Cycle News - Archive Issues - 1990's

its lack of low-end grunt. Clea ring do uble or tabletop jumps that are preceded by a sharp turn wasn't as easy aboard the modified YZ as it wa s o u r s tock Honda CRl25. But what about the suspension ? With the 12 years of experience ga ined while working for Showa, Sam M ishima. brings to R&D a wealth of susp ens ion tuning knowledge. "I read in your 125 shootou t that you were already pretty hap py wi th th e YZ 's s u s p en s io n, " Mishima told us . "So I only changed a few littl e things." . Tru e, we were already quite pleased with the pe rformance of ou r stock Kaya ba forks and shock, but w e're always willing to try so mething new. Mishima believes that the "m id-v alve" se tup in the Kayaba fork delivers a harsh feeling in the low- to mid-speed com pression dam ping. In order to eliminate this harshne ss, Mishima simply" elim ina ted the mid -valve altogether. But wouldn't that be like cu tting off a motor mount in order to m ake yo ur bike lighter ? Well, accord ing to Mis hima, not if you compensate for it. The high-speed compression damp ing wa s increased in order to make up for the now-absent mid-valve, while the rebound damping was dia led in to have a little less low-speed resistance, but more high -speed. O u t back, the Ka y ab a shock wa s reva lved in a similar fashion. Less lowspeed , and more h igh -speed compression damping was the theme. Rebound was left stock, a nd the sag was set at 95mm. Accord ing to Mishima, th e se w e re se tti ngs that DG Y rider Jeff Dement used in the 125cc Nationals last year. Like the motor, it was hard to truly evaluale the modified suspension during our first outing. The rolling sand whoops were handled equally as well by both the stock and modified bikes, though we will admit that the R&D suspension seemed to resist bottoming better. At both Rain bow and Glen Helen, it was much easier to p ick ou t the differ en ces betw een the tw o. The R&D bike ha d a plush er feeling in the initial parts of both front and rea r travel. By loosening u p the lo w -spe ed co m pressio n dam ping in the fork and shock, Mishirna ha s allowed the YZ to deliver better feel ove r the sma ller bumps and square edges th at often form goi ng in and out of comers. Thanks to the tig hter h ighsp ee d co m pressio n valvi ng, th e R&D boi ngers hand le hard landi ngs with greater con tro l th an the stockers - bottoming is less frequent, even wi th a 170pou nd rider aboard. In order to put the YZ's new-fou nd power to the ground, we installed one of AF AM USA's Type II Hard Anod ized Chain Kits. Included in the kit is a highquality MCZ cha in, which AFAM claims is h ead and shou lders better th an th e s tock u nit. From the materials used, to the sho t-peened, heat-treated finish, the MCZ is far from ave rage. A Works Light II h ard-an odized rear sprocke t, and a case-ha rdene d steel countershaft sprocket ro u nd ou t th e package. Both ch ainwheels featu re self-cleaning grooves. Thou gh AFAM is best know n for their ch ain s and sprockets, they ha ve developed a line of handlebars to complime n t their exis ting line of products. The M5 Works Bars are constructed of 5mm-thick 2014 T-6 alu minum tubing. AFAM claim s tha t the bars are mu ch stronger tha n othe r al uminu m handlebars , most of which use 4mm-thi ck tubing . We chose th e high Hon d a bend, wi th a purple anodized finish. Each year, we a cq u a in t ourselves with ap proximately 10 new mo tocross bikes. And usually, the first things to go (Above) R&D Racing worked mag ic insi de the yz eng ine. Extensive internal modifications and an exhaust system gave the yz some serious bark. (Above) The MMF Radiat or Guards look Indestructible. So far, they have been. (Left) The Afam MC2 Chain suffered almost no st retch, and the Works Lite II Sprocket is stronger, lighter and more durable than the stocker. are the hand lebars and the cha ins. Being the wild lot of testers tha t we are, most stock bars only last a few rid es 'b efore b ein g b en t bey o nd recognition . The stock chains, meanwhile, usu ally stretch lik e rubber bands and don' t last long . Tigh teni ng th em repea ted ly u sually only wea rs ou t the sprockets - repl acing th e s to ck ch ain quickly is u suall y th e best solution. So far, o ur expe riences with th e AFAM handleb ars, sprockets and chai n have been quite positi ve. Other than a tiny bit of initial stretch, the MCZ chain has resisted stre tching, eve n in sandy or muddy co nditio ns . The Works Lite II sprockets d o a good job of alleviating th e mu ck th at usually bu il d s up between the chain and sproke t, th anks to their self-cleani ng grooves. The M5 Wo rks Bars seemed to tr ansm