Six Fix: 2001-2003 Suzuki GSX-R600 test

It's a common occurrence these days for manufacturers to build various models using some of the same components. Basic engine and frame designs are often used on multiple machines to keep costs down and profits up by creating another bike from the parts bin, rather than fabricating expensive, all-new tooling for just one motorcycle. It's a fairly cost-effective way to do business-as long as the bike's performance isn't compromised by the one-size-fits-all philosophy.

Suzuki is one manufacturer that has used this technique to great effect with its previous GSX-R600. The '97 GSX-R600 utilized much of the '96 GSX-R750's basic components in its design to out-handle the competition, without paying any severe weight or bulk penalties in the process.

The competition has quickly caught up with and surpassed the previous generation GSX-R600 since that time, however. So, Suzuki once again took its latest 750 platform-not a bad place to start-and revised various pieces to create an all-new GSX-R600. But can the same modular philosophy succeed a second time around?

After spending some time flogging the newest GSX-R around the street and track, we can confidently say this: the competition is in trouble-once again.
Park the 600 and 750 alongside each another, and it's difficult, at first glance, to tell them apart. The fairings are virtually identical, and if it wasn't for the 600's conventional 45mm fork up front and non-braced swingarm out back, you'd be hard pressed to identify which is which. Delve into the inner workings of the new 600, and you will find the similarities continue. The aluminum twin-spar frame structure and lower engine cases are virtually identical, and the 600 uses the same type of dual-butterfly-valve fuel-injection system found on the 750.

Ah yes, fuel injection. We've seen the Japanese factories use EFI on their bigger machines for some time now, but the GSX-R600 is one of two (Honda's new CBR600F4i being the other) 600s introduced this year that utilizes the high-tech induction system. While Triumph's TT600 was the first middleweight to use EFI, it suffered from a few glitches in the lower rpm that made us wonder if fuel injection can work on smaller-bore machines.

One benefit of fuel injection is easy cold-morning starts. As on the 750, a choke/fast idle lever on the left clip-on assists in getting the Suzuki's motor up to operating temperature quickly. Once in the saddle, you realize the GSX-R family similarities extend to the ergos and cockpit appearance too. The new GSX-R has a rather tall seat height, which keeps the legroom from being cramped due to the fairly high-set footpegs, while the reach to the clip-ons is spacious without overly extending your torso.

Getting under way from a stop requires more rpm than usual since there isn't a whole lot of torque down low, and the motor revs a bit sluggishly below 4500 rpm. Carburetion at low rpm is flawless, however; the lethargic throttle response is more a product of the highly oversquare engine (67.0 x 42.5mm bore/stroke) breathing through the comparatively huge throttle bores (41mm tapering down to 38mm throttle plates). Acceleration through the lower gears is brisk enough, but you need to be above 7000 rpm before the midrange power really starts to kick in.

Out on the highway, the windscreen provides adequate protection from the elements, although the mirrors have sacrificed function for style compared to the previous GSX-R600; they provide more of an elbow view than we'd prefer. The motor is silky-smooth for the most part, but a slight tingle comes through the pegs at 70 mph. Transmission action is less notchy than on our 750 test unit, yet it still requires a positive movement from your foot. Some liked it, while others would prefer a tad less effort at the shifter. The reach to the bars proved a bane to one tester during long trips, focusing a bit too much weight on his wrists.

The GSX-R600's rear shock works well, but we'd prefer that Suzuki provide a spring preload adjustment spanner in the toolkit. The preload collar is very thin, and getting at it is a pain.

Once into the canyons, however, all thoughts of creature comforts are long forgotten. The new GSX-R's revised chassis and motor come to life in cornering mode, and the harder you ride them, the better they respond.

The 600's suspension action is reminiscent of the 750: a fairly plush feel through the initial portion of the stroke, while still keeping the chassis under control toward the bottom half of travel. Most bumps were absorbed with little fanfare, especially at higher speeds. We had to crank-in more preload in the rear than we thought was necessary at first, to keep the bike from squatting excessively under acceleration. We found out why after a closer examination of the rear suspension; the linkage has a more linear progression curve than the previous GSX-R600, which allows more of the travel to be used for a given bump (check out Art & Science on page 76). It's obvious that Suzuki has biased the new 600 toward serious back-road/racetrack use.

Steering habits were quick, yet precise, although a bit of effort was required to initiate quick-flick turn-ins, as well as keeping the bike on-line in tighter corners. We'd guess that some of this is attributable to the non-adjustable steering damper now fitted stock to calm any high-speed chassis distractions. Regardless, the GSX-R feels very flickable in side-to-side transitions (even though it isn't as much of a featherweight as predicted-it scaled in at 423 pounds wet, only two pounds less than the Yamaha R6). And the bike tracks straight and true through the gnarliest, fastest curves you can throw at it.

