Cycle News - Archive Issues - 1990's

RIDING IMPRESSION ~¥1999 Suzuki'RM125 and 250 . ( {~ '. Photos by Kinney Jones ast mont h, we showed you ph otos of the 1999 Suzuki RM125 and 250cc .-...J. MXer s, but at that time little technicalinforrnation was ava ilable abou t the bikes. Since then, however , Su zu ki ha s provided u s w ith furth e r d etails abo u t their new bikes and , to make us eve n ha p p ie r, th ey eve n gave us the op po rtu nity to sp in a .few lap s on preproduction versions of these bikes. Bo th th e RM 125 a n d 250 too k on many cha nges to the mo tors. The 250, for ex a m p le, feat ures pretty m uch an a ll -n ew cy li n de r a n d top en d : Th e exhau s t power-v alve sy ste m has been red es ig n ed , th e e xhau s t-p ort s h a pes an d tim ing have been altered , and the p ist on fe atures a n ew d om e-sh a ped cro w n w it h a Black Flu or o-compou nd su rface treat ment, w hich Suz uki claims increases su rface ha rdness and red uces friction . Elsewhere in the mo tor , the cra nkshaft inertia has been increased for "better pow er d elivery and engine acceleratio n ," o r s o savs Suzuki , a nd th e cra nkcase itself h~s also been tw eaked , as has the in take area. To improve engi ne cooling, the 250's radiators are now a little larger. Su zuk i we n t searc hing fo r m o re mid ra nge ou t of th e RM125' s a lre ady p oten t m ot or in hopes of makin g th e bike a little easi er to rid e. Like the 250, the 125 gets increased crankshaf t inerti a, it ge ts the Black Fluoro treat me nt to the piston , and it now gets a power-jet-type car bureto r. But the 125 did take on a few cha ng es of its own, like a 2mm-lon ger connecting rod , a larger-cap acity clu tch with stiffer sp rings, and a new clu tchrelease cam . The ignition-timing curve has also been altered . Whet her o r not co n ven tio nal for ks a re better than in verted fo rk s for the "a vera ge" ri d e r is a deba te that w ill most likely go on for years, bu t Suzuk i feels - a t least from its marketing point of view - that the u pside-d own forks ar e the way to go. After all, how can Suzuki convi nce the consu me r tha t conventiona l for ks are better tha n in verted forks when their ow n race-tea m riders have We recently got t the chance to s pin a few laps on '99 • preprodu ction I RMs at Glen Helen Racewa y, A new top end has breat hed new life into the RM250's • motor. switched from conventional to in verted forks? That's a tough sell. So. for 1999, Suz uk i has gone back to equ ipp ing th eir produ ction RMs w it h inverted forks. These Showa TwinChamber forks, howev er, a re m u ch di fferent th an the previou s inv ert ed for ks found on the RMs three years ago . They' re bigger and feat u re differ en t internals, an d they're also lighter than the con venti onal for ks th e y re p la ce . Th ey a re al s o fu lly ad justa ble, with 16-way compre ss ion and rebound damping adjustme nts. Suzu ki managed to ge t the RM's rear su spension wo rking pr et ty good in '98, R EI ~ ~ 00 0\ 0\ ...... \0' C'l ..... CFl ~ 0.0 ~ -c 36 The preproduction '99 RM125 still rips but has more midrange, making ' the 'bike eas ier to ride. so they pretty m u ch le ft well enoug h al one, althoug h th ey did make minor d amping cha nges , as w ell as making an attempt to improve bottoming resis tance . Th e mai n lin k is a lso ch a nged slightly, but Suzu ki reports that the linkage ratio did no t vary. O ther chassis cha nges include go ing to a 20mm-Iarger-di am eter di sc-brake ro to r, and goi ng to a d ifferen t brak epad material, w hich is also the case up front. Bot h RMs' rec ei ve n ew , one-p iece cha in guards. Our br ief stints on the '99 prep roduction RMs we re jus t tha t - brief. But if the b ik es w e rod e are a n y th ing li k e th e soo n-to-be-re leased produ ction bikes, the n Suzuki has a pai r of quality bikes . on their hands. Of the two RMs, the RM250 appears to be th e most im proved - it now has power, and lot s of it. In reality, the '98 RM250 was no slouch. It made decen t, u sabl e po w er , a nd som e rid ers ev en co ns idered the '98 as being fairly fast , but th e genera l con sensus was th at it lacked that exp losive hit and hard pull that bikes such as the Honda CR250 and t h e Kaw a s a ki KX250 d eli v e r . Th e RM250 pro totyp e w e rod e was d (i wnright powerful , and we wou ld conside r it to be in the sa me lea gue as th e '98 Kawasaki and Hond a, which will certa inl y make a lo t of Su z u ki d iehards very happy. The di fferences bet w een the '98 and ' 99 RM125s are m o re su b tle as com pa red to th e ' 98 a nd ' 99 RM250s. The already fas t RM125 see ms to have been mad e easier to ride than ks to a bit more bo ttom-end and midrange power. lt still hau ls on top and revs to the moon , but

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