm of the motorcycle industry. But the UJM’s real genesis took place seven years earlier in the form of Honda’s CB750 four, a machine distinguished from European and British roadsters by its sophisticated, mass-produced four-cylinder engine.

Unusual and unexpected in ’69, the four-cylinder CB750 was at first perceived by motorcycling’s conservative element as a specialized machine, understood and appreciated by few. There was developing, though, a kind of Universal American Rider, decidedly hot for anything that ran the quarter in the thirteens and devoured greater distances in comfort and without shedding parts or sweating oil through every seam. Honda’s CB750 was so egalitarian, so correct in original concept and execution, that Universal American Riders snapped up more than half a million, including the 1979-1983 dual-cam CB750F, which adhered to the original UJM orthodoxy, right down to wheelbase, steering geometry and frame layout.

Then something changed. Universal American Riders flooded out of the ‘70s mainstream and into the ‘80s as sport riders, touring riders, and cruiser riders, all looking for specialized machines. The Japanese manufacturers responded with wholesale innovation—V-twins, V-fours, computerized touring bikes, repli-racer sport bikes—and the old-line UJM got lost in the shuffle. After a decade, the original SOHC CB750 gave way to a new twin-cam CB750, and after five years that CB750 passed the torch to the third-generation CB700S Nighthawk S.

Enrolled under the UJM banner, the Nighthawk S is a balance of tradition and innovation, a clean break from the kind of success through sameness that carried that SHOOK 750 through the ‘70s. Tradition dictates the 700S use an air-cooled four-cylinder engine carried transversely in a full-cradle, twin-shock frame, but modern technology has provided Honda engineers with greater latitude within the UJM concept. The Nighthawk has emerged essentially maintenance-free---hydraulically adjusted valves, shaft drive, hydraulically actuated clutch, electronic ignition—yet is smaller, lighter, faster, smoother, more sporty and more sophisticated in every way than its UJM predecessors.

Compactness is the key: the design of any motorcycle begins in the engine bay and spreads outward. Large, heavy engines beget large, heavy and often truculent chassis. The second-generation 750F, with a relatively long stroke and its alternator and ignition hung on the crankshaft ends, was tall and wide across the beam. Not only did this blunt efforts to downsize the F for lighter, more nimble handling, it also limited engine placement for optimum weight bias. Though the F handled well by the then-present UJM standards, significant improvements could come only by pitching the old mill.

The Nighthawk S engine, which uses not a single part from the old, is considerably smaller in every dimension—top to bottom, side to side, front to back—and lighter than the 750F DOHC power-plant by 17 pounds despite its hydraulic valve apparatus, overdrive sixth gear, and shaft final drive. The S is 550-small: 16 inches wide, 16.5 long, 20 inches tall. By comparison, Honda’s 700xx V-Four Sabre, while only two cylinders wide, is just an inch slimmer than the 700S. Consider this too: pinched corset-like at the waist, the V-four engine is both taller and longer than the inline S; consequently, the Sabre carries its engine higher in the cradle than the 700S, yet offers no more cornering clearance.

So how did Honda shrink the Nighthawk engine into such a compact cube? Oversquare bore and stroke dimensions are part of the answer. Exploited to the fullest, a reduction in stroke can decrease an engine’s overall height. At 49.4mm, the Nighthawk’s stroke is 12.6mm shorter than was the old F’s. This means its cylinder block can be shorter from deck to deck, and its crankshaft counterweights smaller, thus allowing the crankcase itself to shrink. A large 67mm bore (the old 750 measured 62mm) permits the design of a wider, shallower combustion chamber which can also reduce cylinder-head height. Fitting a dry-sump lubrication system---oil is contained in the frame rails—allows a shallow oil-sump. Beginning to understand?

Narrowing the engine is a more complex problem. You might think big bores, which cause correspondingly wide bore-centers, would actually widen the Nighthawk engine. Indeed, the original single-overhead-cam CB750 had undersquare cylinder dimensions in order to keep from getting too wide. The real question is where an engine is wide; it’s more important that crankcases be narrow than cylinder blocks (though the Nighthawk’s block is no wider than the old 750’s), so Honda engineers set about building a narrow engine, measured transversely, by making a short one, measured front to back. Sound like a contradiction? Not really.

Honda engineers made the drivetrain in the Nighthawk more compact than they had in the earlier (1979) twin-cam CB750F. That CB750 had four central shafts—crankshaft, jackshaft, and two transmission shafts. A Hy-Vo chain ran back from the crank to the jackshaft; on the outboard end of the jackshaft was the primary gear that engaged the gear on the clutch drum. In the Nighthawk S one flywheel cheek has the primary gear machined into it, and this gear meshes directly with its mate on the clutch. This system makes the 700 engine over two inches shorter and much narrower than the 750. Machining a straigh-cut gear into a flywheel cheek eliminates the necessity for locating a space-wasty Hy-Vo gear between flywheel sets. To keep from paying a noise penalty with straight-cut gears, the clutch gear uses a split, spring-loaded cog to cut backlash-induced noise.

