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/128306
ng the infield. The fork d excellent damping rates, gave excellent feedback from ron t end - even while trail braking into tum one. There was never a hint of chatter, allowing the front tire's adhesion to the road to be easily interpreted. In the tighter corners the chassis allowed the bike to be trail-braked deep toward the apex with the bike only standing up a limited amo unt. Dunlop pro vided an excellent co mbination of ru bber for. ou r day at th e track, including a 0 208 GP-A front and a Japanese made rear t hat 's not curren tly in production. The combination t urned out to be extremely potent and an excellent combination for the ZX-IOR. The front tire combined with the ex cellent fork gave me to ns of confidence all day with excellent grip and feedback. The rea r was even more impressive, offering excellent feel, predictab le on -throttle slides and impressive durability. The ZX- IOR, like its little brother the 6R, inco rpo rat es radial-mount ed Tokico fourpist o n caliper s up front. W hen co mbined with t he new 300mm petal discs (an industry first on an OEM sporrb lke}, which are designed fo r impro ved coo ling and are lighter t han the old ro und ver sio ns, the sto pping powe r is impre ssive. At the end of t he st raight before the infield hairpin, I ex perie nced a co uple of impre ssive 130 mph sto p- t hat Kawasaki's engineer s had was to make t he mo to r as com pact as possible, and th ey met t hat goal. The new o ne-piece cylinde r/cran kcase design, co mbined w ith the new t ri-ax is transmission and crankshaft layo ut and com pact cylinder head , make t he moto r ext remely compa ct and allowe d t he bike's center of gravity to be moved lower in the chass is. The lOR uses plenty of ultralightweight materia ls to keep the bike fro m getti ng porky. In additio n to the magnesium engine covers, a titanium exhaust syste m, which sintered aluminum valve-spring retainers and forged aluminum pisto ns all help to red uce recipro cating mass inside the engine features an aluminum canister w ith Ti inte r- t he corner, t he bike wo uld stutt er slight ly. It wasn't a big hiccup, just a little burp. I'm not sure if the pro blem is a fuel-inject ion mapping issue, or something as Simple as the throttle pulley tension being too light, making it overly sensitive, but it's definitely wo rth mentioning. The Kawasaki is going up against som e stiff comp etition in the 1000cc spo rtb ike cat egory, so the mo tor was built to impress. It's hard to say how t he bike co mpares to the per ennial powe rho use G5XR I 000 witho ut riding the m back-to-back, but the ZX-I OR has a whole lot of moto r. Th e midrange perfo rmance didn't feel quite as st ro ng as the G5X-R's, but it's hard and cont ribute to more horsepower. The ZX- IOR jettisons its old carbu reto rs in favor of a bank of fou r 43mm Mikuni t hrottle bod ies at the business end of the new fuel-injectio n syste m.The fuelinject ion system was a long time co ming and co uld still use a little refinement. In particular, exiting t he tight infield hairp in, t he throttle res po nse wasn' t quite perfect. As the thrott le was cracked o pen exiting pies as I slowed t he bike fro m 140 to 35 mph for t he first-gear corner. The co mbinatio n of th e awesome sto ppers and t he short whee lbase makes you squeeze the right lever with care. All of the significant upgrad es to th e chassis wou ldn't mean a who le lot if t he motor was a dud, but luckily that's not t he case . The lOR's new liquid-cooled moto r displaces 998ccs with 76 x 55m m bore and st ro ke dimensions and fo ur valves per cylinder. O ne of t he most impo rta nt goals Art In A FramE! The ZX- IOR's all-new flat-blackaluminum tw in-beamframe is an impressive composite structure composed of a combination of pressings and castings designed to be very light,compact and strong.Theframe's most unique feature is that the beams run over the top of the engine instead of around it, allowingthe bike to be extremely narrow.The frame's die castings are made from thinwalled 2.5mm-thick aluminum and combined with the frame 's castcross pipe, reduces the number o f pieces and the number of we lds needed to assemble the unit. The reason that the frame's beams run ove r the to p of the engine instead of the traditional route around it is to make the lOR extremely narrow - abo ut the same as a 600cc sportbike .With a little he lp from the compac t engine, the distance between the steering stem and the sw ingarm pivo t has been reduced significantly for nals, helps to keep t he lOR we ll below 400 po unds.The exhaust also features a butter fly valve in the collector to optimize flow fo r improved power deliver y and also features a catalyzer. Titanium exhaust valves, improved handling.This was done with the goal of lengthening the asymmetrical gull sw ingarm, not only improving traction but suspension action as wel l. The frame also features a central ram-air duct that passes through the frame tubes to feed the airbox , which nestles nicety in between the frame rails.There is no wasted space on the lOR. www.cyclenews.com CYCL E N EWS . JANUARY 14, 2004 51