Cycle News - Archive Issues - 1970's

~GP machiney (Continued from page 25) fa ct ori es were ex perimen ti ng with four-sp eed . a nd even th ree -speed gearboxes in '76 and '77 on the factory m orocrossers, With th e return to to rque as th e goa l fro m lon g-t rav el , the big -in ch m ot ocrossers a nd resu ltan t lon g st rok es, it would see m feas ib le. The on ly European bik es co ntesting the ent ire G P circuit t his seaso n are Husqvama , Maic o , and KTM . It is no co inci dence t ha t th ese m arques a lso offer th e m ost co m pe ti tive production , motocrossers from across the Atl antic. Herbert Schmi tz tied for firs t at th e 1978 USGP o n points in the best Maico m ounted USGP performance since 1973 when W illi Bauer won . T he m a chine looked very sta nd a rd, a nd it mi ght ha ve been j ust that if the works , bike had go tten to the U .S. a ny lat e r than it d id (The a ir freight g uys lost it for a couple of d ays .) , The best successes this year have come usin g the newly d esigned refined 440 cc engi ne . Power deli very is less abrupt and , of course, th e engine revs a bit high er to squeeze out the top end horsepower . A 36mm Bin g T ype II carb is attached without any ot her tricks at thi s point. . With th e new engine ca me a new fr ame a nd a lum inu m swinga rm tha t retains the sa me shape as the lo ng, p roducti on m odel. It bent acco m moda tes 15.5-in ch Ohlin shoc ks with an effec tive 11 .5 inc hes of rea r whe el travel. Mai co's o wn a ir a nd spring su pported forks have been stretche d ou t to m a tch . Fram e geometry is essentia lly th e sa me as current p rod uc tio n bikes, but the lightweigh t tub ing brought t he weigh t down to 21 8 1bs . In terms of shape , susp ension typ e a nd m ethod , a nd powerplant th e " works" Mai co is so clos e to sta nd a rd that th ere's not much to talk a bout. As o ne Maico m echanic put it , " Ma kes it easie r to ge t parts that wa y, doesn't I it?" H akan Andersson's ridi ng ca ree r has come full circle as he finds himse lf back on Husqvarna after nearly eig ht I years. The Husky th a t he rode at Carlsbad had the new dual ba ckbone fr ame that is a sig nifica nt desi gn departure from Husky's previou s philosophy. Chuck Sun is a lso trying it in th e AMA Nationals, a nd it is sch eduled for production next yea r . It is very heft y: Designed to a bsorb for ces ' rather than transmit the m - except it' s not really that sim p le. Available engines range from 390cc to 430cc . T he 400c c engi ne was bolted up fo r th e U .S. round . The bore a nd stroke were given as 86mm and 71 mm . That particular e ngi ne used a 36m m Mik uni but t he ca r b size will vary . The Husky-introduced six petal reed val ve between carburetor a nd com es cylinder. T he six-spee d gea rbo x whi ch provides so much course flex ibil it y is ret a in ed o n th e works eng ine . Offi cial weight is 221 Ibs . The air fork that Husqva ma has built fo r th e GP bik es provides th e increa sin gly co m mon 300 m m (a pp rox . 12 inc hes) tra vel. Remo te reservoir Ohlin d ampers a re hooked u p to a very swinga rm to len gthy-appearing p rovide 320mm (ne a rly 13 in ch es) of ' rear whee l travel. The new frame , swinga rm and sus pe nsio n' ge nera te a wh eelbase of 59 inch es which has to be one of th e longest in current m otocro ss racing . The Husky probab ly tracks like a m onora il. T hey a re slicing it closer than m ost in th e 500cc cla ss o n pre -mix , however, with a n eig h t lit er ( 1.8 gallon ) fuel tank , Most of th e ot he r bikes used nine-lit er tanks a t Carlsb ad . KTM is givi ng th eir new, "big" en gine a try-out in GPs this yea r. T he 420cc cylinder also has an a ll-ne w clutch a nd lower end to go with it. A 40mm T ype II Bing ca rbure ts th e beast without ben efit of reed va lves or othe r appurten ances. Ther e ' a re actu ally three versions of the KTM "400" a vai la b le a l. 352cc , the 420 , a nd a 460 . The 501 already m ention ed will not find its way int o a ny m ot ocross GPs unl ess th ey ca n sign King Kon g to ride it. Besid es, it' s too big for th e Velthoven's works class. Van m ech anic. Otto , hon estl y di dn 't remember th e internal di m ensio ns of thi s particul ar engine exce p t that it was still undersqu are in th e design tradition of Ing. Morowitz - who designs ver y qu ick motors back in Matt igh ofen . . j aa k's bike has 280m m Ma rzocchi air forks while you ng Belgi an Andre Ma lherbe chose 300mm .a ir -sp ring Ma rzocchis. Both ma ch in es used Ohl in d am pe rs at th e re a r hook ed up to enorm o us a lum inum swin garms to give 310 m m rear wheel travel. They accomplished this with an 18-in ch rear wheel and the high profile 5 .10 Metzeler . T he frame has been modified from sto ck to a ccep t th e new , b igger engi ne. KTM ha s gon e fro m a six-spee d to a five-speed o n th eir mo to crossers because they really didn 't need the ext ra gear. The KTMs gi ve a very heavy-duty overa ll ' impression , like th ey just aren 't going to break . Finally, yo u shou ld know tha t th e factories a re having th e same problems as we a m a te urs in controlling th e drive cha ins over 300mm of travel with the impressive torque of cu rrent 500c c cl ass racers. Every co nceiva ble type of chai n g u ide a nd support a ppea rs from dua l rollers to rubbing blo cks to wrap a ro und c ha n nels at th e rear sprock et on t he Hondas. Mai co's design . approach of keeping th e cou nte rsbafr sprocket sn ugge d right up to th e swin garm pivot point still see ms like th e log ica l way to go. One of th e best things about the works bik es is th at they' ll probably ge t • int o producti on - soon , t*************~*******************************~ ~ For all fellow riders who helped * Bob Hayes #07c Republican Nominee 39th Assembly **************************************1ft******..J 39

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