The 600cc sportbikes have always been the biggest sellers for the big four Japanese manufacturers. Not only are they less expensive than the larger displacement bikes, they are also cheaper to insure, maintain and even though they don't have the same horsepower or torque as the 750cc or 1000cc bikes, they are plenty fast. During the '90s, the 600s were cranking out 85-90 horsepower and running very low 11-second quarter mile times. With top speeds in the mid-150 mph range and a 0-60 mph time of 3.2 seconds, the Honda CBR600 was the dominant bike in the middleweight class. It is estimated that Honda sold over 50,000 600cc bikes from 1987-1993, making it the most popular-and arguably the most influential-600cc sportbike ever made.
Those of you who weren't riding before the year 2000 may find it difficult to imagine there was once a time when the sight of a Honda struck fear into riders of other brands. During the years of 1991-1998, it was almost an anomaly to see anything other than the Honda CBR600F2 and F3 on top of a 600cc magazine shootout or in the winner's circle.
For example, in 1991, Honda rider Miguel Duhamel (on board the new F2) won seven of nine races, completely dominating the AMA 600cc Supersport championship; Honda F2 riders won the other two races as well. If you wanted to win races in this era you needed to ride a Honda or else your chances weren't all that good.
The F2 was announced in late 1990 at $4998 and it promised to be a worthy follow-up to the original Honda Hurricane that debuted in 1987. The CBR600F2 had a liquid-cooled DOHC engine with a 65mm x 45.2mm bore and stroke that was even more over-square than the original at 63 x 48mm. The cam chain was moved to the right end of the crank to eliminate one crank journal, and compression was bumped up from 11.3:1 to 11.6:1. The new bike also featured 34mm flatslide CV carbs vs. the older model's 32mm round-slide units. With lighter pistons, crank and con rods, it was able to achieve a 500-rpm bump in the rev-limit to 13,000 rpm. The bike also had side mounted air scoops but they fed cool air under the tank and not directly into the 6.2-liter airbox.
The engine was known for making good top-end power without sacrificing the midrange, which is one of the things that made it so special. The cams were actually designed with midrange power in mind and the excellent cylinder head flow was rumored to be the secret to the top end power. The included valve angle was shrunk from 38 to 32 degrees, and a shim-under-bucket valve actuation replaced the old rocker arm assembly. This also allowed valve adjustments to jump from 5000 to 12,000-mile intervals.
Honda also fitted a smaller clutch and primary gears to the F2 that allowed the output shaft to be positioned 0.5 inches closer to the crank. In order to compensate for the smaller diameter clutch they simply added a few extra plates and mated it to a six speed tranny. Overall the new engine was 2 inches smaller and 0.6 inches narrower and 1.3 inches shorter than the old model. This change along with a shorter fuel tank allowed Honda designers to move the rider closer to the front wheel and improve handling.
The CBR-F2 and F3 front brake...
The CBR-F2 and F3 front brake setups were very efficient for their time, especially since they only used a less expensive twin-piston slide-pin caliper against competition that was already using four-piston calipers.
The forks were upsized from 37mm to 41mm and featured preload adjustments, while a new single rear shock sported preload and rebound adjustments, in addition to a new box-section swingarm. Six-spoke RC30-style wheels were 3.5 x 17 inches in front and 4.5 x 17 inches out back. The chassis was a new twin-spar design but was still made from steel, with 25 degrees of rake and 3.7 inches trail with a 55.5-inch wheelbase. Front rotors were 275mm-diameter units squeezed by twin-piston slide-pin calipers. When fully tanked up, the F2 weighed a lean 455 pounds, making it the lightest bike in its class compared to the 490-pound Kawasaki ZX-6 or the 458-pound Yamaha FZR600.