Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128314
r?=-=O:-:O=-4:-S=-u-z-:uk --=G:-:S=-=-X:-:-R-=7.=-=S=-=O--.-:j : = (Left ) A m ix of analog and LCD gauges pra· vides tons of information in addition to an adjustable shift light. (Below) The 750 has a new frame with a combination of cast steering he a d and swingarm p la te ections and extruded spars. through the same corner. That's the difference between a 500cc World Champion and a word hack. The crankshaft is un changed , and the rods are only slightly modified for the increased rev limit. One feature that was added to the crankcase is that four 35mm ventilation holes have been added between the cylinders to help reduce pump ing losses when the piston is moving from TDC (to p dead center) to BDC (botto m dead center). Th is has increased torque output by 2 percent at the top of the rev range . The fuel-injection system and the airbox have both been revised for 2004 . The throttle bodies are of a lighter and simpler design . The new system features twin '12m,!, two-barrel throttle bodies instead of four individual units. The th roats on each tw o- barre l body are posit ioned 5mm closer toget her, but the spacing between the two separate units is still 80m m on ce nte r. This reduces the entire bank's assembl ed width by 10mm. The injector nozzles are now a multihole des ign instead - - - - - - -- - - - - - - (Left) The frant end features new radialmount brakes and 300mm rators, while a new radiator resides behind the frant wheel. (Right) A lighter, mare efficient bank of 42mm throttle bodies and a new 32-bit ECM imprave the fuelinjection system's performance. L...L._...L:"""': lot of add itional heat. The so lut ion was to design a new t rapezoidalshape d radiator, w hich is 12 percent more e fficient wit ho ut increasing the frontal area of the bike. O ne thing t hat GSX-Rs are notorious for is intak e noise. Dur ing one se ssion , one of my earp ugs started to work its way out, and I was shocked by the sound the of of t he former bike's pintle -type tips. The system st ill featu res Suzuki's SDTV Throttle (Suzuki Dual Valve), w it h a servo-operated secondary 6utterlly optimizing tlie airllow into t e body. The injecto rs enter the body at a 60degree angle. The intake and exhaust ports are also changed with 2-pe rcent larger intake and 14-percent larger e xhaust ports. In an effort to reduce the bike's physical dimensions, the airbo x was shrunk to help reduce the size of the fuel tank's dimensions. The bike 's ECM (electro nic control modu le) now has a 32-bit processo r instead of the 16-bit computer on the old bike. This has allowed t he system to motor store eight fuel-injection maps and eight at max irpm ignit io n maps (tw o more than befo re) in its mum inches from my 256- kilobyte memory, all to provide the head as I tucked best possible throttle and engine response. in down the back I can't tell you much about the throttle straight . On the response at normal street-riding speeds, but the throttle res p'onse at track sp'e_ _ _...other hand the bikes didn't .....; _ ed =;;;;o..o:::::;;:,..:.:.;~~~~~ was flawless. The GSX-R's SRAD (Suzuki really see m th at loud from t he side of th e t rack as I Ram Air Direct) syst e m has been redesign ed , with the intakes on t he front of wa tched t he ot her gro up ride . Eithe r way t he bike sounds re ally nice at full tilt, it's the fairing moving 25mm closer together w here the pressure is the greatest, giving just t hat GSX-Rs bellow ou t mo re intake the motor that extra punch up top. how l than other bikes. Speaking of the ex haust system, it has been redesigned With the adde d performance comes a and now fea tu re s titan ium inner -co re pipes, and the o ute r mate rial is aluminum. The ex ha ust is physically large r fo r increased capacity, w hich in turn re duces backpressur e and increases performance . GSX-R tra nsmissio ns have always been excelle nt. This year the shift fork was changed to improve rigidity and improve feel. The only prob lem that I had was that it was so met imes hard to grab sixth gear at full throttle by pre loading the shifter and cra cking off t he throttle. Maybe the tranny was too new and just needed to break in a little , but almost eve ry lap I nee ded to back off the thro tt le dramatically o r use t he clutch to get sixth cleanly. The chassis is also a brand -new design, fully capable of exp loiting the motor's new capab ilities. The new twin spar fram e has a cast aluminum stee ring head section and 30 MA RCH 10,2004 • CYCLE NEWS - 40th Anniversary swingarm pivot sect ion, w hile the spars are now extruded aluminum with an inte rnal rib dividing the rails into two chambe rs for added rigidity. The frame is now 15mm narro wer between the two spars, wh ich, co mbined with the 30mm narrower fuel tank (at the rider's knees), has he lped reduce the bike's w idth significantly to help get the ride r's knees out of LIST PRICE DISPLACEMENT ENGINE TYPE $9599 749cc Liquid-cooled, fourstroke , four-cylinder BORE x STROKE 72 x 46mm COMPRESSION RATIO 12.3:1 FUEL SYSTEM ..Electro nic fuel injection IGNITION DigitaVCDI TRANSMISSION Six-speed, constant-mesh STARTING SYSTEM Electric FUEL CAPACITY 4.49 gal. WHEELBASE 1400mm (55 in.) RAKE/TRAIL 23.25'/93mm SEAT HEIGHT 32.4 in. FRONT TIRE 120/70-ZR17 REAR TIRE IBO/55-ZRI7 FRONT SUSPENSION Fully adjustable 43mm inverted fork FRONT-WHEEL TRAVEL..........4.? in. REAR SUSPENSION ....Fully adjustable 5howa piggyback shock REAR-WHEEL TRAVEL 5. 1 in. FRONT BRAKE ........Twin 300mm discs w/radial-mount 'I-piston calipers REAR BRAKE .5ingle 220mm disc w/2-piston caliper FINAL DRIVE Chain CLAIMED DRY WEIGHT 359Ibs.