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/126338
e , • ,e ~- e E 00 1:' O"l l"'"'4 l"'"'4 l-o THEVE BEST or (Continuedfrom page 25) fra~~e dow ntube. , The ign ition system is just as interesting . This year's model has a new CDI system, fired by a m agn etic trigger on the end of the cran kshaft. , I'he ignition automatically advances it~df 40 degrees BTDC over 250 rpm . To reduce weight and in crease power there is no magneto for generating ignition power. Rat her tliere is a small rechargable cell system inside the airbox with the CDI. After being charged on a small DC battery or_power source. the bike has enough juice to run 3-4 hours before another re charging is needed . We conducted our test of the 580cc at IMaplehurs; Cycle Park in Spring Grove , Illinois. Rid ing the bike for the phexo session was National motocross riatt' Bob Miller. who races a 390 CR Husky. Getting a proper evaluation of the bike was a little difficult since the bike was new and wasn 't full y dialedin _Time prevented us from getting the right volume and viscosity of oil in the frmt forks . as well as the proper air p ressure. The Girling rear shocks also needed mo re preload and perhaps a rate ch ange since the bike was losing tlii-re'inches of travel j ust parked. Carbu ~(ion was a lso lea n on acceleration and we d id n't have the prope r t hrottle slier to correct it. Still. feeling our way around these han dicaps we felt that if t he bike was set ' iip properly it could pe rform on pal (with a well-prepared productio n Open class two-stroke. It was fast . res{>!Dsive to rider inp u t , and handled w~~. The fact that it displaces 580cc mr~ht scare someone at first . but you have'to understand a four-stroke has a mo re tractable powerband than a twost e while that much displacement is needed to get a comparable horsepover rating to , for example. a RM400 Suzuki. Q.uite unsettling if you're not used to it il the right side shift/left side brake pedal of the English CCM. It really isn't much of a problem, though, because if you don't want to learn how to use them you don't have to . Just leave the smooth shifting bike in second gear for nearly every portion of the track , while igt!oring use of the rear brake entirely. The excellent front brake and engine braking of th e four-str oke engine will haul you down q uicker than must twostrokes using both b rakes. Act ual use of the rear brake in slow tu rns can st all the :engine, which brings us to the biggest d rawback of any Opeh class four-stroke - sta rting it. Despite all the goodies ava ilable like .Yam ah as compression release on their 500cc or CCM 's electronic advance timi ilg system, when it comes down to kicking over a big four-stroke. you be tter have a lot of time available an d patience. Starting is still an art re quiring amount of choke and throtI I , • .. .. . ... Or .. . . . . tie , locating top dead center, the m ustering up enough strength to spin the engine over more than on ce. Many' times you'll m iss the ignition point. or the fue l mixture isn 't just righ t. Something is never right and you have to either fin d a big hill to pu sh down , or expect to be where you are for a while before it does decide to fire up . This isn't too big a drawback if you have th e time before a race to get sta rted . but if you ever stall the engine during a moto. you're going to be a half lap behind or more before you're running again . The CCM . or any four-stroke, is also at a disadvantage on extremely rough tracks. The slower -reving powerband of a fou r-stroke makes it less responsive to quick throttle movements. Trying to loft the front end to clear bad bumps or whoops in seq uence is d ifficult and requires too much str engt h jerking on the bars to t ry and bring the front end up . Eventually you end up just crashing your way through . but sometimes the bumps on some courses are going to be j ust too bad for even the CCM's excellent suspension to overcome. A two-stroke, wit h double the power impulses of a four-stroke and less rotating mass , will always remain a more responsive power plant. The conclusions · to be drawn are thus : Having ridden other factory works bikes like the RC Honda and OW Yamaha . the CCM and other four-strokes are at a disa dvantage in both weight (b y about 25 Ibs.) and power (less response . less horsepower for ' equal displacement). All the Japanese teams have"faster , larger dis placement two-stroke works engines on the she lf, but they don't use them at all because they have more tractable horsepower than they can use now. Where the CCM is competitive is in local ra cing against equally heavy production bikes like the 400 Yamahas and Suzukis. On relatively smooth ses of sand, grass or loamy dirt, the CCM would even be at an advantage since it can pull strongly out of turns without bogging. And where CCM would excel is in four-stroke only racing where. compared to the heavier and smaller displacement Hondas and Yamahas , the CCMs would be real terrors . The C<;:Ms aren't cheap. $3350 for a 4-speed and $3500 for the new 3-.speed. But that's a bargain when you consider it is a fully assem bled bike. ' better engineered and wit h better quality parts than any other production bike. And it really costs no more than it would to build u p a HallmanYamaha or Knobby Shop-Honda from kits with the best components. What it all thumps down to is what kind of racing you're doing , and how well you like the mellow sound of a big thum,per reverberating offthe ~?~! ~!~" ~ _', V ..c 8 V > 0 Z 60 pages Order :::::: ..." YOur COlllic Book today ONLY 7St ., • • • • • • • • Send • • Check or Money Order•to: • • • • • Cash. • • • • • CYCLE N EW S PRODUCTS P.O . Box 498 Long Beach. CA 90801 copies of Please send m e the MX Cat Comic Book Dea ler Inquiries encouraged! • • • • • Name (Please print legiblyl Address • • • • • • • • • • • • • • • • • • • • • • • • • • • City State ZIP 39 .