Honda Cbr1000rr
Honda CBR1000RR
NEW BIKES 2008
A fresh look and new thinking punch up Big Red’s Open-classer
KEVIN CAMERON
AN ALL-NEW LITER BIKE IS ALWAYS BIG NEWS, AND THIS ONE is Honda's 2008 onward step. Its style is new, it's lighter and more powerful, and the people presenting it clearly expect it to be the new class leader. In common with Honda’s MotoGP bikes, the CBR1000RR’s performance theme is to be quicker and faster through being easier to ride, not harsher and more demanding. This concept began with the CBR900RR and then went racing with the V-Five RC21IV in 2002. Also in common with MotoGP machines, this CBR has traction control, disguised with the lawyer-lulling name of “Ignition Interrupt Control.”
New style themes are its MotoGP-like “dagger” seatback-slender and un-bulged by any exhaust pipes. The Spiderman III fairing is abbreviated as in MotoGP, shows a lot of engine, and is a thing of shark’s-tooth slots and ducts.
Up close, the bike is small and potent-looking. “CBR” has become a brand-within-abrand, which this machine further distills and concentrates. This design has been attributed to “an American, not long out of school,” who
spent a one-year internship in Japan. A fresh look can sometimes do what months of staring cannot!
Just as a car’s anti-lock brakes allow us to brake with confidence under a wider variety of conditions, so traction control has allowed MotoGP riders to more confidently run closer to the edge of tire grip. Traction control softens the effect of small rider throttle errors or of lowgrip pavement surface. Now that such systems have been perfected in racing, it is time to bring the same protection to everyday riders. While some systems in MotoGP operate as “throttle-by-wire,” Honda’s Ignition Interrupt Control is just what it says it is: a system that promptly modulates engine torque by cutting out cylinder firing events. Although not described in more detail in the information currently available, this almost certainly operates progressively, cutting an increasing percentage of spark as more torque reduction is needed.
Wheelbase is a quick-turning 55.4 inches, and rake and trail are 23.3 degrees and 3.8 inches. Wheels have three hollow spokes and the wide, track-inspired dimensions of 3.5 x 17 front and 6.0 x 17 rear. When you see rims 6 inches wide in trackside tire racks, they look like they came off of cars.
Travel of the 43mm inverted fork is 4.7 inches and that of the Unit ProLink rear singleshock system is 5.4 inches. Both offer adjustable spring preload and variable compression and rebound damping-with easy adjuster access. Swingarm pivot position is nonadjustable. Front brake discs are 320mm in diameter with radialmount four-piston Tokico calipers, and a single 220mm rear disc is fitted. Tires may be either Bridgestone or Dunlop radiais in 120/70 front and 190/50 rear sizes. That 190mm translates to 1XA inches.
Note that the shift mechanism is high on the left side, reached by a long vertical linkage rod. This indicates the modern practice of stacking gearbox shafts one above the other. This places more engine/gearbox mass forward, where it is needed to keep weight on the front wheel even during hard acceleration. For the same reason, the rider has been moved forward 10mm and lowered 10mm. Look at how far forward Nicky Hayden’s seatback is on the current RC212V MotoGP bike-for the same reasons.
Lightness and mass centralization directly enable machines to accelerate, brake and turn more quickly. Of special importance are parts that spin, and this CBR’s aluminum wheels and brake rotors are lightened. A battery 2.2 pounds lighter combines with a 1.1-pound lighter chassis, aluminum sidestand, hard-plated aluminum caliper pistons and titanium intake valves to pare off excess. Gone are long, rear-projecting pipes that resist turning movements, replaced by a cleverly packaged under-engine muffler that includes a power-widening exhaust valve and catalyzer. This muffler exits on the right but smoothly integrates into the shape of the belly pan.
The all-new inline transverse fourcylinder engine has a 76.0 x 55.1mm bore and stroke, and its big, blackfaced tach redlines at 13,000. Ti intake valves, controlled by nested spring pairs and driven by shim-under-bucket tappets, announce a goal of either higher rpm or more vigorous cam lifts to provide more flow area, more quickly.
Valve sizes are 30.5mm intake and 24.0mm exhaust in a 12.3:1-compression combustion chamber. High compression boosts engine torque. “Thinner” pistons, forged in high-strength alloy are coated with low-friction moly. They operate in Nikasil-plated cylinders in a removable cylinder block. Engine power is not revealed, but further information is promised. Assuming peak power at 12,500 rpm and current-state-of-the-art breathing and combustion, Ed forecast 178 crankshaft horsepower.
The intake system features Honda’s “Dual Stage Fuel Injection” with two injectors per 46mm stack-one below the throttle butterfly for prompt throttle response (fuel reaches the cylinders quickly), the other hovering above the intake bell in the “showerhead” position for higher-rpm operation (longer droplet time-of-flight to achieve full evaporation). Twelve-hole Denso injectors feature lightweight valve parts; quicker operation by such lighter valve elements increases metering accuracy because they spend less time between closed and open, especially at the crucial initial throttle opening. Upstream, the 9.7-liter resonant airbox has two ram-air inlets equipped with butterfly valves that “open and close depending on throttle opening and engine rpm.” This could mean the airbox has multiple torque-boosting resonant frequencies or simply that, like the exhaust valve, it neutralizes torque-reducing negativepressure resonances (all resonant elements, such as tuned intake, exhaust or airbox, have both positive and negative resonances). The goal in either case is wider, more usable power.
A slipper clutch is used. Its purpose is to prevent engine braking from dragging or hopping the back tire as the throttle is closed or from interfering with rear-tire grip as the machine is leaned over, decelerating, into turns. I tried to decode what is meant by “pressure plate doesn’t move from side to side like an ordinary slipper clutch” but am stumped. I’ll tell you more when I know.
The Idle Air Control Valve, or IACy is actually a motorized throttle positioner that not only maintains idle stability during warm-up, but also smoothes the bike’s response to choppy rider throttle movements. Cold-start and warm-up enrichment are scheduled into the programming of the PGM fuel-injection-there is no manual choke.
Another small mystery is “Intake ports use new shotpeening technology that improves power and torque characteristics.” That might mean that ports receive some hand cleanup, with grinder marks then smoothed by shotpeening. Or it might mean there is actually some flow benefit in the myriad tiny golf-ball-like dimples that shotpeening creates.
A new implementation of Honda’s Electronic Steering Damper is located behind the steering head, unseen beneath the tank cover as on the CBR600RR. The computer turns the damper on at speeds that require it and off at low speeds to make maneuvering easier.
A two-bulb reflector “line beam” headlight, LED taillights and LCD instrument readouts provide visibility and information. Four standard color schemes are listed, with a special 2008 limited color run of 500 or fewer in black/metallic gray.
Adventure calls.
