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/126249
C1 9n A J R E ~OL D S ' OB"'C C O C O DAYTONA 200 Suzuki got part way toward building a full-flo ating rear brake on jhe RM models . T here 's a m ounting bracket on the fra m e 'of most bik es and a floating bu shing in the re ar brake backing plate. C ycle Products W est has devised a full -floating rear brak e sta y arm th at com es with a weld-on bra cket in case yo u r lat er se ria l number RM doesn 't have the bracket. Does thi s m od sto p re ar wheel hop under hcavy braking? You bet it does. This tendency wasn 't that bad in the RM to sta rt with . The full -floating rear brake reduces it to near zero: It 's ver y confidence -inspiring. Why didn't thcy do it at the fa ctory? The ad ded stress could elo nga te the hole in -the tab of the light magnesium backing plate. piming ,it out of-round or even cra cking it. Ch eck you rs '~egu l a rl y if you g 9 for the mod ification. end , It ha s th e effect of extending th e . fierce mid-range ru sh and overc om ing the slig h t flatt ening of pow er encoun te re d at the top of eac h gear: It was a pleasant su rp rise to fin d th e RM ea sie-r to ride- even though it wa s. of all things . faster . T here- was still much , , low end - it just d idn't crack th e bike side ways o r loo p it when you opened the- th rottl e . I t we nt fo rward qu ickl y. T ho rwa ldso n a lso fig u re-d .he co u ld smoo t h o u t th e e nti re po werband wit h a more flexible reed o r th e crankcase induc t ion ree d valve. As he pu t it . "T he t hi'nner th e ree-d . the bette r th e pow e r t r a n sit ion . espec ia lly whe n th e 250 ca me on . I t ried a .0 14" th ick reed b ut fig ured yo u' d have to re-p lan' it every m onth . A reed pet al .0 17" thi ck worked a bo ut as well a nd sho u ld last indefin itely ." The reed pet als a re m ade of phenol it: material. " I had a bagful sta m ped .U L " he sa id . So far . all mods apply to both t he 250 a nd 370 RM s, Final 'lt ra -fine ca rb tuning on th e RM calls o r a Q6 needle jet. a 310 main jet and ,0 pi lot jet in th e Mikuni , a nd an FG6 eedle with th e spri ng slo tted on e ot ch do wn fro m th e mi ddle position . uz uki has a ll th e necessa ry carb efinernenr s a va ila b le . They have el·l·nt ly go ne sto ne se rious abo u t iro d uc tion racing. No w. if th ey would n ly m ak e t he RM q uie ter . . . • When the standard IRC tires on th e RM 370 got a littl e' worn . it was a handling ' p lus to repla ce them with Metz el cr s fo r gen erally .d ry, ha rd West e rn tr a ck s . Trell e bo rgs : o r Barums sho uld do it for those swell so ft . loam y, muddy circu its of o ur dreams. Steering of th e front end was improved with . the su pe r io r tire . Su zukis with Bridgestone kn obb ies seem to go just fin e with the stoc k ' .ru bber . Some have it : som e don 't . If you -stick yo ur loosel y cle nc he d hands ou t in front of yo u with your eyes closed . )'ou are likel y to di scover ' - rhey end up 3 1-33 in ch es a pa rt. That is o bviously a natural pl ac e for th em 10 be when yo u' re riding and ra cing . The RM 's handl eb ars are 35 in ch es-wide . One inch carrie off each end . . The sta nda rd Ka yabas work, very well o n th e RM 370 for about 15-20 minut es und er _ co rn p et it io n co nd it ions . It wou ld be nice to bounce around on some damper s that work ed ve-ry well for lon ger th an th at . Sa y, a minimum o f 45 m inutes on up to a couple of hou rs, To that end . we prevailed on Curnutt . S&W . T he Motocross Fox , Mu lholland and Works Performance 10 m ake ava ilabl e a pair of th eir own shoc k's for th e RM . with wh at ev er t hc y de emed to b e a ppro pr iate springi ng , We're. st ill. not re all y clea r o n why the Ka yaba gas shoc ks do fade awav o n th e 370 . nor a re so me- mu ch ' bette r. qu al ifi ed sus pe nsio n engi nee rs. The results of running th e RM with th e a bo vem ent io ned d ampers (T he o nly o nes we're awa re of besid es Kav a ba in nom in a] 15. 2 5 " length s.') we r e reve ale d fo r a ll the m ot orcycl in g world to see some ti me bac k in T he Great Am eri can Shoc k Test. _ Di d we have o ne ultra -fin e ha ndl ing . fas t , tractable Suzu ki-b u ilt m otorcycl e for racing around o n d in y courses? You kn ow it. Of course. th e m a c h ine is proba p ly beyon d t h e ca pabi lities of a l~ bu t a ha nd fu l of riders to usc il fu llv bu t th er e is some t hi ng indefi nab ly s\vd l a bou t roc kct in g a ro u n d Lo c al Yok el Ra cewa y o n a m a ch ine that m ost Grand Pri x ri de rs would be del ighted to ha v,:. For m ost of us. we're into a situ a tio n wh ere yo u have no exc uses in the m ach in er y. About th e. on ly th ing th at will "eel' you out of th e top three on an RM od 370 .is a flat tire o r running out of pre-mix . Where to get help: Cycle Product s West . 11900 Pico Blvd.• vyest Los Ang eles. CA. ' Thor Enterprises. 6895-H Oslo Circle. Buena Park. CA. Works Per for manc e, 20970 Kna pp St ., Chatsworth , CA. DAYTONA INT...·SPEEDWAY ·MARCH 13 1:00PM TH'E BIG BIKES ARE COMING ! And along wi th the Ame rican Motorcycle Associau ons high sp eed two wheelers- the ci rcuit's top and touqh est rid ers. The record breakers . The big boys. See 'em eat up the track , while they compete for cyc hnq's heavy prize money. Y 'll want to ou eaten all the ac tion from the first flag on. So come on out-early! . ' TICKET INFORMATION: Tic kets availab le at Daytona Ticket Omce. P. O. Drawer S. Daytona Bea ch, Fla. 3-20i5, For furthe r information ca ll (904) 255 ·53 01. Discover oneofa kind. Camel Filters and MotorcYcle: Racing. ~' . ~ ~ "',' ~~ NECA EL PRO-SE IES 19 mg,"tar", 1.2 mg. nlcotrne . 3lf. per clgarene. FTC R epon D C '76. E. Warning :'The Surgeon General Has Det;rmined' That C igarette Smoking Is Dangerous to Your Health. 17