Cycle News - Archive Issues - 1990's

Aaron S light's CastrolHonda RC45 - - - --- -- - - - - - - - - - - - - - - Ohlins tech nician An ders And ersson worked well from the very start, giving Rumi riders Crafar and Brian Morrison a good-handling package that partially offset the problems with the power delivery . Riding Slight's Cas trol RC45 at seaso n 's e n d u nd e rli n ed th e difference bet ween a works racer and a cus tomer bike, however well-p repared - a d ifference that with the coming of fuel injection and the electronic era can only intensify, be cau se the factory ho ld s th e key to development in the form of the computer access codes to the EFI software - which you need to change to take full advantage o f an y mec ha nical improve me n ts o r en gine tuning . One lap on th e work s RC45 is enough to tell you that HRC has Aaron Slight rode the Castrol Honda RC45 to third in the World Superbike Champ io nsh ip in 1994. Contributor Alan Cathcart tested the bike in Jap an. By Alan Cathcart Photos by Koichi Ohtani ft er lo ok in g at th e fin al p oint sta n d ings fro m th e 1994 World Superb ike Ch ampion shi p, yo u' d expect Honda wou ld b e pleased with th e d ebut year of it s fue linje cted RC45 . New Zeala n der Aaron Sligh t was in with a chance of winning the title right up to the final round in Australia, and he ended the season third overall after an u ltra-consistent season which saw him score points in every race with the excep tion of a crash in Germany, and the fam ou s d isqu alification in th e first round in Britain (when Honda's fuel suppliers, Elf, admitted to having misunderstood the new FIM fuel regulations for the Superbike class introduced this season). That aside, Slight .still wou ldn' t have \"on th e championship, but he w ou ld have been second overall and a lot closer to eventual World Champion Carl Fogarty - and all withou t winning a sing le race all season. But eigh t second places in 22 races says a lot for the Kiwi's consistency, and with teammate D oug Polen fourth in the championshi p, and Simo n Crafar fifth an d top priv at eer on th e Rum i RC45, ' Honda would have reason to be satisfied w ith th e debut se ason of their all -new Superbike - espe cially as Slight and Polen won the single most im portan t race on Honda's four-stroke calendar, the Suzuka 8-Hour. But this was the only time all season that the Honda won a race against topclass op positio n: Though teen ge nius An thony Gob ert w on th e Aust ra lia n Su perb ike title on h is RC45, th e new Honda only filled th e grids elsewhe re, leading many to assume that Slight' s and Gobert's su ccesses owed mor e to rider ability tha n .ma ch ine excelle n ce. Even Honda would almost certainly adm it that the RC45 failed to live up to expectations in its debut season - ex pectations th at might not normally have been so high, had a) this been any other company than the Big H an d b) H onda had not held back its launch by one year in a presumed R 32 effort to make sure it was a race-winner right from the start. .The chance to test Aaron Slight's bike at the Suzu ka Circuit a few weeks after the last round of the '94 World Superbike series in Au stralia was even more interesting than usu al, since halfway throu gh the season I'd already ridden Simon Crafar' s' priva teer RC45 at Zeltw eg . The Rurni bike was fitted with Ohlins suspensio n an d th e sub ject of some d eta iled engi ne development by the Rumi team, which had raised the p ower outp ut from 138 bhp at the gearbox (when de livered and fitted with HRC kit parts ), to 147 bh p on the Rumi dy no - a power increase that was very grudgingly delivered . If not quite as powerful. as necessary or expected, this wasn't the main problem when I rode the bike: Competitive pow er was only delivered at the very top end, making it necessary to rid e the RC45 like a GP two-stroke., flirting with th every aggressive 14,100 rp m re v-limiter and using the six-speed gearbox hard to stay out of a massive flat spot between 11,00011,600 rpm. Not an easy bike to ride, even by mod ern Superbike standards, and one that lacked acceleration when sta cke d against a works Duca ti 955 on the track at the same time. But the Ohlins suspension - 'w ith a n e w rear link d ev el oped b y done a lot of work on improvin g th e pow er d elivery: The dread ed midrange flat spo t has been removed (ma in ly by altering the electronics, according to HRC engi neers, but also with the help