Cycle News - Archive Issues - 1970's

With the dawn ing of the industrial age modern man coined a new language to explain the happenings of an organized and mechanized society. One of those terms was "The penalty of taking the lead," which in plain English means that he who leads now loses later. In th e world of racin g mo torcy cles the Czech osl ova kian CZ brand was the lead er in developing ligh tweigh t tw o-stroke m otocross bikes. They have been so succ essful that more m oto cr o ss champ io nship s had been earned on CZs th an any othe r brand . until the present j apanese d omination . CZ was the first. CZ was the best . but CZ is the last to ca tc h up to the su spen sio n revolution. Miraculously the small Eas tern European country produces the com ple te un it. every piece from tires to tools is m anufactured wi th Czech o m aterials. Remember how lon g it t ook th e e fficient j apanese to change from ru b ber foo t pegs an d wa ffle grips. well in th e bu reaucrati c tangles of red tape Czechoslova kia th e same de lays have co me about in susp en sion. To b ring abo u t the simplest mo difica tio n in a CZ mean s ap proval fro m lo wer Commiss ar to up per Co mmissar. becau se th e Chay-Zed is no t jus t a motorcycle ; it is a nati o nal stat us sy mbol. T he "Pen alty of ta kin g th e lea d " in mo t o cro ss mach in ery is a rel uctance t o re-t oo l, re-design , or re-organize . The Czech Motor Cycle Wo rks h as 40 years of motorcycle manufactu ring hist o ry and it was their proven desi gn that allowed th em to en ter the co m pet itive world of mo to cross 14 years ago an d rise to th e top . But sin ce their hey day of the late sixties and ea rly seventies their sa les have plu m meted t o th e botto m . While t im e may st and st ill in Pragu e it moves o n in Am erica an d that movem en t is n o w m easure d in terms of rear wh eel tr avel . In th e in terim CZ rel eased the Falta Replica . designed from J ar oslav Fal ta 's almo st World Championship winning m achine. but its accep tance has been poor. TI, e Falta rep lica ca me with alloy rims. lightweight ignition and air/o il sh o cks m oved fo rw ard on the sw inga rm . It was not enough for a fickled buying public th at had see n monoshocks , ca n tilevers, laydowns, rear forks , t orsion bars and numerous inde scribab le suspension ap par at us. The Falta Replica was to o lit tl e to o late and throwing in plastic fenders didn't help . No. it remains for the enterprising American market pl ace to breed its o wn CZ with a European heritage. This co m b in atio n of socialist-cap it alist oneness is found in the im macula te workshop of South Bay Moto rcycles in Redondo Beach. California. Cze ch Joe Kubicek runs So uth Bay and is more th an awa re of the problems associated with the CZ brand. yet knows that th e reliability (inde st ruct ability), broad power band. low cost. and goo d handlin g m ak e the CZ an excellent buy . Any CZ fro m 1970 to 19 75 ca n be made into a co m pet it ive racing mach ine o r easy riding pl ay bike under the skilled h an ds o f Joe Kub icek. In the dis posable ma chinery era o f modern motocross taking a six ye ar o ld motorcy cle or even a six month old motorcycle and making it not only competitive, but eye appealing is al most unhear d of. Un til now. The gang down at South Bay t ook a 1974 250 CZ red fr amer box stock o ut of the cra t e an d for a total price o f less than $1 ,295 turned it into a better ma chine than the exp ensive Falta Replica. The f rame The old red frame sin gle down-tube unit is stripped clean and placed in j igs, exact co p ies of the works center port jigs at the fact ory , a nd th e cu tting begins. When the grinding stops all th at remain s is the back bone and the rear engine cra d le . With high qu al ity chro me-moly and razor edged welding th e fram e is reb uilt to acco m moda te th e new exhaust port locat ion and lon g travel sus pe ns io n . Th e re ar frame loop is raised an in ch and o ne- ha lf for more fender clea ranc e..Up per shock mounts are posi tioned o n the to tall y new rear sub-frame an d th e newer model tubular swin g arm is bolted o n . A coa t of deep blue paint ca resses th e n ew ce n ter port / cantilever frame and the new suspension co m po n en ts are bolted on . T he rear ta kes a se t o f gas Girlings with 110 pound springs. while th e fro nt forks ar e d isassem bled an d th e da m per hol es m odified to improve th e feel. For in cre ased t ravel an air fo rk mo di ficati on will yield a h umper crop o f mo vemen t. CZ's o wn str on g hubs and go od bra kes are bracke ted inhe tween th e front and rear pivots with A kront rims a nd Ba rurn tires. As the 250 CZ sits . less its engine, it is strikingly simple and effective. The rear end modification, done with workmanship par ex cellence, provides a