Everyone knows it's a tough world for the major manufacturers in the sportbike market these days. Staying competitive has meant compressing the new-model development cycle (when more than just a few minor updates and a paint scheme change are made) down to every two years, and marketing demands often call for as many flashy new components as possible to enforce that "new and improved" mantra.
As the oft-acknowledged king of the literbike class for the past few years, Suzuki's GSX-R1000 has lived that tough life, enduring continuous attempts at dethronement without too much change to the basic package. But now that the two-year cycle has passed, everyone has been waiting to see what Suzuki has had up its sleeve for improvements to the big Gixxer to keep it atop the literbike heap for '07. While the basic details of those changes were released to the public late last year, the real nitty-gritty technical information-and the opportunity to experience whether those changes have actually improved the breed-came at the world press introduction recently held at Australia's famed Phillip Island Grand Prix circuit. If there was ever a track that would expose any major performance faults in a literbike, Phillip Island is the one.
So just what hath Suzuki wrought on the new GSX-R1000? And more importantly, has the company managed to improve its already formidable performance capabilities?
Let The Bike Suit The RiderSuzuki faced a quandary while developing the new GSX-R1000. The R&D; team knew the next-generation machine needed to have improved power characteristics in order to stay ahead of the competition (despite the fact that the older model already had one of the best powerbands in the class). But they were also aware that the ever-increasing output of the Suzuki's amazing literbike engine meant the pool of riders able to come anywhere near exploiting that performance got even smaller at the same time. While one Suzuki test rider believed in softening up the initial engine response to throttle movement, another saw crisp but linear response as the proper way to keep the power as friendly and accessible as possible.
This led to the development of the Suzuki Drive Mode Selector (S-DMS), a system allowing the rider to select from three different engine maps via a two-way switch on the right handlebar. Because the secondary throttle plates in the EFI throttle bodies are already controlled by the ECU, Suzuki engineers were able to manipulate the engine power by regulating the movement of the plates relative to the primary throttle-plate movement controlled by the rider, in addition to changing fuel and ignition curves. According to Suzuki, the intent was to provide "settings designed primarily for circuit riding that offer differing throttle response and power characteristics for various circuit layout sections, pavement surface and traction conditions." The A map is basically the max power setting, providing "sharp response at all throttle-opening ranges." The B mode offers "softer response than A mode up to the middle throttle-opening ranges," while C mode gives "soft throttle response at all throttle-opening ranges by reducing engine power."
Of course, all this power-control technology would be a moot point if the engine didn't have more power. However, Suzuki didn't want to stray too far from the formula that has been so successful since the GSX-R1000's inception, so it kept the basic architecture of the 999cc four-cylinder engine intact, including the 73.4x59mm bore and stroke configuration, which so far has provided an excellent balance between top-end power and midrange torque. All the basic engine dimensions remain the same, including the cylinder pitch, mainshaft spacing (crankshaft to transmission, input/ output shaft) and cylinder angle.
The biggest changes were reserved for the cylinder head. Both intake and exhaust port shapes were reworked, with the intake ports enlarged by 10 percent and the exhaust ports opened up by 20 percent. The titanium exhaust valves themselves are 2mm larger (up to 26mm), while the 30mm titanium intake valves remain unchanged. Combustion chamber shape and compression ratio are unchanged, although the spark plugs are now iridium-tipped for more consistent spark under high-stress conditions.
Both intake and exhaust camshafts underwent some modification, with the exhaust cam getting slightly more lift than the previous generation (8.9 versus 8.3mm); intake valve lift remains identical to before. Interestingly, the '07 cam timing has slightly less overlap and is advanced a bit compared with the older-model GSX-R; while the intake cam duration is slightly less (290 versus 295 degrees), the exhaust cam duration is longer (280 versus 275 degrees). This seems like it would be more beneficial for low-end efficiency (read: emissions) than anything else, but Suzuki engineers also tweaked other internal components that both raise the power peak by 1000 rpm and give a 250-rpm-higher redline, resulting in a claimed four-percent top-end power increase.
Fuel-injection throttle bodies remain the same size at 44mm, with Suzuki's SDTV (Suzuki Dual Throttle Valve) system smoothing off-idle throttle response. The new 12-hole injectors that replace the old four-hole units not only produce a finer spray of fuel for improved combustion, but the complete components themselves are much smaller, allowing the primary injectors to be positioned at a steeper, 30-degree angle, where they can spray more directly down the intake ports for even better combustion. A new ISC (Idle Speed Control) system incorporated into the throttle bodies automatically adjusts intake airflow volume with a bypass valve under various conditions so that the engine quickly settles into its normal idle speed; the system also runs the fast idle during cold starts.