The 600 features the same type fuel-injection system as the GSX-R750, utilizing secondary throttle plates controlled by the engine's ECU. The motor turning those throttle plates is now attached directly to the fuel injection body, vs. the remote cable actuation used on the 750.

And you will be running into those curves pretty fast, courtesy of the all-new, 599cc, four-cylinder powerplant. Midrange power is vastly improved over the previous GSX-R, with decent steam on tap from 8000 rpm on up. Gone are the days of keeping the old engine wailing above 10,000 rpm to access any semblance of rapid acceleration off the corners. With the new engine, there's another slight jump in power at 9500 rpm, followed by yet another at 11,500 rpm as the fuel-injected motor screams (with probably the most aggressive stock exhaust note in the class) to its 100.5 horsepower peak at 13,000 rpm-a new record for a Sport Rider production 600 test bike. This thing just flat gets with the program.

The new motor is even more of a willing revver than the previous version, making the task of accessing that top-end power easier. Interestingly, the new GSX-R has taller gearbox ratios than the previous version, and the first three seem spaced farther apart. The fact that this motor isn't exactly a torque monster, yet was able to pull those gears at the dragstrip to the tune of a 10.80-second at 125.48 mph run speaks volumes about its strength. The little Gixxer also impressed at our top speed test site, running 157 mph past the radar gun. (We guess the bike will go even faster, but since we were headed to the track, we had fitted Metzeler Rennsport tires-which are slightly taller than the stock Dunlop Sportmax D207s, thus raising the gearing slightly.)

The GSX-R600's cylinder head is totally new, featuring a flatter included valve angle (28 degrees vs. 30 degrees) that provides the usual benefits: a more compact combustion chamber, straighter intake ports, and a smaller cylinder head size overall. The intake valves are larger (27.2mm vs. 26.5mm); for less reciprocating weight, both intake and exhaust valves utilize thinner stems, with lighter, smaller, single valve springs replacing the dual springs used previously.

Slowing all that velocity are redesigned four-piston calipers clamping on the same 320mm discs up front. The new brakes are worlds better than the previous wooden-feeling GSX-R binders; their overall response, power and feel are vastly superior, and have become our new favorites on a 600cc production bike. Although the calipers have been changed, we'd attribute the improved braking performance to a new pad material. After some hard racetrack miles, we noticed that the discs' swept area was more discolored than usual, with some high spots appearing on the surface.

Oh right, the racetrack. With their continuing contingency racing program, it's clear Suzuki is trying to emphasize the outright performance aspect of the GSX-R. And it's apparent once you venture out onto racetrack tarmac that the Suzuki is clearly in its element.

When we tested in the canyons, it was evident that the faster we went, the better the GSX-R behaved. Not that its manners in the slower corners were poor, mind you; it's just that the Suzuki preferred a chance to stretch its legs and show you what it was really capable of. After slipping on some Metzeler Rennsport DOT racing tires, we segued to the Streets of Willow circuit for some all-out pavement scratching.

Since the lack of swingarm bracing precludes the mounting of a rear fender, Suzuki installed this guard to keep gunk from building up on the rear shock.

The Metzeler's taller profile raised the rear about 6mm, which, combined with the front tire's more rounded profile compared to the stock Dunlop Sportmax D207, alleviated much of the effort needed to hold a line in slower corners, and provided more neutral steering while on the brakes. (It also fostered a penchant for slightly falling in near max lean, however.) The GSX-R simply railed through the fast bumpy stuff, as the well-sorted suspension kept things well-managed in areas where other bikes would be getting a bit unruly. Excellent front end feedback promoted blazing corner entry speeds, and ground clearance was never a factor, with only the pegs barely touching down.

The new GSX-R600's rear suspension linkage has a much more linear progression curve than the previous generation model, which results in better bump absorption at higher speeds. It's pretty obvious that Suzuki is aiming for the new 600 to dominate at the racetrack in 2001.

Letting the motor really unwind up to its stratospheric 14,500 rpm redline verified its class-leading horsepower, and its improved midrange helped tremendously through the Street's tighter sections. Where the previous GSX-R would force you to downshift in order to get good acceleration, the new 600 allows you to pull a taller gear and carry corner speed and momentum, translating into higher straight speeds. The brakes were superb, slowing the Suzuki with excellent feel and power, and virtually zero fade.

It's pretty amazing how far middleweight performance has progressed in the past decade-hell, even in the last few years. We now have 600s surpassing the 100-horsepower mark, weighing less than 400 pounds dry and possessing top speeds that smoke the best 750s of only five years ago. The Suzuki GSX-R600's incredible performance is easily a match for the best in the class, and what's even more amazing is that its overall design is closely based on its 750 brother. Suzuki had a good platform in the 2000 GSX-R750, so why not expand on it? Sometimes the phrase, "a chip off the ol' block" really isn't a cliche.