it a bit more vibration to the rider's hand than say, a p ai r of Ren thals, but are mu ch to ugher a n d bend -resis tant. We attribute t h is to th e ir th ic k e r 5mmwa lled tubing. Pro tection was the next order to be filled, and Mike Mea de's MMF Racing was happy to oblige. MMF sup plied one of th e Stad iu m Ski d Plates, a p air of Frame Gua rds, a p air of h ea vy -duty Radiator Guards, an d a trick Aluminum SubFrame. In addition, ou r project YZ was p ropped u p on a new Alu mi num KwikStand. All of the alu minum pieces bolted on wi th min imal amo unts of grief. In addition to better roost protection, the radiator guards ad d so me side-impact protection as well - a defin ite bonus whe n a radiator can' cost well over $100. In com- . pa rison to so me ot her skid plates, the MMF u ni t bolt ed on with simi lar ease, but features a sma ll lip near the front. Why? "A s a mudguard," said Meade. "Stuffing foa m betw een the frame and the skid pl ate is a h as sle, and it also sta rts to loo k bad . The lip on the fron t of our skidplate keeps the mud out in the first place." Roun ding out of project YZ's appearance was a set of Acerbis fenders, radiator shrouds and sidepanels. In order to dif- . ferentiate our hot rod from every othe r YZ on the race trac k, we opted for the deep-purple-co lored p ieces. We ' re not sure whether it was the plastic, the MMF subframe, or a combination of both - but the side panels and rear fender required some drilli ng be fo re th ey co u ld be installed . Other than that, the fit, appearance and qu ality of the Acerbis parts rival the very expensive OEM pieces. . Looking at th e fu lly asse m bled machine, so mething ju st d idn't look right. Of course - there were no n um bers on the bike! N-Style's pre-cut n umberplate backin g and 8-inch Pro 's gave ou r bik e the finishing tou ches, but owner Rob Hea ly begged us to wait a few mo re days for his '95 line of Im pact Gra phics to arrive. As it turned ou t, it was wo rth the wa it - N-Style's '95 Impact Graphics kit for the YZ125 is the bes t we 've ever seen . The p redominant ly purpl e sticker kit fea tures a comput er -gener at ed pa ttern that gives it a 3D effect. Sano. The grand total, should you deci de to buil d a re pl ica of o u r m a ch in e , is a whopping $1826. Qui te a hefty sum, considering tha t a brand -new '95 YZ125 costs $4249. But of the three classes - 125, 250 and 500·- the 125cc d ivision features the m ost h ighly modified m achines . While most 250, and certainly the majority of 500 riders, can be perfectly happy with a s tock mot orcycle, a lmost every 125 racer can be heard crying for more and more power. So why not go ballistic with the budget? A bike sho uld look as good as it runs, shouldn't it? YZ Warriors, eat your hearts out.. . Cl\' . :What they cost .- " . . .;' Who' "ya"~oiIna tall? .: Acerbis Front Fender ' • . .'., • . . . . . . ~ .. . . . : $28.50' . .. Acerbi; USA ': . Acerbis Radiator Shrouds : . .': . . .'. •• ;.. • . •.. $48.95.. 9402 Wheatlahds C1. SuiteA AcerbisSide Panels .'" . . . ; .. '.• '.. : . : •• . . , $54.95 . Santee. CA 920 . '. . 71 Acerbis Rear Fender.·. , . .'. , .:', .'.. " . :..... . $29.95 . 619/562-1440 AFAM Handlebaril' . . .: . . , : .. .'. . , . .:.. , . : $65.95 'AFAMType II Hard Anodized Sprocket kit . $136.00 " AFAM USA MMF Stadi\JmSkidPJate ..'. . . .... , • .'.... ; .. $48.95 . 5953 Engineer Dr. . . ' . MMF Frame Guards .: . v. ; : . • •'. :' • : .: • •'. ; $48,95 . Huntington Beach.C,a. .92649 . MMF Radiiltor Guards .. : ., : . . $48.95' . .800/290- 040 ' . 9 MMF Aluminum Subframe .' : : $179.95 ' . ' . . ' . ' ' . MMF Aluminum Kwik Stand ': .'. . • . : . ; . : $69.95 ' .. MMF Racing ' .' N·StyJe Impa GraphicS . : . .'• . : . ; ; Ct :.:' .$59:95 .. ' 12145E Slauson Ave, . . N.StyleSeal Cover , , .', . •. • . . , . . , $49:95 Santa Fe Springs. CA ~70 N·Style Pre-eut Nurilberplate Backgrounds ., $21 .95 . 310/693-9096 N:Style Pros . .. .. ,., . : '. ' , : . . .. , .. , ' . ...-, ; $7.95 . N·Styki . . . N·Style Rear Fender Sticker Kit ." . . " .., .'. .$14.95 . .": 2781 1 Avern.ieHopkins'#2 R&D Exhaust Pipe , .,; : .... , . . ,', .$165.00 ValenCia, CA 91355 .. . Fl&D Cylinde'rMods . . :· ,·. , .:; . . . .'. .• . : . .$275 ' 8051294·1 118 (including $25 vaJvemods) .. .. . . R&D Head Mods . .•.. : .. . .' ,,: : . , . . ,'. $75:00 R&D Racing ' . R&D Fork Mods :..; : . . . : .. : . $175.00 '. 11419 Bombardier : .R&DShock'MOds .: : .:. , ; . . ,', , ., . • . , $1 75.00 .. Norwalk. CA 90650 R&D Calbon Tech Ca rbon Fiber Ree<;ls ·. , .'; , $38.00.. . 3101864-8218 ' .' . . ~ ~ ' 11") 0\ . 0\ ...... -.:t<' ;;:..., I-< (\l ::l ~ (\l ......., 57

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