
What a rippin’ little bike this 2004 Suzuki 600 is, and it hasn’t arrived a minute too soon, either. In a class that is showcased on racetracks around the world in a “race on Sunday, sell on Monday” atmosphere, playing ‘catch up’ can have those looking for the latest and greatest drift to competitor’s showrooms, dooming sales for the local Suzuki dealer. I don’t know what the sales figures in the middleweight supersport class were for 2003, but with new (thoroughly revised in Yamaha’s case) 600cc Supersport offerings from all of the Japanese OE manufacturers, it would not be a stretch of the imagination to speculate that Suzuki did not top sales charts after the final tally was taken.
Despite being the 2002 AMA Supersport champions, the Suzuki camp was really up against it from the word go in 2003. Aaron Yates elected to concentrate on Superbike only, leaving Ben Spies and team newcomer Jamie Stauffer, to carry on with the suddenly aging GSX-R. At season’s end, the final results spoke volumes – get back to the drawing board. The engineers didn’t just sit in front of their computers and use CAD-CAM to spit out a new bike, oh no. Race teams and customers also provided volumes of feedback to assist in the effort to hoist the Suzi back to the top of the podium of your local racetrack. Let’s see what the Hammamatsu crew came up with, shall we?
First, the obvious. It is visually smaller than last year, with the fairing appearing to have been shrink-wrapped to the chassis. The fairing itself has a sharper, more angular look, replacing the rounded contours of last year. Frontal area is significantly reduced. The headlights make their home in a stacked reflector arrangement, rather than the side-by-side design of the previous models. The narrower profile of the headlights allows the air intakes of the ram air system to move closer to the center (nose) of the fairing, where air pressure is highest and has greatest effect. You could be forgiven for mistaking the smallest GSX-R for one of its larger brothers, since the familial resemblance can’t be ignored. At a distance, differences in paint schemes and the lack of the DLC coating found on the 1000’s lower fork legs are the only giveaway that the 600 is not the 1000, or the 750. Indeed, aside from engine displacement, much about the 2004 GSX-R750 is identical to the 600, so take a look at our 2004 GSX-R750 test here for some detail photos omitted from this article.
Braking up front is handled by a thoroughly revised system. The rotors shrank 20mm, down to 300mm, and are .5mm thicker, saving 40 grams of weight. They are gripped by radial mounted four-piston brake calipers, which are topped off by a radial master cylinder that more efficiently translates lever pressure to stopping power. Not even the GSX-R 1000 has the radial master cylinder. The rear brake no longer uses a link rod to hold it from spinning on the axle when you step on the brake pedal. It now uses a tongue-and-groove setup between the swingarm and caliper mounting bracket, which is simpler and saves weight.
The 600 now sports upside down forks, with the lower tubes measuring 43mm in diameter, and is adjustable in all the usual ways. The traditional steel color of the lower tubes tells us they did not endow them with the latest super-slick coating. Out back, the shock has a 2mm thicker rod, and its overall length has been shortened 3mm.
The frame wasn’t just painted black, as it has undergone its share of changes, as well. The main frame spar is 1mm taller, has two internal ribs, and the overall width has been reduced by 15mm. These changes are intended to increase stiffness in the horizontal and vertical planes to help increase stability on the brakes and in corners.
Rake has been reduced slightly from 24 degrees, to 23.25 and trail has gone from 96mm to 93mm. Wheelbase remains 1400mm. Weight distribution is 50.5/49.5 front/rear, giving just a slight bias to the front. The swingarm has bracing now, giving it a suspiciously familiar look, like it came from the 1000, which it has.
The sub-frame is now a bolt-on piece, instead of being a non-removable item. Racers around the world rejoice!
Three-spoke, 17″ rims roll on Dunlop’s new D218s, a 120/70 front and 180/55 rear. They worked well during our street test, providing excellent traction and feedback from word go.
Now to the heart of the bike, the 599cc four-cylinder minister of high velocity. The engine has been the subject of much scrutiny and revision, which has yielded a 4% gain in power. Suzuki claims 118hp at 13,000 rpms, with torque topping 51.4 pounds/feet at 10,800 rpm (both measured at the crank).
Reciprocating weight has been reduced throughout the engine. Valves are made of titanium with smaller buckets riding on top. This allows a lighter spring rate to control the valve opening and closing, which reduces pressure of the bucket against the cam, reducing frictional losses. Included valve angle is down 6 degrees, to 22. A straighter intake tract combines with the narrower valve angle to make a smaller combustion chamber, which in turn bumps the compression ratio from 12.2:1 to 12.5:1.
Forged pistons have shorter skirts, and overall have lost 18 grams apiece. Chrome-moly steel connecting rods are 10 grams lighter each, and slightly shorter as well. The main journals of the crankshaft have been reduced from 32mm to 30mm, slightly reducing weight, and frictional losses. Ventilation holes between the cylinders reduce pumping losses, as well. All of these changes combine to create an engine that revs more freely – much more freely – and 1,350 rpm higher, to 15,500 rpms.
To help keep at bay the extra heat that the increased power brings, the radiator and water pump have been beefed up. The transmission has benefited from a selection of closer gear ratios, and massaged the rest of the transmission bits to improve shifting.
Feeding the engine its air and fuel diet, the dual throttle valve system now features lighter weight throttle bodies, holding multi-hole injectors that better atomize the fuel spray. A 32-bit processor has replaced the 16-bit processor, making fueling and ignition more accurate, which also has the pleasant effect of reducing emissions.
So what’s it like to ride? That’s the really good part. The new model has lost and gained in all the right ways, especially the engine performance. Suzuki, especially of late, has demonstrated a knack for making their engines’ powerbands extremely flexible. This engine makes very good power from 5000 rpm (arguably from 4500) all the way to redline. This range, particularly at the lower end, is really not par for the middleweight course. Only a 36cc displacement bump for the Kawasaki keeps the Suzuki from being the class torque king. Its free-revving nature means getting the revs out of the basement (sub-4000 rpm) happens almost without thought.
Once into the middle third of the rev range, the engine is making good torque and horsepower, which leaves you with a selection of a couple of gears for a given situation. On the street, the 5000 – 10000 rpm range is all that’s needed to make rapid progress. All the while, the engine is making next to no vibration, but is making wonderful sounds through the airbox, especially on full throttle acceleration. In the neighborhood of 7200 rpm, the airbox develops a resonance that makes the gas tank hum with vibration.