We can see the mother of all middleweight sportbike battles looming over the horizon....

Suggested suspension settings
Performance numbers
Dyno charts
Weights and measurements

sr opinions
I've been worrying about the new GSX-R600 ever since I rode the 750 version last year. That bike was such an improvement over the old 750, I was concerned my own Gixxer 600 racebike would be practically worthless with the introduction of the new model. It's been sitting forlornly in the garage lately, and now that I've ridden the 2001, I have mixed feelings about keeping mine.
The new 600 has the motor that the old version desperately needed, and that puts it right in the thick of things at the top of the class. However, being based on the 750 chassis leaves it-especially when compared to the R6-a bit on the large side, and I'm not sure that the parts-sharing philosophy will work in the 600 class anymore. Instead of being the revelation that the 1997 600 was, the 2001 bike feels like...well, the 750 with 20 less horsepower.
Still, the GSX-R is a great platform for a Supersport bike, and undoubtedly will collect its share of trophies. I'm just trying to convince myself that old faithful doesn't need to be replaced. Maybe it's time to face reality: for sale, 1997 GSX-R600.... -A.T.

When I first rode the Gixxer on the street, I wasn't terribly impressed. Although I loved the sound of the new, meatier engine and the romping midrange power that came with it, the bike steered heavy and didn't offer the variety of lines entering corners that I found so irresistible in the R6 during last issue's BOTY test. As I spent more time in the saddle, I realized the GSX-R600 worked better the harder I pushed it. However, it stood up in a big way during midcorner braking maneuvers-not exactly what I wanted in the unpredictable street environment. Ultimately, I grew to like the 600, although I'd take out some of the suspension's racetrack stiffness for street use.
Riding the GSX-R600 at the Streets with Metzelers was a revelation! The rounder profile of the tires allowed me to exploit the bike's spectacular brakes. Trailing the binders into corners caused no ill effects on the turn-in. The Suzook's stability inspired my confidence. Yeah, turning or altering lines required a bit of effort, but charging out of the corners or accelerating over pavement irregularities didn't upset the 600 at all. I can't wait to get this puppy on the big track.
I'm counting the days until our 600 comparison. -E.B.

GSX-R vs. R6
Measuring up the new Suzuki against last year's champ

Before we go any further, remember that the R6 we used here was the 2000 model, not the 2001 model, which will have some updates. We only wanted to see how the new GSX-R600 compares to last year's class champ; one that stood head-and-shoulders above the competition.

The first major difference is apparent the moment you sit on them: the R6 is far narrower at the knees, and feels almost like a bicycle in comparison to the Suzuki. Its seating position is more upright, with a much shorter reach to the bars and a tad more legroom. The GSX-R's fairing provides much more wind protection than the R6's relatively skimpy windscreen.

Out on the twisty pavement, the R6 is far more nimble in the tighter sections, allowing you to pick and choose your intended cornering line with little effort. The GSX-R requires more muscle to initiate a turn or change lines midcorner, and prefers you use some body weight to help change direction (the steering damper probably plays a role here). We also noticed the GSX-R has far more engine braking than the Yamaha; it slows drastically when the throttle is closed compared to the R6, especially in the lower gears. This demanded more effort to run as quickly as the Yamaha in tighter sections, as it required higher entrance speed and precise throttle control. The R6 seems to be geared much shorter than the Suzuki, yet it allows you to coast into the corners far easier.

The faster sections, however, is where the GSX-R plays its hand. Its front end stays planted in situations where the R6 tends to get a little nervous, and its superior horsepower is apparent coming off the moderate-to-high-speed corners. The Suzuki is stable as a rock compared to the Yamaha; midcorner bumps are shrugged off with little notice. Plus, the GSX-R's brakes actually surpass the R6's former class-leading binders in power and feel.

It's much the same story at the racetrack. In the tighter sections, the Yamaha would scythe through without much drama. The GSX-R required a bit more effort to hustle around hairpins and tight chicanes. The R6's shorter gearing played into many of the Street's slower cornering configurations, while the Suzuki's slightly taller ratios had it a touch off the real meat of the powerband. Both bikes' decent midrange power allowed them to pull taller gears and carry momentum through some of the tighter sections. Meanwhile, in the fast stuff, the GSX-R ruled.

What did the numbers say at the end of the track session? We ran out of time to try a few chassis and suspension adjustments, but without giving up too much before we get all the 600s together...let's just say the Yamaha and Suzuki were damn close. And there was still some debating going on among the staffers as to which each would choose. So let's hurry up and get the rest of the 2001 contestants together. There's going to be one hell of a 600 melee coming up in the next few months! -K.K.

This article originally appeared in the February 2001 issue of Sport Rider