When Too Much is Never Enough

Honda CBR1100XX vs Kawasaki ZX-11 Source: Motorcycle Consumer News, April 1997


One-upmanship is a game that has been played by motorcycle factories since the very beginning. Early motorcycles were built primarily as transportation vehicles. Some were designed as freight- carrying machines which were equipped with sidecars, both for freight and for passengers. A few from several of the factories found their way into competition events. It was learned early on during the motorcycle's development that racing improves the breed, and that motorcyclists were keen to own the fastest machine available. This, of course, still holds true. Even if the chosen model isn't the fastest in that manufacturer's lineup, it is still considered to be of high quality, and therefore to be coveted and cherished. A sort of status symbol. In this case, the Honda CBR1100XX and the Kawasaki ZX-11 are the fastest machines in these, or any other manufacturers', catalogs, as well as among the most expensive.

Honda and Kawasaki each have many years of competing with one another for the title of the fastest street machine available. Honda's CB750 four-cylinder, overhead-camshaft roadburner appeared in 1969 and set the motorcycling world on its ear. Producing a motorcycle that was technically complicated, which did not leak oil, vibrated little, had outstanding brakes for the time and was extremely reliable made it an instant success. For its size, it was even a fairly good handling machine, although not agile enough to be considered in a league with the smaller, lighter British machines.

Earlier in 1969 Kawasaki joined the high-performance contest with the introduction of the 500cc two-stroke (H-1) Mach III. Fast, with extremely peaky power delivery and a voracious appetite for fuel, the H-1 was not a popular machine with the motorcycling public, but its reputation far preceded it. The racing version, the H-1R, was a force to be reckoned with in AMA national roadrace competition. Both machines were extremely quick in 1969 terms: the Honda turned the quarter-mile in 13.38 sec at 100.11 mph while the smaller Kawasaki streaked through the traps in 13.20 sec at 100.22 mph. These times/speeds may seem somewhat pedestrian now, but considering they were attained with standard, production machines nearly 30 years ago makes them impressive indeed. It wasn't too much then, but it wasn't enough, either!

Kawasaki took the performance lead in 1973 when it introduced the 903cc Z-1. For the next several years it had no chalengers for the crown, but Honda was on the move. Cycle World magazine tested the new Honda CBR1000 against the just-introduced Kawasaki ZX-11 in 1990, and although its 156 mph top speed and 1/4-mile run of 11.20 sec at 123.96 mph was slower than the Kawasaki's 176 mph top speed and 10.46 sec at 134.5 mph run, Honda showed that it was serious about playing catch-up. It quietly developed the sophisticated CBR1100XX over the past few years to be a world beater, and it looks like Honda hit the mark.

Form Follows Function

The CBR1100XX looks like it's going 100 mph while parked. The narrow, droop-snoot front of the fairing and air-management ducts, and shape of the front fender, show that Honda is serious about getting the best wind penetration possible. Because the headlight area is so small, Honda was forced to develop a new headlight assembly with the high-beam light mounted above the low beam, and it provides the finest light we have seen on a motorcycle. But the fairing on the ZX-11 is also very very efficient, according to Bob Liebeck, Ph.D., of McDonnell Douglas Aircraft Co. "Looking at the two machines straight on, and with no aerodynamic measurements, the fairing seem to be pretty equal," he quipped. But the fit and finish, if not the rider protection of the Honda get the nod. Due primarily to its styling and high performance capability, the Honda is called the Blackbird in Europe and Canada. There is even a video that will be shown primarily in Honda dealers' showrooms that shows a CBR1100XX performing on an aircraft runway with a Lockheed SR-71 Blackbird.

Sophisticated Engine Design

Kawasaki has had six years to develop the ZX-11 engine, and it has settled on bore/stroke dimensions of 76mm x 58mm, equalling 1052cc, with four valves set atop each cylinder. These provide an included angle between the intake and the exhaust of a mere 30 degrees, indicating a compact combustion chamber. Compression ratio is 11.0:1. A quartet of 40mm carburetors reside inside the Kawasaki Twin Ram Air Induction System airbox, which is pressurized with air taken from the front of the fairing area. Honda's approach to the induction equation is not as elaborate, but is certainly effective. A glance at the front of the XX's fairing shows air inlets beneath the headlight, but these lead o the oil cooler and to a "ceiling panel" that isolates the airbox from hot air produced by the radiator. Under the air inlets beneath the headlight is a maw that lead cooling air to the radiator. But once the fairing beneath the front of the fuel tank, and the tank itself is removed, there appears the outline of an airbox. Here are a couple of areas where hoses from a fresh air source at the front of the fairing could be connected. Honda was able to get ZX-11 performance without resorting to a pressurized airbox, so one was not included. Besides, it always helps to have an improvement for next year's model, although that sounds more like something GM would do - not Honda.

