Cycle News - Archive Issues - 1970's

Let's Go to the Hop, Oh CZ ! ,... N . :; ~ w Z W -J U >- U b y John Huerter Not too many cons ago, Cycle News West had an article on how to cure the "Husky Hop:' which a lot of the Swe dis h ma chine's riders co mp lain of. The secret 0 f doggy happiness wa s leng thenin g th e swingarm righ t behind the frame pi vot poin t, Now, it is alm ost gospel among th e true b elie vers in off-ro ad motorcy cling th a t ano ther make machine has an even mo re p ron ounced tendency t o hop fr o m side t o side o ver whoop-de-does, rip ples, b um ps , etc. When ever anybody can 't th ink of anything .else to criticize about th e handling of a CZ (And let's face it , there's little com plaint about th e Cze ch's maneuverability rna nners .] , they come up w ith the cle ver observation that the re ar en d hops from side t o side . "Get rid of those j un k Commie shocks!" goes up th e cry. S o th e intrepid CZ rider puts o n so me proprietary brand of sh oc k abs o rbers and th e rear end sti ll hops from side to side. " Gee , m aybe it isn 't the shocks," the rare th ough t ful rid ers muses. (The o riginals aren' t that bad in d esign ; just sprung to o hard fo r m ost ligh tw eigh t MXers p lus th e -dampin g fluid ain ' t the best, Czech pe tro leum products being what they arc .) So o ur wo uld -be hero ch ar ges off to th e racing wars on a bike th at is d ep endabl e, goes very fast in stock tri m, has fo rgiving hand ling an d hops from side to side. ANSWER THE MAI DEN'S PLEE Now Cycle Products West (n o releation - to this newspaper), a very ente rp ris ing accesso ry shop in West Los Angeles, is alway s lo oking for tric k go odies t o improve the handling, power output or appearan ce of a racin g mot o rcy cle . T he quic k an d simple so lution to C Z rear end h op that w as devised, af ter cutting up a couple of perfec tly in noce n t CZ swing arms, was to ad d an inc h behind th e sh ock m o un ting p o in ts an d rei nforce the swi nga rm top an d bottom around the chain adjuster/axle slot. The mild steel extension blank is welded ,by tu ngsten in ert gas me th od ch an ges, The 400 CZ carried a 13 to oth co un te rshaft sp ro cket. It did no t require an y additio nal chain links. A cross op en ground i t w as immediately apparen t th a t the front wh eel was not go ing to come up as eas ily as it h ad in it s sto ck conditio n . The major p roblem in lo ftin g th e wheel w as avoiding wh eelsp in , as weigh t transfer did not seem to b e as prono unced. This was not a prob lem, except in whoop-de-does, where the fro nt wheel liked to sma ck in to the next wh o op unless car eful attention was paid to setting up the bike's a ttitude. CZs seem to slide pretty w ell in their stock state , but with the swingarm Before yo u start cutting and weld ing on the 5winlsrm. It' s a lot more san itary if you ta ke it off yo ur b ike first. The sw ingarm shaft tends t o dry ou t a nd get sticky- ru sty so a little pe ~suas io~ . with W0-40 or the like helps. Be wry careful not to mushroom the end of the shaft bangIng on It or strip t he threads inside t he s ha ft w ith your drift pin a nd ma llet . ... ~,......-~----- be tween the cut off flat tab an d th e round p art of th e swingarm, th en ground off to a smooth finis h. Then you pu t th e swingarm b ack on an d yo ur CZ wo n't h op fro m side to sid e anymo re , righ t ? A ny way, that's the story. We decid ed t o fin d out h ow much of an impr ov em ent th e 535 wh eelb ase ext ensio n ac tu ally made in th e h andling. Ri ght off you ca n sec th at it should track straigh te r in o ne direction and that more wei ght will be o n the front wh eel. It should slide better and stic k in co mers with ou t w ashing out a t all . It sh ould be more di ffi cult to lo ft th e fro nt wheel; th