Cycle News - Archive Issues - 1980's

Poor low-end hurts t he RM 's performance. but an excellent suspension and handling keeps the Suzuki in the ball park. Good weight distribution m ak es the Kawasaki easy to throw around . The KX makes good power off the bottom but flattens out on top. Showdown '86: Kawasaki KX125E1 VS. Suzuki RM125G VS. Honda CR125R VS. Yamaha VZ125S: Part 2 How they perform By Kit Palmer Last week we took a close-up technical look a t the four 1986 125cc mo tocrossers from J apa n: the Kawasaki KX I25El , the Suzuki RMI25G , the Honda C R 125 R a n d th e Yamaha YZ125S. The Kawasaki , Suzuki and Yamaha are all -new, with changed motors, frames a n d suspensions; th e 16 H onda is ba sica l lv refined. This week, we see ho w th ese bikes ac tua lly perform o n the track , a nd how th ey co mpa re to each o ther. Now we fin d o u t wh ich o ne is bes t! Starting th ese motorcycles is basica lly n o probl em , but th e easiest to start with th e lea st amount o f pain is the Suzu ki. The R M is th e onl vone of the fou r bikes that doesn 't sm'ash th e ri de r's [oat into th e footpeg a t th e bott om o f th e stroke . T o prevent a smashe d [oat on th e H onda, Yamaha a nd Kawa saki , the r ider must keep h is foot a bo ve th e p eg a t th e bottom o f th e st ro ke; tha t cu ts th e swing o f th e sta rte r lever a lmost in half, so it la kes a number o f qui ck jabs to get th e jo b do ne . Once o n th e track, it 's easy to tell th at the Yama ha a nd H onda have th e most power; th e biggest d ifferen ce betw een th e two is that th e H onda 's power band is m uch smoot he r a nd more pr edi ctable th an the Yamaha 's quick-revving, exp lod ing-type pow erband. Comin g ou t o f tu rns, th e H on da has th e best lo w-end o f the [our bi kes a nd r o n tin ues to p u ll hard andsrnoorh unti l topped out in six th gea r. Th e Yamaha has decent "low-e nd , but th e transition to midran ge isn't as gradual as on th e H onda. On ce th e Yamaha co mes on the pipe, th ou gh , th e YZ hook s up very well a n d p u lls slig h tly stro n ge r th an th e H onda o n top; th e H onda still has stro nger low -end a nd m idrange. The Kawa sak i ma kes good power , but doesn 't have th e m idran ge punch it had la st yea r, o r th e year before. What th e '86 KX di d get , th ough, is mor e low -end, a smoot he r a nd more forgiving powerband. The Kaw asaki maintain s i ts qu ick th rott le response for fast acc ele ra tio n o u t of the turns. The Suzuki has th e weakest m otor o f th e bunch , bu t isn 't as far o ff th e pace as last year's Yamaha was. Th e Suzuki puts o u t a decent a mou nt of power, but what rea lly hurts it is that it' s a slow revver, Exiting turns, by th e ti m e the Suzuki co mes o n th e pipe, th e o ther three bik es ha ve already hooked u p and a re pulling a wa y. Once th e Suzuki ga ins so me rpm , it pulls a lmos t as strongly as th e o thers, bu t it's just 100 la te. Fan ni ng th e clutch o n th e RM is a co nsta n t must ; even th en , the Suzuki has a h a rd tim e keeping u p . Th e thrott le mu st be held wid e o pe n a nd th e bik e revved out at all limes. • . , .. I • The H o nda and the Suzu ki produce the lea st amou nt of vi bration , followed by the Kawasaki. T he Yamaha vibrates m uch more tha n the others a nd quickly creates a sligh t tingling feeli ng in the r ide r's h ands. Mechan ica ll y, th e RM was the o nly bi ke to give us a ny probl em s. The bike was delivered set u p a nd bro kenin by U .S. Suzu ki Mo tor Corp. , a nd we wer e to ld that the bike had a bout an hour o f tim e on it. But aft er we rode the bik e a bout 30 mi nutes , the Suzu ki seized when a lmost topped o u t in six