Honda's solution to getting good horsepower from the CBR1100XX engine took many of the same paths as Kawasaki did. Bore/stroke dimensions of 79mm x 58mm show a 3mm larger bore than the Kawasaki with a resultant size advantage of 85cc, hardly significant as far as performance goes. But the unitized construction of the cylinder block and the cylinders provides a stronger and more rigid assembly than bolting the two items together. This approach equals potentially more power due to less flexing of internal components. The engine, which weighs 22lbs, less than the 998cc CBR1000F powerplant, is canted forward 22 degrees and also produces approximately 22 more horsepower, due in part to a more efficient path for the fuel/air mixture to follow into the valves and combustion chamber. As the astute reader would guess, maximum horsepower ratings of the two machines are nearly the same: Kawasaki's ZX-11 recorded a maximum of 133 rear wheel horsepower at 10,500 rpm. The Honda CBR1100XX was literally a tick behind, recording 132.9 horsepower at 9500 rpm. The maximum torque readings were almost the same as well with the ZX-11 showing 78.8 ft. lb. at 8500rpm. Honda's peak of 78 ft. lb. of torque occurred at 7500 rpm.

Also new for the Honda CBR1100XX is the fitting of dual counterbalancers, a first for a sports machine of this size. Vibration has always been a bugaboo of large fourcylinder engines, but there are several ways of controlling this unwanted phenomenon. These include the use of a rubber-mounted engine, a single balance shaft, or both, but none of these options is entirely satisfactory.
A rubber-mounted engine loses favor because it cannot be used as a structural (read;strengthening) member of the frame, and merely mounting the footpegs and handlebars in rubber can cause imprecision and vagueness in the machine's handling.
Quelling the vibration at its source, the engine itself, is the only true method of eliminating the most annoying, secondary vibration. Here, Honda has borrowed from automotive technology with the installation of two, counter-rotating balancers, one almost directly beneath the crankshaft near the front of the engine and another, rotating in the opposite direction, placed high in the crankcase behind the cylinders.
The CBR1100XX is not "as smooth as an electric motor," but the silkiness of its power delivery rivals that of any four cylinder four-stroke engine we've ever tried.

it must be mentioned that the Kawasaki ZX-11 is also fitted with a counterbalancer, but it is of the simpler, single-shaft variety. Although not as velvety smooth as the Honda's engine, the Kawasaki's shudders only slightly at low engine speeds, below 3000 rpm, where it not only pulls with more emphasis than the Honda, but also makes authoritative, although muted, sounds from the intake and exhaust systems...beautiful sounds, indeed. However, the ZX-11 suffers what feels like a lean condition when approaching 4500 rpm using moderate throttle. It makes one wonder if the ram-air system for the carburation is fully debugged.

Ergonomically, both machines are quite comfortable, having handlebars that are higher than true clip-ons and footpegs that are lower and farther forward than those on true racer replicas. Due to the moderate wind protection and low vibration levels, and with fuel tanks that hold in the neighborhood of six gallons, both machines can be ridden for long periods of time without undue rider fatigue.
The distance between the seat and the handlebars is greater on the Kawasaki than on the Honda, making it less comfortable for a short rider. Good handling motorcycles have become commonplace in the past few years. Increased awareness of the needs of the frame's design, as well as the availability of materials needed to manufacture chassis that can be afforded on a production motorcycle, have given riders a proliferation of really fine handling machines. But until recently, most of these motorcycles have been of the small-to-medium capacity offerings. Both the Honda, with its massive Triple-Box-Section aluminium frame, in which the engine/transmission unit literally "hangs" in front of the swingarm, and the Kawasaki's Twin-Spar Aluminium Perimeter Frame, provide strength to keep both ends of the motorcycles in line while permitting the front and rear suspension components to do their jobs.

Suspension

Honda's 43mm cartridge-type front fork is a direct descendant of the 41mm unit used for several years on its enormously successful CBR600 sportbike. However, while the forks fitted to the 600s are adjustable for spring preload and rebound damping, the 1100's cartridge-type unit is not adjustable. Because of somewhat hars initial resistance of the sliders to travel up the fork legs, there is some hobby-horsing when riding over pavement slab edges, but the cartridge-type units provide some of the best control we've seen while traversing rough pavement at speed. Hitting a known bump by mistake going into a favorite turn while climbing one of our frequently traveled mountain roads, strengthened our appreciation for these forks.
When this bump was encountered in a turn at about 60 mph with the bike leaned over significantly, the front wheel was dutifully followed by the back wheel in a display of almost unbelievable aplomb and reassuring composure. The handlebars moved with a nearly imperceptible twitch while the rear end of the motorcycle squatted slightly, as if to say, "Ex-kuze me!" The single rear shock absorber features spring preload adjustment and stepless-adjustable rebound damping. Rear wheel travel is adequate at 4.7".

Kawasaki's suspension package is more adjustable. The conventional 43mm front fork offers a rigid package for precise cornering and there is a threaded spring preload adjuster and a four-way valve to allow rebound damping toe be altered.
But there is still too much compression damping over small freeway section lines. This tendency could be reduced, but there is the possibility of losing sufficient compression damping and suffering excessive fork dive from large pavement irregularities as well as from heavy front brake application. The rising-rate rear suspension system on the ZX-11 works well for general riding and features both adjustable preload and four-way rebound damping adjustments.