e frond end won't come up as quic kly when you wick th e 250 or 400 models. TH E PROO F IS IN THE RIDING Clean th e munge off your sw ingarm and send it to Cyde Products West lun less you have 8 hell -are torch ), The first th ing they do is open the package and see if vour check is going to bou nce . Then t hey straighten it in a CZ·unique swingarm jig which will also be used for cutting a nd plac ing th e extension tab. You'd be su rprised how many swinga rms get tweaked . Th e ex tension pla tes alone cost $10. Ridin g th e r e- swingarm ed CZ requ i r ed a n atte m pt t o put precon ceptions out o f your mind. Whil e valiant efforts were made to d o so, th e modification seem ed to produce j ust about th e re sul ts e xpected. With th e wh eelb ase sligh tly exte nde d and th e weight distribution moved tow ard the front wheel, th ere were so me no ticeab le eET READY FOR THE '73 TRANS· AMA & PRO MI RACES WITH YOUR PRO.AM MI SHIRTS PEN SERIES TON Compliment s of Pent on W est M cr,ILL CYC PAR LE K It's a must that you have a name and numbe r for all PRO A MA RACES • 1 s 12.95 eo(h FEATURES: Nylon vented .. padded elbows .. weighs less than 6 oz. Shirt comes with name and number on back and name of bike on front. 11 .0 . nr ( 'I-:IIT'II nllTI\ In: 11011I_11 SI~OIlTS I' 110 1ll ·I ·TS. I",'. 'HR. nf "110 - ."1 Prnduct s . lIiRh land &: IIh il" Sis , 1 ~ '! 1l (. n ·('f1~I.I n.: . SIZ E : I ) P enn a . 11(10 1 S ( I II ( i L ( I :\L Send your name, bike and number ('01.011 : lsi {'hnic,, 2n d c ho in . I 1 I ~---------I ....- - - - - - - 1 PL EASE SEND ME_PRD - AM M,X. SHIRTS I PEALERS AND PISTRIBU- NAME ' • I TORS CALL (412) 836-1302 AODR ESS I CITY STATE •••••• • • • • • ~~- - - - - - - - ZIP_ _ ex tended s li d in g was i m prove d n o ticeabl y . Un less an incredible blunde r was pulled, the rear end would just no t lead the fro nt. T he bi ke was very stable an d predic tab le. It would even slide nicely wi th power off go ing into a co rner. All th is w as ob tain ed while maintain in g n ice turnin g quali ti es. It still stee red j us t fine. For scram b les or smoo th track it w o uld see m to be th e ticket. In wash board or wh oop-de-d oo s, th e o ld CZ h op trick w as tam ed somewh at. The rear end st ill kicked aro und but th ere w as n oticeabl e imp ro veme n t. Mo st of th e improvement w as in reduction of side- to-side b oun ce. One thing th a t became read ily ap p are n t wa s th at th e weight di stribu ti on chan ge was eno ugh to merit a sp rin g ch an ge o n th e shocks . T he rear end kick ed straig ht-u p. On the 400, with a 170 p ound ride r, it would mean ch an gin g fr om 60-90 progressive to m aybe a 70 p ound sp ring. For smooth er motocr oss co urses o r dirt track, the swi ng arm modification s h o uld be real fin e. For cob by moto cross or desert whoop-de- doos it mi gh t no t b e. I eryinner s ~o to Cross (Beginners, . Junio rs or N ce Only) ovi R $3,000.00 i n Prizes Includinq a Penton for E ach C ass l Overal l Winner. Pri zes to Top 10 in Each Class 15 Troph ies Per Class Check Rike Shops For Entries N Amateurs - E xpe~ienced Seniors o Si lencers Required - No Pit Ridina YAMAHA MINI ET-MX FREE (From C & R Yamaha) To One Luc ky Spec tator (Mu st Be Present - May 27 to Win) ~ail Entries $~.OO - Post $R.OO Spectators & Over Night CaMPing $2.00 - (Under 12 FREE) Aoril 15 Moto Cross - Mail Entries Close April 10 April 29 Moto Cross - ~ail Entries Close April 24 May 13 Moto Cross - M l Entries Close May 8 ai M 27 H Scrambles - Ma il Entries . Close May 22 ay are MC C Lice nse Requi red C C Appli cati ons & Entry Forms A M vaili abl e &A ccept ed A t ~c r, i l l C ycl e Park - 13300 W t e R hi ock Road - R ancho Cordova , C 95670 a Ca11 351 -0271 SACRA~ EN TO 'S n ~LY FA LY CYCLE PARK OFFERIN~ DAY RID IN D ILY MI r, A

• Cover