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/141065
co '" l" M .... '" '" c ": .., " ;g W Z W ...J U > U " .. Photograp hy by Art Friedman and Dave Sc hoon make r The Yamaha 100 and 125 MX's Whil e th e 10 0 and 125 Mo tocr oss Yamah a are two ve ry diffe rent little bikes , we're go ing to lump th em to geth er. Th ou gh th ey rid e very di ff er ently, they 're th e same sort of so lution to the same so rt of prob lem . They're a J ap anese answe r to an Am erican prob lem : che ap tran sportation arou n d mo to cro ss cou rses. Both th e 100 and 12 5 can be had for a little more than haI f of what th e really ex pe nsive Euro pe an 100's an d 125 's will cost. Th at in itself ma kes th em inte resting bikes to take a good hard look a t. Here' s wh at we fou nd . Bo th bikes ar e con verte d End uro models. T hey ge t sn ap py pain t jobs, wild p orting, al tered gea ring: the ligh ts ge t str ipped o ff, and, in the case of the 12 5, the seat is ch an ged . In o rde r to em p hasize their heri tage, th ey both h ave w irin g h arnesses dangli ng d own from up h y th e tank. The cente r stand and ignition swi tc h moun ts an d other assorted b racke ts rem ain . 2 1" fron t rims (steel), knobbies , and, of course, silen ced ex p ans io n chambe rs co mplete th e p ic tu re . Both bikes lo ok simila r to th eir larger bore rela tives, but looks are ab out the end of the res emblan ce . T he' 250/360/ 500 Yamah as are specialize d motocrossers , n ot conve rte d e nd uros. . Nei th er of th e small b ik es go t re mote reservoir sh o cks. T oo b ad , th e ones that co me on th em don 't work. The price tag just went up 50 bu cks. Th e 125 has aluminum slider forks that can be made to work ade q u ately, and , while th e 100's forks are s te el , th ey also seem to get tile job done in an average mann er. Th e wheels, suspe nsio ns, a nd frames add up to bikes that st eer mu ch like their end uro relatives. Both are qu ick: steering into co rners is an eas y matter. Th eir sh o rt wheelbases ge t things done in a hurry. How ever, th ey are di fferent to ride becau se o f their availa ble n othin g h appen s eno ugh powe r. T he 100 is ve ry pip ey, Torq ue is to write home abo u t and acceleratio n in a big hu rry. On a smoo th tr ack the re's tim e t o ge t so me sliding d on e without disastro us results, b ut in m o to c ro ss it require s too m uc h effo rt to d o so . T he 12 5 has eno ugh ad d itional to rq ue to allo w hi g, hairy slid es. It d oes them ve ry well. Just lay it over and wring it 'o ut . It never seems to want to slide o u t. Com b ined with it s q uic k handling th is attrib ute makes th e 125 ~lX a fu n little pl aybik e . It ' s kin d of hard not to be a pi t sq uid . It 's a little difficult to an alyze eithe r bike's hi gh spe ed handling becaus e o f th e sh o cks . On an y kind of b umpy te rrain , they became treache rous. The 125 is faster so it handl e s w o rse, T he rear e nd wan ts to be in fro n t of the front so b adl y it 's amazing. Th e shocks probably co n trib u te d to so me o f th e he a rty tank-ban ger s, t o o . Th e 12 5 (in s toc k s tate) is the so rt of bike that when yo u ge t in troub le you know yo u are n't going to ge t out of i t. T he re's usuall y some time aft erwards t o con te mp late the stars and anal yze just what happened . Our susp icion is that with decent shoc ks it would work re asonabl y, right up to the p oin t of trouble, and then it would still spit yo u off. T he 100 is be tt er than th e 125 on ly becau se it is slower. The 100 didn't cause nearl y as man y big eyes. T he motors are the best p arts of eac h unit. Whil e b oth are peaky th ey ar e also pretty quick. Probably j us t a h air off the to p compe ti tio n. Bo th have reed valves , an d b oth ran very cleanl y throughout th e test. As y ou mig ht expect, they ar e low maintenan ce engine s. Oil inj ection and pre-mix keep th e in n er workin gs as slim ey as th ey mi ght eve r want t o be . The injection is n ice, but b oth bikes carry large, heavy o il tanks high on th e chassis. You 'll probabl y want to , , '. 1 ..• - ~. , ~ .~ T he 125 had enough power to deal w ith sliding situati ons. Hillcli~bi ng the 125 was a chore . The pow e r was there , but when It came on to the power band it wanted to . play loop-the-loop. Add to that tractio n diff icult ies because of t he poor rear suspension , and y ou have a handfu l.