An all-gear primary drive can narrow an engine dramatically—but only if the engineering department decides to remove components from the ends of the crankshaft, be they gears or alternators. Case in point: The twin-cam CB750 had its alternator hung on the left end of the crank, following a pattern established by the first single-cam CB750. In the Nighthawk S, only a small ignition unit has been left on the crank’s end; the alternator and the starter have been chucked out. Following the pattern established by their own earlier CBX, Honda resettled these components behind the cylinder bank, running on their own shaft, atop the transmission case. A small roller chain connects this auxiliary shaft to the center of the forged crankshaft; the space required for its narrow sprocket on the crankshaft is far less than the spacious accommodations demanded by the old twin cammer’s Hy-Vo 29mm chain. Result: the Nighthawk S is almost five inches narrower than the CB750F, measured at the cases along the axis of the crank.

The 700S is a triumph of dense packaging; every molecule of space exploited, every millimeter of casing wrapped like blister pack around components. And Honda’s skill in building such a compact engine is impressive: From the outset the 700S produced more peak power than the old 750. Power has a way of trashing components chiseled too small by zealous designers, yet both engines use essentially the same number of components dealt from the same deck, though shuffled differently.

Beyond compactness, the Nighthawk’s short stroke paved the way to increased peak power. The large bore provides space for a fashionably shallow combustion chamber, narrow included valve angle (38 degrees) and relatively large valves (25mm intakes, 22.5mm exhausts). This design improves combustion efficiency and airflow, while the short stroke’s lower piston speeds and light crankshaft assembly allow the 700S to rev quickly to a high-rpm ceiling. But the dynamometer reveals trade-offs. The old 750 made more torque and horsepower from the basement to 8500, building on a smooth, linear curv. The Nighthawk’s torque figures fluctuate wildly at low engine speeds—an indication of its light crankshaft and the loss of the heavy alternator’s torque smoothing flywheel effect—and it falls behind the 750F by as much as three horsepower in the lower reaches, 10 in the mid-range. Then, however, in the four-valve head begins to pay hefty dividends. In the span of 1000 rpm—from 7000 to 8000—the Nighthawk leaps almost 20 horsepower up the scale. Both engines produce peak horsepower at the 9500 rpm, the Nighthawk with 67.67, the 750 with 64.72. When the rev-limiter throws its choke-hold at 10,750 rpm, the Nighthawk holds a 3.5 horsepower advantage over the 750 at its rev-limited margin in rpm ceilings between old and new, but the old thunderdog 750 was built of pretty stern stuff, tweaked to the quick.

Considering its 50cc displacement deficit and power-robbing shaft drive (the 750 was chain driven), the Nighthawk’s advantage is significant. In terms of specific output, and power to weight (the 700S is 26 pounds lighter than the F), the 700S is yards ahead of the old 750. And compared to Yamaha’s air-cooled XJ700 Maxim, the Nighthawk is a powerhouse—eight horsepower stronger at its peak, up 3.5 pounds/feet at its 8500-rpm torque peak. The tow-valve Maxim, however, has a much smoother power curve and has a much smoother power curve and more torque and horsepower down low. Now comes the surprise: On the road, the Nighthawk’s lumpy power delivery smoothes out, the engine feeling stronger in the basement than the dyno numbers indicat. Why? Gearing. From first through fifth, the six-speed Nighthawk is geared lower than the five-speed Maxim. At the same ground speed in the same gear, the 700S is taching higher than the Maxim, crowding the meaty part of its powerband.

The slick-shifting close-ratio gearbox also backstops the engine’s willingness to rev quickly. The soft spots still exist in the powerband, but the Nighthawk simply doesn’t dwell on them.

While singing a flattering harmony with the powerband, the Nighthawk’s gearbox must work harder than the Maxim’s. Around town the S makes enough power to get you into and out of trouble, but zippy passes on the open road will have you gearing down and down again. With an extra gear in the box, however, Honda was able to fit a super-tall overdrive and retain excellent fuel economy and smooth, low-rev running at highway speeds. In fact, with its rubber mounts, the 700S engine is deceptively smooth, a quieter, more relaxed feeling unit than the Maxim, even though the S spins higher in first through fifth.

In its chassis specifications, the Nighthawk proves equally deceptive. Nothing of the conservative steering geometry—30 degrees of rake, 4.8 inches of trail, in tandem with shaft drive and ordinary twin-shock rear suspension—hints at the Nighthawk’s excellent handling capabilities. Look instead at the engine and its position relative to front and rear wheels. Being compact, the engine sits low and forward in the chassis, placing more weight on the front end and lowering the center of mass without sacrificing cornering clearance.

