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Issue link: https://magazine.cyclenews.com/i/128599
Colin Edwards' Castrol Honda RC45 (Left) Honda switched brakes in 1999, opting for Nlssins rather than the Brembos the team had used In the past. (Above) Honda fitted a 15mm-thlck plate between the crankcase lowers and the 011 sump. essentially getting the benefits of a drysump system. admitted that the RC4S's fuel system was changed for '99, with a variablepressure supply instead of the hjgh four-bar constant pressure of before. Now there's a lower, two-bar pressure at low rpm, which helps improve fueling by lengthening injection timing, giving a better mixture and improved cylinder filling and thus better combustion for a crisper pickup, before switching to the higher four-bar pressure at high revs. There are still two injectors per cylinder, firing together - Honda's experiments with sequential injection haven't yet produced the required results, so there's just a big, single, coordinated squirt. But the net result is awesome acceleration, yet delivered so controllably that you relish taking a big handful of throttle and watching the tach's needle scoot around the dial to a zone no other Superbike can currently match. Magic. The other big area of improvement over last season was the Showa suspension - although Honda continued experimenting with different frame gussets to promote controlled chassis flex, for more feel, as well as a new asymmetric double-sided swingarm that both riders jettisoned in favor of the Type 6 version used in '98. Although externally the same as in '98, the Showa shock and 47mm inverted forks have been comprehensively revalved for improved compliance. The rear shock now has a double external reservoir for a less harsh response, and it felt much more con- 16 FEBRUARY 9,2000' cue trolled over the few ripples in the Motegi surface than the less sophisticated setup in the RCS1 V-twin prototype I was riding the same day. The biggest improvement, however, is up front, where the twin external reservoirs also found on the fork increase its air capacity and give scope for ready external adjustment for fine suspension turung. However, the biggest difference was Edwards' cure for the uncertain front-end response that plagued him throughout his first year with Honda in '98. "We had a real problem with weight transfer," Edwards said, "where you'd brake into the tum and instead of just stopping on the front, it'd keep going, then bounce back on you. That meant you had to steer it on the throttle because that's where the weight was, plus the front end would suddenly get light because of weight transfer, and you'd lose grip and fold the front wheel. I crashed twice in the same tum at Sugo in '98, and that's when we realized we had a problem with the fork, not at the rear end as we'd figured previously. We revalved the forks over the winter, and since then the bike's been awesome." What the team did was alter the check valve in the fork to better control the transition from compression to rebound, and when you start trailbraking deep into a turn on the RC4S, you notice the difference when you let off the brakes, especially if you're trying to keep up cornering speed • e n e _ 50 and are pushing the front a little to do so. There's not only improved front-end feel, but it feels a lot more balanced, with reduced weight transfer as well. This means the Honda holds a line better and gives you more confidence in getting hard on the gas for a good drive out of the turn. I also felt much more confident on it this year because it was set up for Edwards - as opposed to Aaron Slight or, before that, John Kocinski. I know from riding his factory Yamaha Superbikes in the past that Edwards' setup is very much to my taste, with a pronounced but not excessive front-end bias thanks to a raised rear ride height and steering geometry that aims at a happy compromise between stability in fast turns and turning easily in slow ones. It feels right. Also right for '99 was the biggest single change in componentry on the Castrol RC4S, with the switch away from Brembo's troublesome new four-piston radial calipers to Nissin six-piston ones. The Nissins are exceptional for its sheer stopping power and the progressive feel it delivers, especially when combined with the worthwhile engine braking available via the slipper clutch, even with the reduced inertia of the latest V-four engine. Thanks to his more aggressive riding style on the brakes, Slight suffered most from the Brembos sticking on - though Edwards also fell a couple of times because of this - so he was happy to swap to the Nissins. "Even the two-piece Nissins dragged occasionally, but not as bad as their rivals," says Edwards. "It didn't happen to me, so I obviously wasn't squeezing hard enough." The thing that impressed me most was how stable the Honda was braking hard and deep into a demanding turn, like the downhill right-hander at the end of the Motegi main straight. After I was finally persuaded off of the track with the RC4S, it dawned on me that I may have been the last person to ride the last of the V -four Honda line, and I think this is a tragedy. While the RC4S did take some time to sort out, it did achieve Honda's aim of winning the World Superbike title - and all those endurance races, including the 8 Hours. If Suzuki or Kawasaki, let alone Aprilia or any European company, had developed a superbike to this level of competitiveness, the last thing they'd be thinking of doing now would be sending it to the corporate museum. To replace the RC4S, Honda has instead developed a 90-degree Vtwin, in a move that, however successful the RCS1/SP-1 may turn out to be, many will still regard as a retrograde step. Why so? Well, Honda's engineering policy throughout the company's SO years of exjstence, say the critics, has always been to do things differently - to do it the Honda way. In racing terms, that meant a glorious succession of unigue fourstroke GP bikes throughout the 1960s, when almost all others used two-strokes - and in any case, nobody else bujlt five- and six-cylinder GP racers, or SOcc DOCH twins, only Honda. Who else but Honda could ever have built the oval-piston NRSOO, forerunner of the range of round-piston V-four racers now set for the history books? And who else could have won the SOOcc World title for the first time with a V-three twostroke triple against everyone else's fours? Or to follow up with the only single-crank SOOcc V-four, when everyone else uses twin-crank designs? The Honda way is to do things differently a,nd to do them right, and on that basis I'll side with those who say that it's a great pity the next Honda Superbike for the new millennium isn't a state-of-the-art Evo V-four, rather than a V-twin that can only ever aim at being a better Ducati. My ride on Edwards' RC4S marked not only the end of an era, but it was also an indictment of the current World Superbike regulations. Honda is in business to win races and titles, and to allow their customers to do the same. If they've decided that the Superbike rules are so indelibly rigged in favor of 1000cc V-twins that they have to bujld one itself and so deprive race fans around the world of a key ingredient of the rich variety in a Superbike grid, then that's a real pity. Five years from now, or however long it ta~es, when superbike races are packed with V-twins, whether built in Italy, Japan, Australia or the USA, mark my words: We'll think back to the 1999 race season and recall the distinctive, droning exhaust note of the last of the V-four line with justifiable nostalgia - and I'll remember with pleasure the finest superb ike I rode in that era. Pass the Kleenex, Colin. CN