Braking

Of paramount interest to the sportbike rider is the effectiveness of the motorcycle's brakes. Machines that can travel at speeds approaching 170 mph should have the best available.
The Kawasaki is armed with twin four-piston calipers squeezing 320mm rotors up front, with a twin-piston caliper embracing a smaller 250mm disc on the rear wheel. The brake pads fitted to the Kawasaki seem to be fairly soft because of their sensitivity to subtle rear brake pedal and front brake lever application, and after many hard stops from triple-digit speeds, the brakes begin to show signs of fading. However, this should be of little concern to most mortals who purchase the ZX-11.

The Honda's braking system is much like the majority of sport motorcycles being offered for sale today, but there is a significant difference which proved to be something of an enigma, and caused more than a couple of arguments among the MCN staff members.
A version of the Linked Braking System on the CBR1100XX was first introduced on the 1993 Honda CBR1000F. It was not a very popular addition to the motorcycle, however, and many CBR1000F owners disabled the system to enable the return to a normal braking system. The system was taken off the CBR1000F, developed more highly, and now appears as an option on Honda's ST1100 and stock on the 1997 CBR1100XX.

Linking the front and rear brakes has been de riguer on automobiles since the early part of this century, but hooking both brakes together on a motorcycle has only been attempted by Moto Guzzi in a much simpler system. The reasons are perhaps not as cleat-cut as saying that a rider might want to use just one of his brakes. Both brakes should be used in concert to provide the best stopping distances in most cases. Some racers use very little or no rear brake because the front brakes are so powerful that the rear wheel becomes light enough to become almost ineffectual when braking in a straight line from high speeds. Few people will argue this point, but the fact remains that the rear brake is still very effective on motorcycles at reduced, or even high speeds, especially when turning, and therefore maintains its value in the stopping equation.

Several reasons for disliking the first linked braking system on the CBR1000F have now been addressed, and the new version is vastly superior. Many hours of computer time and real life testing have been spent suggesting and then measuring brake bias settings for both the front and the rear brakes. In the current LBS system, both the front and rear brakes are engaged when either the front or the rear brake controls are activated. This experimentation has led to meeting the needs of a high-performance machine like the CBR1100XX a well as a more sedate sport-touring machine like Honda's ST1000.

Handling

Of course, engine and braking performance are of little value to the sport rider if a machine doesn't handle, and this is where the bikes reveal their different characters. As the Volkswagen ads used to say, "It's not how fast you go, but how well you go fast."
At walking pace, as when maneuvering in a parking lot, both machines feel somewhat truckish and ungainly. But at speeds of 10-15mph the Honda, especially, feels like it has become a much smaller mount, such is the low amount of effort required to handle it. The Kawasaki has a much heavier feel. It requires more firmness with handlebar movements to make directional changes. What is incredible about both machines is their ability to handle bumps while traveling at speed, either in a straight line or when negotiating curves. As stated earlier, the progress in frame geometry and construction, coupled with the strength and adaptability of the suspension system, aided by the Bridgestone BT57 tires on our XX, make this machine a real pleasure to ride fast, anywhere. Honda will also be fitting Dunlop and Michelin tires to some of the CBR1100XX machines imported to the U.S. The Kawasaki also had a solid, stable feel, but it didn't want to turn in as fast or as precisely as the XX.

Both bikes feature spacious seats with plenty of room for both rider and passenger, and the suede-look material covering the Honda's seat precludes the rider's sliding around during acceleration and braking.

The two machines also feature good six-speed transmissions which are usually reserved for machines no larger than 600cc because they have narrow powerbands that require that the engine be kept in its higher rpm range to develop enough power for spirited riding. The 1100s, on the other hand, each develop in excess of 55lb. ft. of torque from over 3400 rpm and hardly need six-speed transmissions to perform in a spirited fashion...but we're sure glad they come so equipped when an open road lies ahead.

Conclusion

So what we have here are two different but excellent 1100cc sport machines. Their maximum power outputs and torque readings are within a fraction of each other. The real big difference between the two machines is their weight: the Honda CBR1100XX is some 48lbs. lighter than the ZX-11 --a fact that is obvious at any speed. You'll have to decide what that's worth to you. However, the Honda's 10.24 sec. at 134.52 mph quarter-mile time with a top speed of 170 mph is only a scant fraction faster than the ZX-11's 10.43 sec. at 131.39 mph quarter and its 169 mph top speed.

An incredibly unusual difficulty slowed the progress of the test somewhat as the big Kawasaki expired on the way to its first top speed run while accelerating through 120 mph. The sudden stoppage of the engine was caused by an uncharacteristic connecting rod failure. Usually, the only reason a stock engine would succumb to this malaise would be from lack of oil, so Kawasaki Motors Corp. replaced the engine without question after it had inspected it.

The other big difference between these machines is the price. The $11,499 Honda is $900 more than the $10,599 Kawasaki. If your riding leans more toward the "sport" side of things, the superior CBR1100XX is well worth the extra dough. But is sport-touring is more your style, the ZX-11 is also an acceptable choice.


By: Big Joe Coonan