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/127173
f Mr. Su lu had been born in th e 20t h cent u ry. ra ther th an t h e 23rd, h e'd n e ve r h a ve be come firs t officer of th e Srarsh ip En terprise. You see, Su lu was a speed junkie. No, no t th e pharmaceut ica l variety, High speed. Li ke warp factor seven. But since The Feds o ut lawed priva te land vehicles , Sulu was fo rced to seek out th e on lv other course of action ava ilabl e 1<; him - a ttending the Starshi p Flight Academy a nd learn ing to pi lot a n interga lactic cruiser. So why the n, in the la te 1980s. wo uld Su lu have bothered 10 beco me an astronau t? Do yo u kno w how m uch trai ning is required to lea rn the in trica cies of a zero-gravity e n viro n m en t, n a vi g a t ion b y the stars, a nd a tmos p he re reent ry? Wh en with a mere Ill-m inure stin t in a DM V park in g lot , he co u ld become fu lly q ua lified to o pera te 'o n e o f th e fastest vehicles o n Planet Ea rt h th e Kawasaki ZX-IO Ninj a. Which is n ot to say th at th e ZX is a ny easier to opera te, or a ny less forgiving , but to go much faster than thi s you 'd n eed four wh eel s. O r w i ngs. And a wh ol e lo t m ore money . .. In 1989, th e ZX-IO Ninja returns for a second year as th e flagship of Kawasaki 's sporting lineup. And I 16 while th e "ZX- IO" designation fi ts, recalIing scie nce ficti on class ics suc h as T H X I 138, 2001 a nd 2 112, so me how the "Ninja" family name j us t does n 't do this bik e justice. U n li ke the Big Green K's o the r spon bike offeri ngs, the ZX-I O is in a class of its ow n . "Scotty. we need more power" Down in the engine room, Kawa saki engineers based the ZX- IO's 997cc motor o n the original 1000R X Ni nja, reta ini ng the sta ndard 74 x 58m m bore a nd stroke b u t redesigning th e cylinder h ead , valve tra in a nd cran kshaft. Stra ig h ter semi-downdra ft intake pons are ha nd -po lished befo re asse m bly and lighter ind ividual roc ker ar ms repl ace the pa ired system used previousl y. A narrower 30-degree included va lve angle an d , flat-top pi stons create a more co mpact co m bus tio n ch am ber a nd boost the co m p ressio n rati o to a healthy II :\' A larger eig h t-liter a ir box feeds , a n improved version of Kawasaki 's pat ent ed high-vel ocity ca rbu re tor ind uction system throug h four sem i flat -slide 36m m Keihin co ns ta nt velocity ca rbs. Li ghter pi stons an d a lightened cra n ksha ft a nd bal ancer raise th e redline to 11 ,000 rpm - a n increase of 500 rpm. T he result o f a ll th ese cha nges is a claimed 137 horsepower at th e co u ntersha ft, a figure we would not dispu te. T he engi ne is both liquid a nd o ilcooled" with ' th e rad iator a nd o il cooler mounted between th e front frame downtubes (wh ich unbolt to facil itate engine rem o val ). Addin g coolant to th e ra d ia to r requires on ly the removal o f two screws secu ri ng a small p las tic co ver o n the righ t inside fa ir ing pa nel. "Live lo n g and prosper " All the horsepower in the world won 't do yo u a ny good if you ca n 't co n tro l it, a n d the ZX's brakes, chassis a nd suspens io n are well up to the tas k. Up fron t, d ua l full -fl o at in g 300m m di scs are grasped by two sing le-action, twin -p iston ca lipe rs (with sma ller p istons at th e leading edge), a system Kaw a saki calls Bal a nce d Actuation Caliper s (BAC). T hough th e front brak es ar e term ed full -floating, th e ac tua l a mou nt of la teral movement is minima l. Rear sto p p ing pow er is su p p lied by a so lid 250mm di sc with one floating BAC caliper m ounted under th e sw inga rm. ' Wh eels are th ree-sp ok e cas t a lu m in u m - a 3.5 x 17-inch front and a 4.5 x 18-in ch rear '- which ar e both shod with Dunlop 's low-profil e K455 radials - 120170 up from and 160/60 at the rear. Th e c hass is in corporat es two massive, extruded, dual-box-section a lu m in u m spars which wrap around th e engine as th ey m ak e their way m ore or less directl y from th e steerin g head to th e swin ga rm pivot. The result is an extrem ely rigid, yet light , structu re which Kawasaki terms an "e-bo x." A 4 1mm Kayab a telescop ic fork wi th a n integral fender -m oun ted bra ce soa ks up paveme nt irre g u la rit ies a t th e front, while a bouorn-Iink U n i-Trak featuring a si ngle Ka yab a shock performs simila r duty a t th e rear. The rear shock is adjustab le two wa ys - by vary ing a ir p ressure to det ermine spri ng rate, or by turning a fou r- p o si ti on kn ob to a d j u s t rebound dampin g . "Phasers on st un " If th e ZX-IO is a ny th ing, it's a wellro u n ded package. Unlike m any sp ort b ikes, it 's co m fonable in en viro n ments beyond a twi sty ca nyo n road. Although th e reach to th e handl ebars is long, even for taller riders, the riding position is otherwise ideal. In fact , it's well -suited to a long day 's ride - two -up touring is not out of th e question. Handling is not at alI cumbersome in sp ite of th e bike's relative largeness. Suspen sion works weII front and rear, though th e non-adjustable fork is slightly harsh on smalIer bumps. And though the rear suspension damping adjustment knob