of a differe n t exh aus t d esi gn a nd camshafts / valve timing ), SO that the bike now pulls cleanly from 8000 rpm out of a slow turn like the Suz u ka hairpin or chicane, and run s on thro ug h witho ut a hiccup up to 14,OOO-plus rpm. The rev-limiter has been moved higher up the rev-sca le to 14,500 rpm and is also less emp hatic, so that it only flutters the engi ne, ra ther th an killing it stone dea d and losing you 1000 revs before it cuts in aga in. The purpose of this is to let you rev it to 14,200-14,300 on erich gear change to max out the po wer delivery - it flattens ou t above 14,000, and d oesn' t keep pulling like Scott Russell's Kawasaki d oe s a ll the way to you r 14,700 rpm appoint ment with its rev-lim iter. But at least now the Honda has a more torquey mid range - presumably thanks to those special camsh afts - an d is easier and more forgiving to rid e in terms of the power delivery, even if it still lacks midrange punch, and acceleration. How so sure? Because just by chance the wo rks Kawasaki Japan ese champions hi p team was testing at Suzuka the sa me day tha t I was, and I tw ice got zapped by their bikes in a straight line, once out of the Spoon Cu rve an d th e other time past the pits - both times exiting s lo w turns an d a ccel er ating up through the gea rs. Since even a preten d Su perbike ra cer like me ca n twist th e wrist wide open in a straight line, the fact tha t bo th times the Kawasaki wou ld get a jump on th e Ho nda abou t 220 y ards onwa rd fro m the exit illustrat ed w h at Aaron Slight has had to pu t up with all year long. It takes a brave man to sling it through turns as ha rd as you need to do to pu ll back at least some of that disadvantag e, and thoug h the gritty Kiwi's de termined ridi ng ha s been a highligh t of the 1994 Superb ike se aso n, th e re ' s a limit to human ability to compensa te for mechanical defi cien cy, es p ecially if you keep th r ash in g the tires in doing so. The Ho nda actually carburets better than the Kawasaki low down, so that the in iti al jump out of the turn isn' t wh ere you lose out - it's once you're in to third or fourth gea r and about to hit fifth that the superio r p ow er of th e g reen bike tell s. Top speed is the same, as proved by Slight's 181-mph trap speed at Hockenheim, the same as the works Ducati and Kawasak i it's just getting there that's the problem . The Cas trol Honda team saw 143 bhp a t 14,000 rpm a t th e rea r w heel on a Dynojet brake, which means they're 5-7 bhp short of the op pos ition on top end, too. It shows that Honda has the aerodynamics rig ht , at least. But the secre t to trul y co mpetitive hor sepower is su rely locked up in the PGM-FL fuel-injecti on ma pp ing, and just as Bimota and Du cati foun d back in 1987/ 88 when they introduced EFt to the wo rld of mo torcycling, it takes time to perfect that. But the RC45's fuel injection already delivers a ran ge of benefits over carbs, notably the immediate th rot tle resp onse which can be a bit disconcert ing if you' re not already used to it thanks to racing a Ducati, and the improved fu el co ns u m p tio n through more precise metering. This was the key factor in Honda's crucial victory in the Su zuka 8-Hou r when th e RC4 5 came good. The Kawasak i was faster in sprint form for qualifying - as proved to me on the same track during my test - but had to be leaned off to reduce fuel consumption so it wo uld go the distance betwee n stops (as well as revved lower for im p roved reliability). The fuel-injected Honda was less thirsty, so the two bikes ended up equal on performan ce and Aar on Slight got the better of Russe ll in their head -tohead battle for victory. That Suzuka race was the only time Slight rode the RC45 all season with the 25mm lon ger sw ingarm which Ho nda introduced soon after the start of the seaso n, and whic h H RC had fitt ed to the bike for my test. Othe rwise he used the standard -length sing le-sided swi ngarm, with extra bracing added by HRC, to try to make the bike handle qu icker in corners. But I fou nd Slight's machine still h ad the sa me pow er-und ersteer ou t of tu rns that the prototype RC45 Superbike I rod e a t Su zu ka a ye ar a go had - but which was absent on the Rumi bike, w ith its Ohlins sus p ens ion and alt ered rear link, but otherwise near-stock geometry. Accelerati ng ou t of the Spoon Curve or at the top of the hill behind the Suzuka '

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