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It seemed all too familiar, traveling to Buttonwillow Raceway to ride a newly revised member of Honda’s CBR-RR sportbike family. This outing was akin to one a year ago when American Honda invited the moto-press to the 2.5-mile roadcourse flanked by farmland in the heart of California’s Central Valley to ride its second-generation CBR600RR. And just as with the 600, Honda has treated its two-year-old CBR1000RR to a midlife update, making it lighter and more powerful.
Judged by its own merits, Honda’s flagship repli-racer was already a highly capable platform and one of the best streetbikes among hardcore liter-class sportbikes. But it has also taken a beating from its lighter, more agile and more powerful class peers in track-based comparison tests. Honda has addressed all three of these points, achieving notable gains (or reductions) in each area. The overall result is a more exhilarating ride thanks to a claimed 17-pound weight loss, 3 percent increase in peak power, revised chassis geometry and sleeker bodywork, all of which has sharpened both the bike’s performance and looks. Perhaps the most attractive aspect of the ’06 RR is that these improvements carry only a $300 premium, with the price now at $11,299.
A tech briefing held the evening before we rode the new bike on the track seemed almost a formality. The RR features no revolutionary new systems branded with clever acronyms, nor are there any radical new production processes to tout; just plenty of attention to detail resulting in a few more foot-pounds of torque while grams shaved here and there add up to tons of enlightenment. A revised underseat exhaust (with titanium muffler core) attached to a lighter subframe account for a good chunk of the weight loss and improved mass centralization. More subtle revisions abound, such as downsizing the ECU to a brain small enough to be centrally located atop the airbox, shedding the unnecessary weight of a steel bracket used to secure last year’s control unit to the right side of the main frame.
While it’s difficult to get too worked up over lightened, hollow-core camshafts, the engine’s quicker rev response and a higher, 12,200-rpm redline (up from 11,650) should do the trick! The 998cc liquid-cooled inline-Four’s peak power gain is attributed to a number of factors starting with the revised shape of the ram-air ducts and a less restrictive grille offering improved airflow. The upper showerheads of the dual-injector EFI system have a new spray pattern said to deliver greater efficiency in feeding the reworked cylinder head’s straighter intake and exhaust ports. Combustion chamber volume has been reduced, yielding a power-producing bump in compression ratio that’s gone from 11.9:1 to 12.3:1. Altered valve timing and increased lift—on the intake side—also contribute to the boost in power, which now sees peak torque at 10,000 rpm, 1500 revs higher than before.
A tooth has been added to the rear sprocket, yielding greater acceleration without a sacrifice in top speed thanks to the engine’s extended rev ceiling. Refinements within the six-speed gearbox are twofold, with gear dogs undercut for a more positive engagement and widened to reduce drivetrain lash. The CBR bucks the current trend that sees the use of a back-torque-reducing slipper clutch on some of its classmates. In speaking with the CBR project leader, I learned that the added weight and cost was thought to outweigh the performance benefit of such a setup.
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