Issue 128 : April - May 2003
MAG News
Helmet Cases
Yamaha YZF-R6
Honda CBR600RR
Screamin' Eagle
Cycling Zealot
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MAG News
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Red Mist
It had been a fast and frantic day aboard Honda's hottest ever production middleweight. In the morning the Estoril circuit, near Lisbon in Portugal, had been wet, and the CBR600RR had impressed with its flexibility and precision. For my last session there'd been dry tarmac almost all the way round, and the RR had been in its element: screaming down the pit straight with its motor revving to 15,000rpm through the gears; slicing through bends with all the agility and control you'd expect from such a focused machine. All that had given me a good idea of the new CBR's ability, and had suggested that Honda's decision to produce a cutting-edge 600-class four, after 17 years of more versatile and hugely successful models, has resulted in a stunning bike that will be a hit on road and track. The view of the RR's cockpit as the tacho needle swept round the dial was firmly embedded in my memory, as was its flickable feel through the track's tighter turns, and the blend of wind roar and muted howl from the single silencer in the shapely tailpiece. But for all my laps on the CBR, it was an unexpected comment from Hiroyuki Ito, the bike's chief development engineer, that had given most insight into the bike and the thinking behind it. "We developed the RR in a completely different way from any model in the past," said Ito, a veteran of this bike's less radical predecessor the CBR600F Sport. "In the past Honda has always developed a road bike, then modified it for racing. But with the RR, we first built a prototype racer, then gave it to the production department." When I asked if this new approach worked well, Ito laughed and gave a thumbs-up sign. "Oh yes, it was a big success. When you work the old way there are many restrictions. But if you develop the racer first you can be much more performance oriented, so it is good for this type of bike. It can be difficult for the production engineers; for example the exhaust system on the RR required very high accuracy parts. Ito and his team started work on the RR project two years ago, at the same time as development of the RC211V grand prix racer began. (As to whether the RCV will give birth to a roadster soon, Ito wasn't saying.) That bike's 990cc V5 engine is very different to the CBR's familiar 599cc, four-cylinder unit, of course. But the two development teams shared much information, and the influence of the all-conquering RCV is clear in the RR's aggressive shape and in the design of its frame and swing-arm, as well as in that high-level exhaust system - and in the bike's take-no-prisoners attitude. The RR looks fast and racy from every angle, including from a rider's seat that is 70mm further forward than that of the old CBR. Sitting on the bike for the first time, and reaching over the dummy tank (gas lives low, mostly under the seat) to the low bars, I felt as though I could almost look over the top of the stubby screen at the front wheel. That said, despite being very tall I didn't find the bike cramped, and could tuck down behind the screen, as well as having an uninterrupted view of the new instrument console with its round tacho and digital speedometer. The early bad weather was frustrating, but at least it gave an opportunity to make the most of the RR motor's welcome degree of flexibility. Having recently ridden Kawasaki's rev-hungry new ZX-6R, I'd expected a similarly dramatic burst of acceleration at the top end, with a contrastingly flat feel until the tacho needle reached about 10,000rpm. Despite its slightly smaller capacity than the 636cc Kawa, the CBR is not like that at all. Sure, the best power is up near the redline; specifically at the 13,000rpm mark at which the peak output of 115bhp is produced. But the Honda made life easier with a very linear power delivery. While I scrubbed and warmed new tyres for the first couple of laps, the motor pulled cleanly from as low as 4000rpm, with a superbly precise response from the updated fuel-injection system. And from that point it simply carried on getting stronger and stronger, staying very smooth all the way, until the useful rev-warning light on the dashboard said it was time to change up. (It's a shame there's no ZX-6R style lap timer too.) Of course for maximum acceleration it was necessary to keep the revs high; and the Honda certainly motored when I did. On a slightly downhill straight I would have seen 150mph on the digital clock if I'd been able to keep looking down just a fraction longer before concentrating on the following right-hander. Other rivals including the ZX-6R and Yamaha's uprated YZF-R6 pack plenty of punch, too, but Honda's engine is a seriously strong and flexible motor that's as well suited to the road as to the racetrack. That is also true of a chassis that delivered superbly precise and light handling, and also showed plenty of stability and a superbly neutral feel. How much of that is due to Honda's new frame with its RC211V-style low fuel tank and Unit Pro-Link design isolating forces from the frame, I'm not sure. What can be said is that the RR's light weight (169kg dry) and the low centre of gravity contributed to a flickable feel that kept the bike unruffled even through ultra-quick direction changes.  