Getting the engine to spin higher rpm without lightening the reciprocating parts required some engineering tweaks to reduce mechanical losses. One way is to reduce pumping losses (as each piston moves downward, it creates backpressure in the crankcase), so the crankcase windows between each cylinder cavity were enlarged by 9mm, with each hole now measuring 48mm in diameter to allow improved crankcase ventilation. The secondary counterbalancer driven off the front of the crankshaft to help reduce vibration remains.
Exhaust gases are handled by a combination titanium/stainless steel underengine system similar to that of the GSX-R750/600. The four titanium header pipes feed into two collectors, which then lead into a stainless steel chamber underneath the rear of the engine that contains Suzuki's SET (Suzuki Exhaust Tuning) valve and larger catalyzer. (The chamber's complicated shape and the heat retained by the catalyzer prevented titanium from being used in this part of the system.) To improve exhaust flow, the new GSX-R features dual muffler canisters instead of the usual single unit, with one exiting on each side.
Down in the transmission cavity, the gear ratios are identical to the previous generation GSX-R's, but the final drive is shortened a bit by the fitment of a one-tooth-larger rear sprocket. The clutch is now hydraulically operated (replacing the previous cable-activated unit), and the back-torque slipper-clutch mechanism has been upgraded with modified ramps and four reaction springs instead of three, for smoother operation. Although Suzuki claims the hydraulic actuation-which definitely adds weight over a conventional cable-operated unit-was used for its self-adjustment advantage, we're thinking it's due to stiffer springs fitted to the clutch basket in order to hold the engine's increased power. A hydraulic clutch doesn't need the freeplay necessary in a cable-operated clutch to allow for plate expansion; that extra lever travel can be used to increase the leverage ratio, which allows stiffer springs to be utilized with the same lever effort.
The GSX-R's trademark twin-spar aluminum chassis received a thorough overhaul as well. Utilizing the now-prevalent precision die-casting technology that allows the manufacture of intricate components with less welding, more precise thickness and lighter weight, the frame is composed of five main cast aluminum-alloy sections, instead of the seven pieces that made up the old unit. The reduced number of parts and welded connections cuts even more weight while allowing Suzuki engineers to precisely tailor the amount of flex necessary for good cornering feel.
The new swingarm follows a similar pattern. Instead of the previous stamped aluminum sheets welded to a cast pivot section, the new swingarm is built from three separate aluminum die-castings. As with the new frame, this made it possible to optimize the thickness of each swingarm section, reduce the number of component parts and welding without reducing rigidity, and even cut weight by 200 grams. The overall rear axle position was moved back by 10mm, stretching the wheelbase slightly from 55.3 to 55.7 inches.
Both the 43mm KYB inverted cartridge fork and rear shock now feature high- and low-speed compression damping adjustment in addition to the usual rebound and spring preload adjustment, allowing much more precise dial-in for a particular rider or riding situation. Suspension travel in the front fork has also been increased 5mm, to 125mm, and the diameter of the upper fork tube is now 2mm larger at the lower triple-clamp area for increased rigidity. While rake angle remains the same at 23.8 degrees, the triple-clamp offset has been reduced by 2mm for an increase in trail by the same amount to 98mm. The rear shock linkage has been redesigned, with the link now pivoting directly off the swingarm instead of the frame to allow more room to accommodate the underengine exhaust chamber.
A telescoping steering damper is mounted crosswise in front of the steering head as before, but with a twist: A solenoid valve operated by the ECU changes the damping rate by moving a tapered needle inside the main damping circuit. This allows for less damping at slow speeds for lighter steering, and more damping force at higher speeds, when it's needed most.
Although the front-brake discs are the same diameter and thickness as before, the disc carriers utilize 10 floating buttons instead of eight, which permits the carriers to be thinner, resulting in a 70-gram weight reduction on each side. And the same aluminum alloy rims now come shod with Bridgestone's latest variant of the new OEM-spec-only BT015 radials.
Unfortunately, all these improvements come at a price: The new GSX-R1000's claimed dry weight is 13 pounds heavier than its predecessor's. Suzuki engineers acknowledged after some prodding that the primary culprit for the added weight is the ever-tightening emissions regulation in Europe and the U.S. The larger and bulkier catalyzer necessary to adequately clean up the exhaust gases was largely responsible for the design of the underengine chamber exhaust system to house it (as well as the chamber's heavier stainless steel construction). The dual mufflers essential to maintain exhaust flow while keeping noise levels in check also added a few pounds.
