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/126340
- I ~ E 00 l' 0') ....-4 10 ....-4 s-. (U ..c e > z (U 0 (Above) The angled swingarm allows the shocks to be placed more upright for more progressive damping. (Below) Kayaba air/spring forks allow nearly 12 inches of travel. engine with the kick starter. Unlike th e production YZ·250F Yam aha we reported on last week . the Kawasaki was an easy starter despite • its higher state of tune . which soon beca me obvious. Releasing the clutch i gear and keeping the revs in m id range. the Kawasaki ripped awa y sm a rtly with a blast of exhaust and ex I1losion of dirt kicked sky high. This sucker was really fast and its light weight helped accentuate the fact. The powerband was a good one. coming on strong a round 4, 000 rpm . and pulling strongly righ t up to about 8 .000 . Broad . qui ck revving and powerful . it seem ed to be th e ideal motor for the 250cc class . The only thing that might compare to it is the 250 CR Honda. a nd even then th e Kawasaki was faste r . Compared to Bob Hannah's OW· .38B National bike the Kawasaki would leave the Yamaha in a time-warp behind. Hannah's bike worked best between 3.000 and 6.000 rpm with lots of shifting. It would pull stronger at lower rpm's, but the Kawasaki exhibited what we consider tobe the ~rfec t 250cc class powerband with an excellent compromise between 'power ah d tractability. Under 3.500 rpm the Kawasaki didn't want to run well at all. but we felt this was due more to rich bottom end carburetor jetting than to a problem with really radical porting 'in the cylinder . Mickey Boone is probably 30 poun· ds heavier than ou r test rider, as well as being quite a lot faster . yet th e suspension was really soft and comfortable . Mickev cla imed that he liked his suspension set up on the soft side, wh ich seems to be the preference of most of the top riders now. With close to 12 inches to play with in the suspension. you can set a bike up soft for better rough ground tracking. lowering the ride height in the process, which keeps the bike manageable in turns when you need to put your foot down. And with a softer riding bike there's less fatigue for the rider and the chance of being knocked out of shape by a bad bump. The R2 was a little tricky to negotiate in slow sections , but th is is a problem common to all of the latest long-legged works bikes and a sacrifice well worth making considering how it behaves so fantastically in both the rough and on fast sections of the track. If the R2 could be compared with any other production bike presently available , the CR-250 Honda would once again be the closest. Chassis geometry and riding pos ition feel nearly identical , but the Kawasaki R2 would certainly come out on top with its better works Kayaba suspension components. From wha t we've ridden so far. in clud ing the National Championship and Supercross winning OW works 250cc Yamaha of Bob Hannah, we would have to rate the R2 Kawasaki as possibly the best performing bike , handling and powerwise, in the 250cc , class. But how does the R2 compare wit h its new production counterpart . th e yet to be released 1979 model KX -250? Press release photos show the production KX -250 to have simil a r rea r suspe nsion geometry to this year's earlier RI model works bike. And in nearly every detail the production bike seems to be 'a direct ' copy of the R 1. with the possible exception that the engine cylinder will have a steel liner instead of the Electro-Fusion coating, a nd the more production related suspension components from Kayaba won 't be up to works bike specifications and performance. Other than the 214 pound weight . we haven't been able to get any information from Kawasaki . but we would suspect the production K.X to have suspension travel in the 10-11 inch range rather than the R2's 11.7 inches. We'd like to see Kawasaki adopt the R2's revised suspension geometry to the production KX . The swingarm on Mickey's bike was a production aluminum arm which had been modified to the new R2 geometry, and if the production KX 's are as handbuilt in limited quantities as Kawasaki claims they are, then it shouldn't . be too major a problem to make the change before an entire model year goes by . • Kawasaki's 250cc pow erp lant incorporates an Electro-Fusion cylinder and radical porting t o pro vide rocket-like powe~ from 4,000 to 8,000 rpm. 25