Cycle News - Archive Issues - 1990's

that's becaus e you' re tak ing them with the power off. Exit said chicane too en th usiastically in terms of taki ng a big handful of throttle to get an ear ly drive ou t, and' th e massive wheelie which can all too easi ly thrill onlookers whi le giving the rider heart failure if he's no t prepared for it is a further ' indication of the lack of weight on the from wheel - as well as the amazing torq ue and impressive pow er of the rotary engi ne. .• Interestingly, in spite of th e su bstan tial sto p ping power afforded by th e cast- iron PVM discs and the ir AP calipers wh ich have reall y improved th Norton' s brak ing performan ce over its air-coo led predecessors, it's ni gh on impossib le to get th e back whee l . wavin g in th e air as is all too common place on the current breed of G P bikes, further indica ting a rearward weigh t bias possibl y affect ing th e Norton 's handling. T his readiness to wash out the front win ding the revs up to get back in the powerban d - doesn 't work wit h th e ro tary, whi ch refuses to pi ck up ana ru n clea nly aga in till you go th ro ugh the time-wasting process of notching down a gear, closing th e throttle and practically sta rti ng all over agai n. For this rea son , ri ding a rotary racer reasonably rapidly requires a really radica l technique and pretty intense co mm itment , revs to get it round corners properly - but then when you do that, welco me to the wonderful wor ld of power understeer thanks to tha t lack of front end weigh t and the. inadequate rear suspensio n design. A cu rrent 500cc V4 GP bike like the Yamaha or Cag iva is easier to dr ive through turns tha n the No rto n , in spite of the rotary's mil e-wide power band and flat torque cu rve which the · chassis fa ils to u se to ma x imum advantage. And wide and flat respectively th ey certainly are, with the RCW motor The author found the RCW588's acceleration to be "awe-inspiring." He was less complimentary about the five-speed gearbox, calling it "plain awful." At!i claimed 341 pou nds, the Norton water-coo led RCW588 is 22 pounds heavier than its air-cooled p redecessor. end wouldn 't ordinarily be so much of a problem were it not for th e unique nat ure of the rotary engine, which demands to be ridden with th e power han d on or practically off in turns you just can' t ru sh into a corn er like Cora m or Riches and scrub off speed on th e way in before gradually open ing die throttle to feed in the power as th e trac k opens up again on the exi t, because the rotary's traditional dislike of part throttle openings is especiall y noticeable on the RCW: the others I've ridden su ffered from this too , but not as badly as th is bik e. It has the same char acteristics as a bike fiued with car type mechanical (not electro n ic) fuel injection, wh ich is designed to work properly only at full throttle: try to avail youself of the ro tary 's undoubted flexibility by progressivel y winding open the twis tgrip, and th e engine will start to misfire and hunt like a fourstroke with megaphonitis or a two stro ke being ridden off the pipe. However, the traditional means of dealing wiht these two problems taki ng a big handful of clutch and firing in a coup le of step s as easi ly as a two-strok e thanks to the low 9-2-1 com pression, before settling to a fast id ling burble which at pea k rev s cha nges to a un ique shrieking exha ust not e hal fwa y between a J apanese su perb ike a nd a VIO Renau lt F-I engine. In sp ite ofm ore radi cal po rting on the perip hera l po rts which is one of the secrets to competi tive rotary power, the RCW still behaves like an electric motor, pulling from 2000 rpm with out sli p pi ng the cl u tch a n d bu ilding powe r and revs with im pressive speed up to the 11,700 rp m redl ine at which the rev-li m iter is set to cu t in on one cylinder via th e hall-effect . CD! ignition. In practi ce, you never need to rev it this hi gh , since pea k power (decla red at 140 bh p at th e gearbox in cu rrent guise, though over ISO bh p has certain ly been on tap a t on e sta ge and may still be for all we and the FIM decision-makers know ) is obta ined at 10,500 rpm, with maximu m torque a t 8000 revs. However, the bike seemed happiest if revved to 11 ,000 rpm in th e gear s, since the widel y-spread rat ios of th e ro adderived gearb ox. whose an cestr y lies deep in the Triumph hi story books and th is lacks an y capaci ty to cha nge intern al gea ring mil itat e in favor of doing so. T he Norton 's acceleration is truly awe-inspi ri ng in spi te of the rather high decla red weight of 341 lb. in cu rrent form - curious when one considers th at the last ai r-cooled bike scaled 319 lb. and tha t the prin cipal reaso n for go ing to water-coo ling for th e 1989 seaso n was to save weight th anks to th e el im i n ation o f th e massive, and heavy, finning of th e older motor. The RCW broadl y feels to have the performan ce of a two-year old 500ec V4, wi th th e important di ffere nce ' that the step less p ow er del ivery and vast powerband make it far easier to con tro l the outp ut via th e rear tire, without any sudden surges in del ivery liabl e to unhook the rear end such as even th e most progressive po wer-valve system on a V4 two- stroke w ill in evitab ly offer. Th e la rgediameter flywh eel fitted to the left end of the rotor shaft tames some - but not a lii .- of the huge amount of bouorn end torque, making it easier . to exi t slow corners like the Esses wi tho u t looping th e loop once you real ize th is is a serio us possibility wi th the front-en d happy chass is and massively torq uey engi ne, wh ile revvying the bike to 11 ,000 in the gea rs rat her tha n short-shi fting to keep the front wheel on the' ground as you might on a GP two-stroke preve nts wheel ies in the intermediate gears which the bike is othe rw ise quite prone to pulling. A trai t the rotary does share wi th the 500 cla n of today is straight line instability when you h it a ridge of bump in the road surface: what happens with the Norton is . that th e front wheel pops up in the air and the bike starts to shi mmy when it touches do wn again, even with the steering damper done up two notches from max - any more, an d you'd never get round Symmo ns Folly witho u t mak in g a thr ee-point tu rn . An d there's n o reverse gear filled . ',' Ah yes - the gearbo x. Well, there's no ign oring th is an d no way to be polite abo u t saying it: the 5-speed transmission with its duplex chain primary driv e fiued to th e RCW is just plain awf u l, and that 's the honest tr uth, as is the fact th at a gearbox design ed to cope with not much more than 50 bhp in Triumph road form should not be expected to take almost three times th at ou tp u t without problems . As filled to th e pr evious rotary racers I've sampled the cha nge was always slow and it was impossible to come down th e gea rs two or more at a time as you would want to do wi th an engine that is happiest under pow er so that it demands to be ridden two stroke-style, All that is still true. - try to hurry the cha nge and it'll baulk, espec ia ll y on a downward ch ange which may well, ahem, leave you sailing into a corne r in an unwa n ted neutral, trying desperat ely to find a gear while a t th e same tim e fending off th e encroaching tire wall. But now the upward change is almos t as bad and very awkward, becau se Norton engineers have obviously had to und ercut the dogs so greatly to avoi d the gearb ox j um ping ou t of gear thanks to th e hefty .in crease in power ou tp ut that the result is a notchy, har sh and mechanical change th at practicall y requ ires you to lift your left foot off the rest in order to hoi ck it into th e next gear higher. Sometimes th e change is so stiff in either direction th at it seems for a moment as if it's stuck in gear - but no, you just need to practically kick it and it will change, after all. Eventu ally. By this time you 'r e either bouncing th e rev-limiter or about to 15

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