So Does It All Work?
First impressions of the new GSX-R as we ran a few warm-up laps at Phillip Island were that the previous generation's aggressive but sane ergos remain, albeit with a very slight change to bar angle. Dash layout is basically identical to last year, save for the S-DMS display on the right side of the analog tachometer, and fairing protection and vibration levels remain the same, i.e., very good. We rode with the adjustable footpeg brackets (carried over from the latest GSX-R600/750) set in the highest position, which afforded excellent ground clearance without feeling too cramped.
Thankfully, despite the trend toward top-heavy powerbands as power outputs steadily grow, the GSX-R1000's trademark superb low-midrange acceleration has survived intact for the most part. Only a very slight weakness between 5000 and 8000 rpm compared with the previous-generation GSX-R is perceptible, and on the track it was basically a nonissue. As always, off-idle throttle response is smooth at any rpm, allowing early throttle application on corner exits, and overall acceleration response to throttle input is very linear throughout the powerband.
Once the rpm near the 9500 mark, however, the new GSX-R quickly begins to exhibit a stronger top-end pull than the previous version. While the old model was surely no slouch, the '07 Gixxer has a definite advantage on top end, accelerating harder and longer toward the indicated 13,750-rpm redline with a slightly better overrev capability that can negate an upshift if need be. Where the old GSX-R began to sign off a little past 12,000 rpm, the new version continues to pull strongly all the way past 13,000 rpm with ease.
And what of the S-DMS? The aforementioned subjective impressions were obviously made while running on the full-power A map. When we tried the B map for one session, we found-in the dry, good tire/pavement grip conditions we had at Phillip Island at least-that the softer engine response was actually a bit annoying. For our tastes, the engine response was softened up a little too much, and all it did was seemingly hurt the drive off corners, because grabbing more throttle didn't help offset the initial soft response. In different conditions-say, on the street with less grip and lower overall speeds-the softer response might be more help, and we'll reserve final judgment until we get a test unit in our hands here in the States.
The C map, which was originally stated as a "wet conditions" power mode, was basically useless at Phillip Island. While the B map still allows access to full power once past half throttle and a certain rpm, the C map is detuned all across the board, and in a major way. One Suzuki engineer stated that the C map drops overall power by up to 20 percent, which would equate to almost a GSX-R750, and that's what it felt like-well, a slow-revving, heavier GSX-R750, actually. I'm not so sure it would even be that much of an aid on a wet surface, either; if you wanted to push a button and say, "Voila! I've got a GSX-R750," you'd be better off with a real 750.
We had absolutely no complaints with regard to the GSX-R's overall handling and, despite the minor increase in trail, we found the steering through fast switchbacks at Phillip Island to actually feel a bit quicker than with the old Suzuki. We were worried the electronic steering damper stiffening up at high speeds would make for high-effort steering as well, but thankfully that wasn't the case at all; steering was crisp and precise in all situations, and the front end actually wiggled slightly a few times while accelerating flat out in fourth gear over a rise in the track. We prefer the steering characteristics of the new Bridgestone BT015 rubber over the previous BT014s, with the newer 'Stones offering quicker handling, better manners while trail-braking and slightly better edge grip.
The addition of high-speed compression-damping adjustment to the suspension is a welcome aid to dialing in the handling of the big GSX-R, easing the task of smoothing out some minor handling anomalies we were experiencing out on the track. Especially with the deceleration-as well as acceleration-capabilities of the new Suzuki: Although engineers claimed there were no changes to the brakes/calipers themselves, we found the power and feel of the brakes to be slightly improved over the previous model. The '07 units have a more progressive action, requiring less lever effort for the same power, which is a good thing when you're trying to brace your body from the braking force, blip the throttle on downshifts and steer at the same time. Speaking of which, the revamped slipper clutch provided excellent insurance against sloppy downshifts, working even better and smoother than the old version, which was one of the better units to begin with.
Come On, Bring It
As difficult as it is to believe, Suzuki has upped the ante once again with the new GSX-R1000. Despite the added weight, the new GSX-R appears poised and ready to defend Suzuki's literbike-class crown against threats like Yamaha's latest R1 as well as the already capable Kawasaki ZX-10R and Honda CBR1000RR. And now that Ducati's superb new 1098 is taking direct aim at the Big Four literbikes, we have the makings of a battle the likes of which haven't been seen in years. We'll see you next issue.