|
By the Motorcycle Online Staff Las Vegas, NV, December 20, 2000 -- With Yamaha's track-honed R6 and Suzuki's equally sharp GSX-R600 garnering the majority of media attention, it's a shame when a great all-'rounder like Honda's newest CBR600, the F4i, gets left out of the spotlight. It doesn't deserve to, really. And after getting to spend the better part of a crisp winter day on Las Vegas' infield racetrack, we are even more confuzzled as to why this bike doesn't get the love it truly deserves. As Honda's Gary Christopher was quick to point out, no other market segment has driven sportbike sales - up 21% this year - like the 600 sector. Both he and Honda's Peter TerHorst acknowledge that the F4i is still not a race-replica, but more of a "supersport for the street." To stave off the competition, however, they point out how the new model is "more of a track machine" than the previous versions. Doug Toland and his group of technicians addressed the main complaints of consumers and then went a step further by fuel injecting the 599 cc inline four to take advantage of a few other mods.
The new subframe raises the seat by five milimeters and, with the new two-piece seat, allows more storage room in the rear compartment. Internally there was a big effort to try to make shifting smoother by cutting the gears with different angles and clearances than on the previous version. There's also a shorter sixth gear as well as a larger rear sprocket (now a 46 tooth) for more acceleration in top cog. To make sure that the top speed remains the same as last year, the rev limit was increased by 700 rpm. These extra rpm come from a few internal changes that also allow the motor, claims Honda, to rev quicker than before. To keep things cool at the accelerated rev ceiling, the oiling holes in the camshafts have been enlarged by 0.5 mm (to 2.5 mm) and piston ring friction has been decreased as well. Spring pressure on the intake and exhaust valves has been increased to avoid dreaded valve float. Also, there are now two valve springs (inner and outer) on the intake side instead of the single item that resides on the exhaust side. The camshaft sprocket is lighter this year, as well, to keep things spinning freely.
The end result of that squabble is, like the rest of the bike, a compromise between track performance and on-road goodness. The new F4i has a tank that's one liter larger than the old version and it has an airbox that grew by two liters, to fifteen. Resonators were employed to keep noise levels down and airflow up, keeping the decibel people appeased. The injectors that make up the i in F4i reside one per cylinder and work with 38 mm throttle bodies. The injectors have four nozzles each. They provide not only more efficient metering of the all-important fuel-air mixture, they also allow for a more efficient burn (the California model meets CARB 2004 emissions standards through the use of a catalyzer that drops two peak horsepower), and the choke lever has gone the way of the the kick starter. All these internal mods add up to a claimed five horsepower increase over the previous version. The new horsepower is contained within a chassis that sports ia five millimeter shorter wheelbase with a 5.9-percent increase in overall rigidity. Unsprung weight has also been reduced quite a bit due to the shaving of a few hundred grams off of key components.
Always a concern in a class that puts as much emphasis on power-to-weight ratios as it does on handling characteristics, Honda's engineers managed to shave a few pounds while increasing the rigidity and maintaining the sort of balance that has made Honda's CBR600 one of the easiest-to-ride bikes in any class. Now there's additional bracing on the steering head for "more response, better feedback and feel" from the front end. The suspension has also been tweaked with less high-speed damping and a bit more low-speed damping for improved feedback and compliance at elevated velocities. Starting out the day on Michelin's excellent Pilot Sport tires, we re-familiarized ourselves with Vegas' track layout following Jeff Haney, past factory Honda racer and third place Daytona 200 finisher who is also the lead instructor at Freddie Spencer's riding school. His lines got us back up to speed as we noticed that the newest CBR iteration retained something that has long been a staple of this particular Honda line: It's just about the easiest supersport bike to ride fast, on the street or on the race track. With tires warmed up and adrenalin flowing, the pace increased and the Moto Journalist GP, er, testing, got underway.
There's not much more important than good chassis feedback when it comes to maintaining corner speed and setting up the all-important drive down the next straight. This newest Honda's chassis changes allow a great deal of feedback to come through the bars and footpegs thanks to the strengthened head stock, says Honda. The footpegs touch down relatively soon, but the chassis never becomes upset and nothing hard drags unless you have a single-digit AMA professional racing number... or fall off. Going deep into the corners, trail-braking off of the banking, front end feel was, again, very good. The only time anything unsettling occured was the occasional front end chatter that some riders noticed here. It never completely went away, even after fitting Michelin Pilot Race radials for the afternoon sessions. Might have been a bit of fork flex, but it never got to a point where it was much of a concern. It was only a minor nuisance for some. The only real concern was regarding the front brakes, particularly slowing down from top speed while still on the banking. After only a few hard laps, the brake lever would work its way back into the fingers that remained on the grip. Honda's engineers swapped pads on our test bike and sent us back out, only to have a similar situation occur after another handful of laps.
The motor is very easy to use and get comfortable with almost immediately. There's a nice, broad spread of power that starts pulling hard right into redline. The new motor definitely feels more free-revving than the old unit. The new shift light on the tach is also a cool feature, though it would have to be brighter to be of much use in direct sunlight. Gun-shy due to some fuel-injected offerings from manufacturers with glitchy throttle response as standard equipment, we were pleased to find that Doug Toland and his group of technicians did a nice job with the mapping on the Honda. Through a long, tight right-hander that doubles back on itself, the fastest line through is to drift out mid-corner, then ease off the throttle to pinch the bike back down, getting it squared up for the drive out onto the short chute before the next right-hand kink. At the moment that you ease out of the throttle and feather it on as you roll the bike down to the apex, a glitch could spell certain disaster. Thankfully, this never became an issue.
Honda seems to have done the right thing by taking a good package and making it a little sharper for aggressive racetrack use while maintaining its user-friendliness. It may not be the supersport scalpel that the Suzuki and Yamaha 600s are, but it may surpass last year's shootout winner - the Kawasaki ZX-6R - in terms of all-around goodness. And, as far as we're concerned, having a sharp all-around bike is exactly what we want and need. |