th gear. The cyli nder was trea ted wi th acid a n d h on ed , bu t a new sta nda rd- size piston and r in gs were needed. Shortly after we put everything ba ck toget her, the Suzuki tossed its cha in , despite th e [act that th e ch ain was co rrectly adj us ted . T he ch ain wadded up between th e co u ruersha ft spro cket a n d th e swingarrn and damaged th e ca ses in the process; th e damage wa s most ly co smetic, not enoug h to require new cases. We readj usred th e cha in, but it eve n tua lly derail led aga in . According 10 Suzu ki, if th e cha in isn' t exactly in lin e from sprocket to sp rocke t, th e pl a stic chai n g u id e acts as a derailler. Th e Suzuki uses a specia l #520 chai n with thinner , li ghter plates , and it wea rs o u t qu ickl y, adding to th e p ro blem. A no rm al-size ;:520 chai n G ill be used whe n rep laci ng th e stocker. Shifting wa sn 't as preci se and smooth as we would have lik ed o n th e Yam aha a nd Kawasaki . Ever y now and th en, th e Yamaha feels like it cli cks into the next gea r, bu t do esn' t, requiring a nother jab o n th e shift lever. Th is happen ed more often whe n th e bike wa s brand new . Th e Ka wasa ki is reluctant to shift u nder a load with out th e clutch , especia lly 0[[ th e sta rt ing line. Sometimes th e sh ifter won 't bu d ge un less th e th rottl e is comp letely hacked o ff. Wh en the clu tch is us ed , th is p robl em occu rs less o fte n . We had no prohlems a t a ll shi fting th e Suzu ki or H onda. It 's hard to fault th e rear sus pe n sio n perform ance ' of an)' o f th ese bi kes. Basica ll y it comes down to a rwo -wa v tie be tw een th e Suzu ki a n d Ka wasak i. Asked to chose o ne as bei ng best, we 'd h a ve to go with the Ka wa sa k i Uni-Tra k syste m . T he backend on the Ka wa saki is pl ushier a nd more sta ble tha n the o thers o yer rea lly n ast y st uff , a n d it doesn ' t bo tto m ha rshl y. Landings o ff la rge, fast j u mps a re smooth . Th e Suzuki 's F u ll -F loa ter suspension works eq ua lly we ll ove r th e sma ller bumps, but doesn' t ma ster th e h ol es o r sq ua red-off bum p s quit e as ni cel y as th e Ka wasa ki. O ur first impression of the Yama h a 's Monocross syst em was Iav orable, but the more we rode the Yamaha , th e less impressed we beca m e. After mo re us e, th e Yama ha -bui lt- to- O h lin s-specifica tions shock sta rted ge tting springy and bottomed harsh ly over la rg e bumps; but it never lost its smoo th and co ntro ll a ble reeling oy er th e sm a ll , squared-orr bumps. The Yama ha's rea r en d tends to kick when launching off half-hikele ngth-size jumps, noti ceably more than th e o thers. The Honda 's P ro- L i n k is much im p ro ved ov er last year's; although very good , it isn 't as precise or predicta ble as th e other s, even when compared to th e Yamaha. The H o nda 's Showa sh oc k co mes stock with too much co m press io n damping for our taste, ca us in g the ba ck end to ho p too much, so metimes heavi ly. And when land ing o ff large, high -speed bumps, th e rider has to tigh ten up for a rough lan d in g . Desp ite the hea vy co mpression. t he P ro-Lin k gets the job do ne . Even th ough th e H onda 's rea r suspe n sio n is n ' t as pleasan t as t h e o thers , th e H o nda ma kes up for i t w it h superb [arks. T he Ka yaba fork o n th e H o n da a bsorbs a ll th e bumps wit hout any jolts or shaki ng, which really co mes in handy du ri ng a long motos . Th e Yamaha , o n the ot h er h a n d , (wh ich ha s th e most co m fo rt a ble rear suspension ov er sma ll -bu rnp s) has th e worst [a rk s. Out of the r ra te, the YZ's fro nt endis way too

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