The year 2004 brought big changes to the CBR series. While the true home of the CBR900RR and its successors remained the street, the potential of these super sport bikes had come to the attention of competitive riders, who were beginning to ride CBR bikes more and more in races. Also, the Superbike World Championship changed its regulations to allow 4-cylinder engines up to 1,000cc in displacement. As a result, Honda decided to change its base motorcycle for Superbike from the VTR1000 with a V2 engine to a CBR bike with an inline 4-cylinder engine. The seventh-generation model would become the first in the series to be designed with racing as part of the equation. Thus, the engineers’ challenge was to create hardware that was completely at home on the street while also competitive in a racing environment.
At the same time, Honda’s 4-stroke 990cc RC211V racing motorcycle was sweeping away the competition in MotoGP, which is the highest class in the Road Racing World Championship Grand Prix, the premier championship of motorcycle road racing. Seeing the RC211V as the key to achieving success on both the street and circuit, the development team leveraged the advanced technologies of this racing machine in developing the CBR1000RR.
Former Honda Racing Corporation (HRC) works rider Hikaru Miyagi: Since the Superbike World Championship changed its allowed displacement to 1,000cc, Honda decided the seventh-generation 2004 CBR model would become the base vehicle for that competition. So displacement on the specification sheet went up, and the new model received numerous advanced technologies directly from the MotoGP racing machine. I saw it as a model that took on competitors in a frontal attack. The name of the bike changed to CBR1000RR, and it became a model that did not entirely fit the pattern established by its predecessors.
Final assembly team leader Kyoichi Yoshii: That’s right. When the Superbike World Championship changed its spec to four cylinders and 1,000cc, we designed the new CBR with this competition in mind. Among the development team members, however, there were those who said that CBR bikes were not intended for racing. And yet, up until that point, riders had used CBR bikes not only for getting around town and sporty riding but also for racing. Taking that into consideration and the fact that we’d be adopting cutting-edge technologies from our MotoGP racing machine, we felt that there would be some substantial merits to the new approach.
Miyagi: The RC211V was an incredibly easy bike to ride. For a racing bike, that is, but it really was amazingly easy to handle, and it was comfortable, too.
Kyoichi Yoshii: When we started developing the CBR1000RR, I had the opportunity to ride both the NSR500, which was for the old 500cc class, and the RC211V, which was for the new MotoGP class that replaced the 500cc class. When I took off on the NSR500, I had to slow down right away because of my level as a rider. If I didn’t stay focused, the front end would try to lift off the ground, and there was really no way to enjoy accelerating on the bike. On the RC211V, however, I was really surprised to find that I could keep giving it more throttle, just as if I were on a regular sport bike. What was even better was the incredible amount of control it offered. It reminded me of a particular scene from Grand Prix racing—when Kevin Schwantz on his Suzuki RGV500-Gamma accelerated into the spoon curve at Suzuka Circuit, making skid marks as he went. That scene floated up into my mind, and I felt as though I was about to recreate it. I wanted to deliver this same feeling to all of our customers. It really was this feeling of fulfilling a dream.
Miyagi: There could be no greater source of inspiration than the RC211V, could there? The timing was really great for you to make all kinds of changes.
Yoshii: Whether you’re raising engine power or making other changes, you’ve got to adjust the entire body of the motorcycle to ensure total control. The RC211V provided us with the perfect image of how this is done. We had the chance to leverage this in a commercially produced vehicle and redesign the body, the engine and everything else. The other manufacturers were all offering 1,000cc super sport bikes of their own. So we thought that now was the perfect time to use our most advanced technologies and create a super sport bike in the Honda tradition on which riders could enjoy sporty riding with the highest level of enjoyment and peace of mind.
The switch from 2-stroke to 4-stroke engines in MotoGP meant that the new bikes had vastly different characteristics from the old, such as higher vehicle weight and increased engine braking. In order to give riders total control over the new 4-stroke bikes, it was necessary for manufacturers to rethink their design completely. Honda responded by pursuing at the highest level the characteristic that is perhaps the essence of a racing motorcycle—concentrated mass—and designed the body of its new bike to counteract the rear wheel sliding caused by strong engine braking. One technology that was crucial in the implementation of this vision was the new Unit Pro-Link rear suspension.
Miyagi: We were talking about how Honda applied the technologies of the RC211V to the new CBR1000RR. The revolutionary Unit Pro-Link rear suspension was one such technology. As the person responsible for suspension design, what would you say were the merits of the Unit Pro-Link in the new model?
CBR1000RR suspension design team leader Masayuki Fujita: Technically speaking, it’s true that the Unit Pro-Link was a part of the suspension, but it had a more important effect than its role as a suspension part or swingarm.
Miyagi: What was the effect?
Fujita: If we’re talking about just the suspension, then using the Unit Pro-Link increases the weight of the swingarm and unsprung parts. But the benefit of the Unit Pro-Link was that the cushion unit didn’t need to be supported by the frame. This difference increased the freedom of frame rigidity, allowing us to create a design that prioritized rigidity in the pivot area of the frame.
Miyagi: I see. So we’re not talking about how just the suspension or frame works by itself but instead about a technology that has an effect on the entire finished vehicle. I guess that means that while you as the suspension designer had quite a tough time of it, the frame designers were extremely happy, right?
Fujita: Yes, without putting forth any effort, they got a more lightweight frame. [Laughs.] Even though the suspension gave us a tough time, the use of the Unit Pro-Link allowed the frame to be designed with a great deal more freedom. As a result, we were able to realize a higher level of turning performance and overall stability than ever before.
Fifth-generation CBR900RR (CBR929RR) Assistant LPL Kenji Hasegawa: In previous models, there was an upper cross-pipe to which the suspension was attached, but now the fuel tank could be positioned there, resulting in a greater concentration of mass and a more optimal moment of inertia.
Miyagi: This also connected with your goal of giving the 2000 and 2002 models a lighter riding feel without increasing rigidity. It’s true that the CBR1000RR was a bit heavier than its predecessors, but the greater freedom of frame design made possible a vehicle that had a lighter riding feel than one would expect from its weight.
Fujita: That’s correct.
Miyagi: In terms of new technologies on the CBR1000RR, the Honda Electronic Steering Damper (HESD) was fantastic. One day I borrowed the CBR1000RR used for PR at Honda’s Aoyama headquarters, and I got on the Metropolitan Expressway. This expressway has some rough patches, one has to look for gaps in the traffic flow in order to change lanes, and it just isn’t an easy road to ride on by any standard. I was really surprised that, even on this expressway, the CBR1000RR was so easy to ride that it didn’t feel like riding a high-powered super sport bike at all.
Seventh-generation CBR1000RR Large Project Leader (LPL) Hirofumi Fukunaga: It really makes me happy to hear you say that. We really wanted riders to be able to ride in any environment with peace of mind. And I was really proud that we were able to present the CBR1000RR as the most stable super sport bike in the world at high speeds and in the rain, and that riders could ride it with such peace of mind.