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/127772
TWO-STROKE CHALL ENGE RS Wha t did MV have to build two deca des ago to throw up that final barrier against the advancing two-stroke hordes? Basically, it was a refined version of the layo u t they used when they sta rr ed in 500cc GP racing in 1950: a transverse ly m ou n ted four-cylinder, twin-cam engine, just like today's Japanese st reet bikes. Tha t early machin e gave just 52 bhp at 9500 rp m, but MV developed the formula to win 18 500cc world champions hips betw een 1956 and 1974, with rid ers John Sur tees (a frequen t visito r to Da ytona tod ay), Gary Hocking, Mike Hallwood, Agostini and Phi l Read. In . the late '60s and early 70s, MV chopped one cylinder from the package to deliver a narrower, better handling bike, before d esigning a much more compact fourcylinder engine for the ir final years in . racing . There were also 350cc versions of both three- and four-cylinder bikes, which won another nine world titles. But by the mid-70s MV was struggli ng to ward off the explosive power being developed by two-stroke engineers. A two-stroke motorcycle had first won a Grand Prix in 1952, when Germany's DKW factory competed with a crude twin-eylinder 250. But it wasn't until the East German designer Walter Kaaden of MZ solved the problems of efficient cylinder-head porting and the mysteries of exhaust resonances that "strokers" mad e real pr ogress. H is techniqu es were exported to Japan when his top ride r, Ernst Degner, defected from behind wha t was then the Iron Curtain and joined Suzuki. Degner recorded the first world championship win on a two-stroke, in the 1962 series for 50cc machines. His incredible bike had a single air-cooled cylinder wi th a disc inlet -valve, and needed an eigh tspee d gearbox to make the best use of its meager eight horsepower. It weig hed just 132 pounds, and had a top speed of only 83 mph. . Two-strokes bea t the fo u r -s tro ke bikes in the 125 and 250cc classes in 1963 and '64, but had to wa it until the 70s b ef ore their reliab ility w as s trong enoug h to take on MV in the 350 and 500cc d ivisions. During this time the great Japanese GP w ars were foug h t o u t be t w een Honda, Yamaha a nd Su z u ki, with Honda bu ilding some of the most techn ically in n ova ti ve m ot orcycles ever made to keep their fou r-stroke technology ahead of the two-stroke factories. Honda designed tw in -cylinder 50s and 125s, four -cylinder engines in 125, 250, 350 and 500cc capacities, a fivecylinder 12Sec machine, sixes in 250 and 297cc variations, and at one stage even planned to race a three-cylinder 50cc bike. The bizarre noises made by these unsilenced engines shrieking at up to 20,000 rpm sent spectators into frenz y you could even bu y long-play ing records of Grand Prix bikes in action at the Isle of Man IT races! THE DEFEAT OF MV For several years, Honda's radical engineering kept the two-strokes at bay. But not even the Japanese giant, and the soaring talents of Mike Hailwood as rider, could budge MV Agusta from the 500cc championship. Every year from 1958 onward the Italian team managed to hold onto the biggest prize in GP competition. Then Honda pulled out ofracing at the en d of 1967, leaving only MV as a serious four-stroke contender in the bigger classes. For a time things looke d goo d: Two-stroke technology was still unabl e to produce a big-bore engine that could prevent its me ta l 1996 "lATIONS FIRST OUTDOOR IVCTOCROSS. NATIONAL OF 1886 $ 3 0 .0 0 0 PROF:ES SIONAL PURS E 3 B I G DAVS ay, Marc oaytona SUZUki Amateur National Supercross COntingency Round * Dunlop Test & Press Dayfrom 12:00-1 :00 P.M. * from 8:00-Noon * * Special Autog raph Session ay, Ma Amateur National Motocross ay, Marc Pr o 125/250 Motocross Nationals See all the National Motocross Stars On The Famous Gatorback Track Gat es Open 6:30AM - Gates Close 10:00 PM Registration 7:00 - 8:30 AM Amateur Registration at Track , $25 Per Class ALVA AMA and World Sports Membership Required. Available at Registration. IANeTIONID GATE FEES FRIDAY, SATURDAY, SUNDAY ADULT $30· UNDER 10 (NOT RIDING) $15 FOR INFO CONTACT: WORLD SPORTS 9770 16th Street North St. Pete, Florida 33716 (813) 578-1776 SATURDAY-SUNDAY ADULT $25· UNDER 10 (NOT RIDING) $10 SUNDAY ONLY ADULT $15· UNDER 10 (NOT RIDING) $7 ~ ~ Uiii &ai1i:;~ s~ ! em: i"A~!fL!j, EE9 • •• • I . . .. . #1M r-----------------------------------------------, PERFORMANCE ENG! EERlNG EKohain . Rentllal <€-11?> hammerhead gr.ph lcs Attach Label Here ? ~. ... For FASTEST service attach mailing label. Please allow 3 weeks (or change to take effect. If label is not available print your name and old address in this box. Print your NEW address here. NAME . _ ADDRESS L CITY --'_ _ STATE ZIP Mall to: Circulation Dept. Cycle News, Inc. 2201 Cherry Avenue, Long Beach, CA 90806 ~ 49