full eight and one-half inches of controlled travel. Gone forever will be the infamous CZ hop thanks to the beefier swing arm, increased frame rigidity, and long travel. The stocker front forks with damping mods provide only six in ches of t ra vel . A Terry Industries fork kit gave us seven , while air forks on a co m panio n's CZ are' plunging a full eight inches. The engine The 250 CZ mill has a repu ta t io n for be ing rugged, rel iable and torquey (read slow). Most CZS running to day have never had a top-end j o b unless they are over two ye ars o ld. The power is like a thermostat ; you just dial it on from low to high. The major modification to our engine was m ovin g the exhaust port fro m the right side of the cy lin der to the cen t er. This would seem to be a useless exercise if all th at it garnere d was a cleaner loo kin g profile, but th e repositioned exhaust port frees up th e scaven ging and circulation o f th e burnt and excess gases. A more efficien t ex hau st means a more effi cie n t intake and reciprocating system . The result is a horsepower in crease in the neighborhood of two to three hp . With the cen ter port exhaust releasing the gases South Bay turns to an improved JOK intake manifold and 34 m m Mikuni carb to get the gas in. The Mikuni on the South Bay CZ comes with a small white nylon dial on the float bo wl that co n tro ls an adjustable mainjet, Unlike the earl ier adjusta ble m ain jets this one is m anufa cture red by Mik uni a n d w as tested on snow mo bi les. lt allows jetting to be alt ere d in steps of t en jet sizes within o ne re volution. T he eng ine with it s Mikuni earb replacin g th e Czecho Jikov bol ts neatl y in to the modified fr ame and is mounted eve n more securely, on str o nge r mo tor mounts, th an st o ck. An im pressively tucked in and superbly crafte d do wn -p ipe is slip fit into the new exh aust port. The p ip e runs parallel to the frame tubes in a well pro tect ed lo cat ion be fo re exiting o n the left side behind th e foo tpeg and archi ng up war d at a 45 de gree angle. T he pipe is silenced m oderately . but the ba r k is quite lo ud. The handl ing May be it is ro mancing bac k to the go o d old days. but t he re is n o thing like a CZ . Off th e lin e nin e times out of t en . or ten ti mes out of t en . o ne of the hy per-po ten t J ap an ese machines will be at yo u to the firs t tum. But th e race isn It won in th e firs t tum, it is won a t the fin ish lin e and between those two points the CZ has quali t ies th at rank it ab ov e its japanese co mp etito rs in man y areas . The power delivery on the CZ is smooth. So sm oo th in fa ct that raking the gear shift lever isn't n ecessary and for every two shifts of a monoshock or RM the CZ only needs o n e. The five speed trans allo ws you to pick a co rn erin g gear, keep the throttle on and co me out o n the gas, while the more abru p t delivery of the Oriental Expresses results in a lot of wheel spin. Through the rough stuff the CZ track s straight. The new gas Girling rear end soaks up eigh t and one-half inches worth of terrain in a steady and predictable manner, The extremely light spring rate (11 0 lbs.] probably wou ld have to be upgraded to around 135 lbs, for heavier riders, or after the swing arm and shock mounts get sloppy from wear. The limiting factor of the rear suspension is the front. The front of our bike only had six in ches of travel and because o f this the rider t ook more jolts than necess ary. Fork travel can be gained in many ways, but we preferred the fine line co rn ering a f st andar d CZ geometry. Many times long travel for ks so radically change the geometry of the front end th at a former handler becomes a wash-out specialist. For serious racing in ·the Expert ranks ch anges would be necessary, but for the playbike rider and Sunday fun racer the bikes is right within its limitation. We trailrode the bike and we raced it . We mistreated it and we under·maintenanced it. We ran the same plug for four ra ces and cleaned the air cleaner haphazardly. We crashed it and we won a little gold on it . but it never failed to start, run cle an, give us a good time or protect us when we go t in too deep. This is th e bike for the budget racer, the man who races for the sheer joy of racin g o r the guy/gal who wants a sweet hand ling hit-it-with-a-car-wash and gas-it-up machine. • Where, what and how much Center port engine $ 90.00 Center port frame $110.00 Center port p ipe $ 49.00 Rear Suspens ion $110.00 Gas Girl ings/springs , . , ... .... . . • . .... .. .. $ 89.00 34mm Mik uni ki t $ 69.95 Air/spring fork ki t . . , . .. . .. . • .. . . . . . . .. .. $ 45.00 Co mplete package less 25% Sout h Bay Motorcycles, 2001 Artesia Blvd ., Redondo Beach, Calif. 90278. (21 3) 772-1647 27 .,

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