Comparisons between the 700S and the Maxim reveal that the Nighthawk is 2.5 inches shorter from the front axle to the crankshaft, 3.25 inches shorter from crank to the swing-arm pivot. You might expect this 5.75-inch difference to be reflected in wheelbase, but such is not the case. The Nighthawk is only 1.3 inches shorter. Where are the missing inches? From pivot to rear axle, the Nighthawk’s swing arm is 4.5 inches longer than the Maxim’s. Swing-arm length in shaft-driven motorcycles influences the degree to which the rear suspension is loaded and unloaded during acceleration and deceleration. Short swing-arm/shaft assemblies often exaggerated the up-and-down antics inherent to all conventional shaft-drive systems, but an engine of large physical dimensions needs a short shaft if the wheelbase is to be held at a reasonable length. With short shafts engineers try to control this motion using firm suspension, and while stiff springing and damping can prove effective at muting shaft effect, they also exact a price in suspension compliance.

The Nighthawk’s short-engine/long-shaft approach offers an elegant solution. The suspension is softer, more responsive especially under acceleration, and its driveline, void of nagging lash, is so well controlled you have to consciously remind yourself this motorcycle is shaft driven. Even backroad bozos who can’t get through a corner without chopping the throttle six or eight times will discover that the shaft imposes no limitations on handling. Expert sport riders will find the 700S surprisingly composed, thanks in part to its solid frame, fully adjustable suspension components and sophisticated running gear.

With a stout rectangular backbone measuring 75 by 45mm, supporting bridgework and heavy gusseting in the steering-head area, and needle bearings in the crucial pivots, the frame exhibits structural rigidity unrivaled by the old CB750F. The Nighthawk also flaunts progress made in eradicating front-end flex and excessive dive under braking; thicker triple clamps spaced farther apart on a steering head longer than the 750’s provide more stanchion support, and the Nighthawk uses stubby albeit longer-travel 39mm fork tubes in place of the 750’s 35mm twigs. Further driving the wedge between old and new technology are the Nighthawk’s four-position-adjustable TRAC anti-dive, a separate rebound damping adjuster and air caps (Honda recommends zero to six psi), and 16-inch wheels front and rear.

Though the rear suspension is a traditional twin-shock layout, the Nighthawk’s components offer both rebound damping and spring preload adjustment. Spring and damping rates are well matched to the front, and both ends have a wide range of adjustability. With the suspension system operating at its stiffest setting, the Nighthawk responds well to backroad roughhousing. Today’s front-row sport bikes will outrun the Nighthawk—some with superior power, others with superior cornering clearance (expert riders will grind through the 700’s pegs to the undercarriage)—but the 700S plays the plucky hellion role convincingly.

The Nighthawk’s fat tires, though prone to follow freeway rain grooves, provide excellent traction, its dual-disc, four-piston-caliper front brakes and drum rear are powerful, linear and two-finger (two-toe?) strong, and its steering is light and neutral from vertical to full-whoopee lean angles. During high-speed cornering, the Nighthawk feels taut, stable, never loose. Deeply scalloped surfaces will unsettle the suspension if the rider pushes hard, but the 700S always transmits early warning signals and never resists the rider’s command to tighten his arc halfway through a corner. The two-piece handlebars swivel to provide grip-angle adjustment and feature a moderate rise in relation to the seat. Though flat and wide from side to side, the seat has a forward slope which slides the rider toward the fuel tank, and its soft composition wears thin after and hour or so. Finally, the high and forward footpegs cramped our lanky testers during steady-state highway droning.

These ergonomic complaints aside, the Nighthawk is hard to fault. Despite ever-tightening EPA regulations, the 700S makes more power than the old 750, yet is smoother-running, requires far less maintenance, and delivers comparable fuel economy without the partial-throttle over-leanness that accompanied the CB750. Where the old bike relied on stiff-legged suspension to provide accuracy, the Nighthawk’s adjustable components offer both plushness and unflinching high-speed stability. In terms of steering response, maneuverability, sure-footedness, ease of operation, general comfort, and detail refinement, the Nighthawk is functionally superior to its pathfinding forerunners. Compared to Yamaha’s cruiser-styled XJ700 Maxims, the CB700S is more assertive and better-handling at high speeds, although the two Maxims offer virtues that bracket the Nighthawk; the two-valve XJ is $400 cheaper, the five-valver some eight horsepower stronger.

As a third-generation UJM, the Nighthawk illustrates great progress made in chassis and engine design, and, more significantly, the influence one has over the other. The UJM format remains, but 16 years of experience have changed the execution. Yesterday’s UJM’s integrated chassis and powerplants like so many marbles in a jar. UJM’s such as the Nighthawk achieve their integration by a process that locks power and handling, engine layout and chassis design together in an almost molecular bond. It’s this new principle that the Honda Nighthawk proclaims, and it is a far better one than the last.