Fuel injection is nigh on perfect. The light throttle action makes unintended speed adjustments more likely the bumpier a road is, but ultimately aids in reducing rider fatigue, whether on a long ride, at a track day, or during a race. After riding other motorcycles with a heavy throttle pull, the light throttle action takes a small adjustment period.
Braking action on our test unit was very good, but to be quite honest, we weren’t over the moon about it. Initial bite and overall power wasn’t what we thought it should be, given the caliber of the new hardware in place, and they certainly weren’t in the same league as the fierce brake setup we sampled on the ’03 GSX-R1000. We’ve heard other journalists rave about them, so we expected better. Perhaps, we were unlucky recipients of a test unit with cooked brake pads. The rear brake performed without drama or flair. Now, about the suspension.
After much fiddling (many small changes) with preload and damping settings (there were some interesting adjustments dialed in), we achieved a good front to rear balance. The damping has a highly refined and quality feel to it. The front springs were a bit on the soft side, though, as we had only 3mm of adjustment left once we settled on the settings. I weigh in around 176 lbs. in street clothes.
The suspension did a good job of absorbing the bigger hits while remaining compliant enough to mostly erase the small, choppy stuff. Inevitably, some get past the excellent suspenders. The ones that sneak through are reduced to the merest bump.
The chassis and suspension combine to make cornering a delight. Accurate, light steering that also gives a planted feeling gives the rider loads of confidence. On a favorite local road, one that is fairly tight, rather gnarly and features elevation changes, the GSX-R600 is in its element. At more elevated speeds, the bike remains planted, but willing to change directions with minimal effort and no drama.

Available in Yellow, Also.
On open and flowing roads, the Suzi exhibited stable and reassuring characteristics that kept the rider from feeling he had overdone things. The steering damper undoubtedly played a part in keeping the bike pointed in the right direction when the pace heated up, but managed to remain largely unnoticed while operating in the urban environment.
Ergonomics are, as expected, different from the ’03 model. The gas tank is both shorter, and over an inch narrower, reducing capacity by one liter. The bars are a shorter reach, the seat is 5mm lower and the pegs are 10mm higher, making for a more cramped fit for taller riders. The higher footpeg position, combined with a 10mm narrower overall width at their tips, give an additional degree of lean angle.
On longer distances, the seat-to-peg distance became noticeably uncomfortable, and only the excellent seat kept the legroom issue from getting out of hand. If I were to buy one of these, or the 750 (they are physically almost identical), a set of rearsets would be on the purchase order to lower the footpegs, or foam would be added to the seat. Wind protection is about what you’d expect from the middle-weight class, that is, minimal.

Instrumentation is clear, concise and does not make the rider search for the necessary information. The large, analog tachometer prominently displays engine speed, while the digital readout provides road speed in easy to see numbers. Other information about the usual things is there, as well. On the left handlebar pod, you’ll find a switch to activate 4-way flashers.
We really like this bike. The only fly in the ointment for me was the reduced seat-to-peg distance. Outside of this, the new GSX-R600 is an outstanding bike. Handling is on par with the train-stable Honda 600RR, and the engine easily out-torques all but the 636 Kawasaki. I’ll give Suzuki the benefit of the doubt about the brakes, as they have equaled or bested all comers in other tests. U.S. MSRP for the 2004 Suzuki GSX-R600 is $8,099. Visit Suzuki’s web site for additional detils and specifications.
