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/126635
- .l-l .... 0.. < land - repainted th e bikes in red and black Garelli livery, and the rest is h istory . After a gapof 50 years' absence from racing, Garelli -one of the world's oldest-established bike manufacturers who beat th e likes of Guzzi and Gilera to Grand Prix success with a th en -unfashionable split-single 350cc two-stroke in the early twenties - won th eir fir st World Championship titl e at th e initial attempt. Just what is it about the Garelli 's speci fication that makes it stand out in a hotly-contested class whose regulations appear to im p ose a uniform design of parallel twin-cylinder dis c- valve engines with six-speed gearboxes and wat ercooling?To a certain extent . the answer lies with Moller's original - design which produced a remarkab ly l~ com pact engine unit that measured 15" across with the 29mm Dell'Orto carbs removed. Th iel 's reduced this even further to just under 14" across, an d combined wi th th e very low monocoque fram e and highly efficient strea m lin in g, devel oped in the Fiat car firm's wind tunnel , this very sm a ll frontal ar ea and th e en gine's amazin g power resu lt in a top speed of 145 mph - from 125cc! But thi s low aspec t calls for speciall ytail ored rid\,rs ,- .star midgets able 10 mold th ems elves to the tin y ma chine, heads under th e scree n, elbows and knees tucked in sid e th e fairing, chea ting th e win d of every o u nce o f drag. As Patriganan i had noted, I'm no Nieto, a n d jacking m y kn ees up high en o ugh to fit th em on to th e footrest s was a ma jor proj ect. Keeping m y legs tucked beh ind the fairing wa s no problem since it's quite wide thanks to th e cra n kcase-mou nt ed carbs, but I was quite unable 10 get my head inside the screen with a helmet on, and it took quite some time 10 figure out how 10 change gear with m y size nine left boot. Nieto has somewhat smaller tootsiesl The overwhelming impression wh en you first see or sit on the Garelli is how slim it is. Three years a fter Mijwaart designed the first steel monocoque 10 replace th e less rigid tubu lar frame, th e Gar elli and the KR500 Kaw as aki a re th e onl y GP bikes outside th e tidd ler 50cc class 10 emp loy thi s type of ch assis - if o ne excep ts th e NR 500 Honda of sporadic appearance. T he mon ocoque's made of dural now , weigh s a sca nt 13 pounds a nd co nt a ins four ga llons o f 50: I mixture in th e ba££1 ed fu el cell. It 's a lso extremely ri gid. a nd the wo n de r is more race bike design ers haven't o p ted for this design. J an Thi el th inks he kn ow s wh y: " It reall y o n ly works with a twin -cylinde r en gine because of sp ace limita tions and yo u hav e to design a bit o f extra strength into th e engine ca ses 100 . It's difficult with four cyl inders to sq ueeze th e exhaus ts too. It 's in, which is why I adm ire the Kawasaki so much - th ey did it really well. " Admiration extends 10 outright copy ing of the KR500 's mechanical ant i-dive front sus pe nsio n, itself borrowed from the Udo Geitl BMW Superbike ridden by J ohn Long in the mid seventies in America, a nd here mated to 32mm Marz occhi forks . The effect is stu pe fyin g ! R ush up to a tight corner at top speed, leave you r braking impossibly la te, gr ab th e front brake as hard as yo u like in th e dry. zip down through the box and whil e yo u' re doing it a great big h and ha s reached o ut and halted your progress. No divin g forks , no cha ue ring rear wheel , no tran sfer of weight o n to th e wri sts - th e C arel li just sto ps, in a perf ectl y level plane, th e system of rods transferr in g th e brak ing forces from th e ca liper to th e steeri ng head in a sim p le but effective manner. Everv bik e sho u ld have o ne! O f co urse, th ere'.... ot muchto.hau l sn . _., .. .... do wn , relati vely spea king, th ough a t 172 pounds dry , the G ar elli is still so me 6.5 pounds abo ve the 125cc clas s weight limit. Thiel h as pl ans to narrow this gap, with Kevlar stream lining scheduled to replace th e presen t sea t a n d fairing, and Brembo working o n carbo n fiber disc brakes (a sp in -off from th e Ferrari FI car project ) instead of th e a lready very light plasma-sprayed a lloy Zinzanis presently filled. A carbon-fiber monocoq ue would lose the lot in one go, but Thi el smiles ru efull y a t the thought. " We had a budget of$500.000 to go racing with in 1982," he says, " w h ich m ust be the biggest in the sm aller classes, but even we couldn' t afford that sort of technology-, Onl y car teams can !" So instead . he concentrates o n the art of th e p ossible, wringing in creasing fractions of a horsep ower from that amazing engine. The separate cylin ders are made by Hoeckle in Germany. as is the pressed-up cra n k which runs in four ball bearings. with needle roller bi g a n d little en ds. Great ca re is tak en no t to leave an y cylin ders lying a ro u n d within reach of prying eyes, but th ere ar e seven po rts in th e Gi lni sil bores (six transfer, .:..?!1~ ~e$p~~ ~!) , .i ~ ,~ ~!rh ,.~\:,.n ~ah le , 33 ..