Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128372
MOTOR KEY FEATURES: • Larger 40mm throttle bodies • Ultra compact 599cc motor • Compact slant-block design w/stacked gearbox • Forged pistons The motor in the R6 is one of the best all-around powerplants in the class. The 599cc short-stroke motor was already good, but Yamaha decided to make some minor tweaks to improve its overall performance. The key things that are new on the R6 are the 40mm throttle bodies, the air funnels that feed them and the ECU that controls them. So why did those same changes almost cost the Yamaha the shootout this year? Because, despite the fact that they helped to increase the bike's power output by 2.23 horsepower (106.15) and increase the torque (43.89) marginally, the throttle bodies' fuel delivery isn't as smooth as before. Yamaha has gone down this road before with the RI. On the R I, they decided to ditch the vacuum-assisted secondary throttle butterflies and go with servo-driven units on the current generation bike. This allows the bike to make more power, but at the expense of smoother pickup from a dosed throttle. To be fair, the response on the new R6 isn't too bad, but it is definitely noticeable, and more so on the street than on the track. Every one of our testers commented negatively about the fuel delivery. "The throttle response is still a bit harsh, but it didn't bother me enough on the track to knock it out of second on my list," Montano added. Others commented about the bike's lack of midrange power and torque (it had the second-worst peak torque rating), but the R6 had the third-highest peak horsepower rating (106.15), not to mention that those other two displaced 749 and 636cc, respectively, and it trounced the other two 600s in the test. Yamaha didn't make a lot of changes, but the aforementioned changes were enough to bump up the bike's power a noticeable amount. On the street, the R6 (despite the FI) still made it into the top three of most of our testers' lists, slotting it into a solid second on the street balloting. So, the consensus is that the FI isn't perfect, but it also isn't bad enough to be a major penalty. CHASSIS/HANDLING KEY FEATURES: • Fully adjustable 41 mm inverted fork w/added trail • Braced GP-style swingarm • Brembo radial-pump master cylinder • Radial-mount calipers • New 12O/7OZR17 front tire The R6 is the weapon of choice for more racers in this country than any other bike around 600cc. Just look at the results for the Daytona Supersport race: More than half of the field was R6-mounted. So what makes the R6 such a potent track weapon? 24 APRIL 6,2005 • CYCLE NEWS Handling, handling, handling. Yamaha decided that the R6 needed a new fork to remain competitive, but this mission led to a whole host of changes. The fork itself is a new, fully adjustable 4 I mm inverted unit, while the triple clamps have been redesigned as well. The front end sports new geometry figures for added stability with more trail (95mm) and less rake (24.5 degrees) than before. Additionally, Yamaha has opted for a new front-tire size for 2005, with a 120170ZRI7 (instead of the 120j60ZR17 on the previous model). One thing of note is that the new R6 is very sensitive to different tires. The bike was perfect on the new Michelin Power Race tires that we used in this shootout, but on a previous occasion, we noted that the suspension required a lot of fiddling to adjust to the new Dunlop race tires. "The R6 has made big gains in stability without any loss to its quick handling, and the new radial-mount brakes are also a big improvement," Montano said. The R6 was one of the lightest bikes in the test last year, and despite gaining two pounds, it now has the lightest wet weight in the group at 422 pounds. The number-one comment that our test riders made was how well the Yamaha turned on the track. Words such as nimble, predictable and quick were all used to describe the bike's racetrack handling. The R6 also received high marks for the quality of its suspension, both front and rear The R6 still has the best handling of the group, but a decent amount of stability has been added to the bike because of the front fork's new geometry. Although the R6 cuts through comers with amazing ease, none of us expected that the bike would tum such good lap times. The Streets of Willow requires strong acceleration in acldition to handling, and it was the lack of grunt coming off the comer that we thought would hold the bike back. However, it had just enough grunt and more than enough handling to bum off the second-fastest lap of the day (a I:26.30), just a tick behind the Ducati. On the street, the R6 received good marks across the board in the handling department. The suspension was rated high, and the chassis is more than forgiving enough to deal with the bike's Iess-than-perfect fuel delivery. The brakes on the R6 are new, with radial-mount calipers, new rotors and a new Brembo master cylinder. They require a bit more effort than the others at the lever, but power is excellent. Our only gripe would be that the span adjuster is a bit of a pain to deal with. Positives - Excellent suspenSion - Best handling bike - Lightest wet weight Negatives - Throttle Response - Notchy transmission shifting