Honda CBR 900RR Fireblade

Overview

A 1mm larger bore saw the FireBlade’s capacity increased to 918.5cc and the seating position was more relaxed, with 10mm taller bars and seat height. The chassis was also beefed up and the fairing redesigned.

• The Blade’s drag-reducing front mudguard was the same design as the one on Honda’s NSR500 GP bike.
• Phillip McCallen won the 1996 and 1997 Production TTs on the Blade.

When Honda unveiled the CBR900RR in early 1992, it let loose a backroad weapon that was light years ahead of its time. Still, the battle for class supremacy marches on, and the standing never last long in a war zone, so Honda has rearmcdlhc '96 CBR900RR.

Since its introduction, the CBR's liquid-cooled, 16-valve motor has been the lightest, most compact open-class inline-four available. Last year, a revised gearbox with improved shift action marked the powerplant's first major update. Now, a host of engine-related performance improvements joins an even slicker-shifting close-ratio six-speed box.

Topping the list is a displacement increase, from 893cc to 919cc. Bore is up one millimeter to 71 mm, while stroke remains fixed at 58mm. liven with the larger bore size, Honda was able to maintain bore pitch, and therefore the width of the one-piece cylinder/crankcase, by using a refined cylinder-sleeve insertion process. New slipper-skirt pistons fitted with slightly thinner rings reduce friction and minimize weight gain. Compression is up slightly to 11.1:1, and the cylinder deck now has an aluminum face for an improved seal with the head.

To meet the demands of the engine's increased power output, Honda strengthened the crankshaft and powertrain. Big-end bearing diameter grew 0.5mm to 36.5mm, and the crank's counterweights were redesigned for increased strength and rigidity. A lighter and more compact alternator keeps crankshaft inertia down, in addition to improving left-side cornering clearance. There also is a new plate clutch and lighter #525 drive chain.

For smoother, quieter operation, the shift components are refined, and an all-new, two-piece "floating" clutch cover was added. A convenient oil sight glass eliminates the previous dipstick, and for improved response throughout the powerband, the ignition system gets a new three-dimensional map with a CBR600F3-like throttle-position sensor. Rounding out the engine updates are revised gearbox ratios in all but fourth gear, and a curved radiator said to provide the same cooling capacity as the previous component but with a reduction in weight and frontal area.

Start-up was never a problem, even on cooler mornings, and carburetion is crisp, a credit to the precisely jetted 38mm Keihins. While never an annoyance, engine vibration is always present. Below 5000 rpm, little more than a tingle seeps through the handlebars and rubber-covered foot-pegs. Spin the engine into the heart of its power curve, however, and the increased vibration keeps pace with the rider's quickening pulse.

On the dyno, the bike produced 117 peak horsepower at the rear wheel, 3 up from last year. More importantly, there's as much as 5 additional horsepower throughout the rev range. This, in addition to a claimed 3-percent reduction in drag and an 8-pound drop in dry weight, promised better real-world performance.

As with previous models, the 900RR's short, 55.2-inch wheelbase made dragstrip launches an exercise in wheelie control. Even so, the bike sprinted through the quarter-mile in 10.54 seconds with a terminal speed of 131 mph; last year's bike turned in a 10.67-second run at 131 mph. At our top-speed site, the '96 model registered a blistering 161 mph, up 3 mph on its predecessor.

Such straight-line speeds are effortless thanks to rock-solid chassis stability. Add 600-class agility (no surprise, considering the 900RR weighs less than any frontline 600) and you've got one of the most exciting rides money can buy. From the outside, the frame looks the same as last year's, but closer examination reveals an entirely new design. Internally, the extruded aluminum main spars have a triple-box cross section instead of the previous four-box design. Wall thickness was reduced slightly, while the beams themselves are one millimeter wider. Overall frame width was reduced half an inch.

Previously a hollow casting, the swingarm-pivot plate is now gravity die cast, and its backside bears an intricate web of reinforcement ribs. The aluminum swingarm received similar treatment in the form of modified main-spar extrusions and a revised cross-brace constructed of larger-diameter, box-section tubing.

Handling and chassis control also benefit from the use of all-new suspension internals, which offer greater response and a wider range of damping adjustability. AS before, the 45mm cartridge fork and remote-reservoir-equipped rear shock are fully adjustable with tools provided in the under-seat kit. Setting the damping rates near full-soft provides a compliant ride best suited to in-town use or moderate canyon riding. Firmer settings-about one turn out from max on both rebound and compression at both ends-deliver excellent control and feedback for high-performance road and track work.

The 900 has the distinction of being the first production motorcycle to wear Bridgestone's all-new BT-56 radial. The 180/55-17 rear features a jointless monospiral casing said to offer superior shock absorption. Improved dry- and wet-weather traction is also claimed, as is shorter warm-up, better wear characteristics and reduced weight compared to the previous BT-50.

Back-to-back comparisons with a '95-model CBR900RR at Willow Springs Raceway provided opportunity to experience the engine and chassis changes firsthand. Corner exits that had the year-old bike hinting at head wag simply didn't rattle the new machine. Cornering clearance is also better; even at extreme lean angles, only the footpegs touched down-the leading edge of the right side-mounted muffler on the '95 bike kissed the asphalt during agressive cornering.

Since race-compound Bridgestones were not yet available, we lapped on the street-biased, original-equipment rubber. Front-end feel is much improved, but racetrack cornering speeds caused some squirm, the result of the rear tire's more pliable casing flexing under extreme cornering loads (this is not a problem on the street, where tire loads are far less than those achieved on the racetrack). Even so, the '96 model lapped in 1:31.01, eclipsing its predecessor's best, same-day time of 1:32.46.

Ergonomics are also improved, the most significant change being the revised gas-tank shape. Essentially, the top of the tank is lower and the side knee reliefs are deeper, giving the bike a more compact feel. For more natural hand placement and a slightly reduced reach, the clip-on handlebars were rotated 5 degrees rearward. For greater leg room, the seat was raised 0.4 inch, necessitating an equal rise in handlebar placement. Even with the changes, the 900RR remains a hard-edged race-replica. The saddle is nicely padded and roomy, but spend much time droning down the interstate, and arms, back, shoulders and wrists begin to ache.

Honda calls the 900's new front fender revolutionary. The shape, it says, lightens handling effort and reduces front-end lift at higher speeds. Rider comfort is also affected because the fender is designed to direct incoming airflow up the face of the fork guards into the cockpit. This creates a high-pressure zone behind the windscreen, which helps deflect air flowing over the screen for reduced turbulence and helmet buffeting.

Such attention to detail is apparent throughout the bike. Fit and finish is first rate. Instruments and indicator lights are easily read, day or night. The controls and switchgear are laid out nicely and, functionally, are smooth as silk. Revised bodywork-only the upper cowl, windscreen and lower interior cowl inserts remain unchanged-benefits from gas-assist injection, which allows for thinner, lighter and more rigid panels. The fairing-mounted mirrors offer a clear rear view, and the fuel petcock is easy to reach while on the fly.

Considering the company it keeps-or beats on the performance charts-the CBR900RR is still a bargain, even at $9799. No, it's not some rare, show-stopping exotic, but it doesn't need to be. Pound-for-pound, dollar-for-dollar, you won't find a better big-bore sportbike.

Source Cycle World 1996