On its standard settings the suspension was a bit soft for my 14-or-so stones once the surface dried and I could really start flicking the Honda around. Adding a touch of preload and rebound damping at both ends made things better and added some ground clearance; the right footrest tip had been the only thing to touch down before that. The front end still moved around slightly under hard braking, but I'm sure a little more fine-tuning would have sorted that, given more time. Honda hasn't followed Kawasaki's example and fitted racebike style radial calipers, but these four-piston Nissins worked so well that this wasn't a drawback, except perhaps in terms of image. I was also very impressed with the Michelin Pilot tyres. The road compound rubber gripped well in the dry, and even coped with the damp stuff. For track use some riders will doubtless prefer softer rubber, but even this sportiest of Honda middleweights is likely to find most of its miles covered on the road. It lacks many of the rider-friendly features of its predecessors, but does have brighter headlights, a clock and fuel gauge in the dash, and a HISS immobiliser, plus the small pillion seat with storage space underneath. Some other useful bits such as a centre-stand and pillion seat cover are available as Honda accessories. So too is a race-kit that takes the RR to Supersport specification, including cams, thinner head gasket, close-ratio gearbox, radiator and exhaust system. The fact that those racing parts are being sold through Honda dealers for the first time emphasises how much this model represents a change of image for the long-standing CBR600. By no means all the virtues that have made this bike's predecessors so successful over the years have been abandoned. For all the Honda's new-found love of revs, it pulls through the midrange in notably clean and smooth style. For all its quick steering, it remains stable and easy to ride. For all its racy initials and new-found aggression, this bike is still very much a CBR too. But there's no doubt that most riders' overriding impression of the CBR600RR will be of its pure, exhilarating speed, on straights and though bends alike. Honda has gone all-out to build a 599cc four that will be competitive on the track both in standard form and in Supersport racing.
CBR600RR Tech Honda claims that its new middleweight has the DNA of the five-cylinder RC211V, and it's hard to argue despite the CBR's 16-valve, liquid-cooled four-cylinder engine layout. The motor is comprehensively reworked, but retains the old model's 67 x 42.5mm dimensions as well as its 599cc capacity. External dimensions are reduced, by relocating the starter motor and alternator to save width, and with a stacked gearbox arrangement that makes the unit shorter from front to back. Angling the exhaust ports downwards by an extra 30 degrees gave room to move the engine forward by 9mm. This in turn allowed the swing-arm to be 43mm longer, for improved traction. Other engine changes include lighter slipper pistons, "nutless" conrods as seen on the SP-2 V-twin, and a new "dual-pivot" camchain tensioner that uses a second, smaller blade at the top to reduce the chain's surge when the throttle is blipped. The motor is fed by a new dual sequential version of Honda's fuel-injection system. This uses a second set of injectors, positioned in the roof of the airbox and working with the conventional injectors in the intake ports. The second set come into play only at high revs, when the conventional injectors' location does not allow enough time for fuel to be fully atomised in the high-velocity air stream. In conjunction with other changes including a more sophisticated ECU and the "centre-up" stainless steel four-into-two-into-one exhaust system, the result is a maximum power output of 115bhp at 13,000rpm. Chassis innovation centres on mass centralisation, with a frame that is new both in its layout and construction. The bike's weight distribution is changed by moving the rider forward by 70mm, and by holding the fuel low down, as with the RC211V. Handling characteristics were also fine-tuned by increasing torsional stiffness around the steering head, and reducing it slightly at the centre. Honda says this gives a lighter feel in quick direction changes, and aids wheel tracking over bumps. The main frame sections are made by a new hollow die casting process, instead of extruded as in the past. Using a ceramic coating on very thin interior mould sections allowed these parts to retain their strength at high temperatures and pressures. This allowed Honda to produce die-cast frame sections with a width of 2.5mm, compared to 3.5mm previously, saving weight and giving new design options. The higher quality of the castings makes them easier to weld, allowing the RR frame to be constructed of nine welded sections. Front suspension is by 45mm cartridge forks of the right-way-up variety. The heavily braced swing-arm is much more substantial than its predecessor, and owes its design to Honda racing developments. Like the RC211V, the CBR uses a Unit Pro-Link rear suspension system that compresses the shock using only the swing-arm, rather than feeding forces into the frame. Front and rear 17-inch wheels are lighter than their predecessors, while the front brake discs, which are gripped by four-piston calipers, are increased in diameter from 296 to 310mm. Roland Brown  |
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MAG member Roland Brown tests Honda's latest performance middleweight, the CBR600RR.
Judging by my first ride and the initial reactions in the first back-to-back tests, it looks as though they've succeeded. The RR is a superbly stylish, fast, sophisticated machine that heralds a new era of race-developed design not just for the CBR600 but also, it seems, for high-performance Hondas in general.