Cycle News - Archive Issues - 1990's

_ - - - - - - = - - - - - - - - - - - " - - - - " - - - ' - - - -_ _ adds substantially to the overall stiffness of this vital area. The swingarm also is all-new (now with the Bimota emblem stamped into the flanks - a nice touch), again much stiffer than before, thanks to a different construction. But even though it's also 10mm longer than before, the weight distribution is unaltered, thanks to the bigger radiator and twin fans now fitted, as well as the substitution of the twin ba tteries in the nose of the bike (where you had to practically dismantle . the bodywork to reach them) by a single 12v /12Ah one in a new position atop the airbox, just behind the steering head. This not only offers improved accessibility, but also helps compact the mass of the bike to improve handling, according to Martini. A gloomy but fortunately dry day spent in the hills behind Bimota's Adriatic base revealed the SB6R to be better balanced than I remembered its predecessor being. The 46mm Paioli cartridge forks with carbon-clad alloy sliders to reduce unsprung weight are a holdover from the old bike, but with reduced internal tolerance on the stanchions, so' there's less stiction than before, says Bimota test rider Gianluca Galasso. The steering geometry remains unchanged, but a combination of the slightly longer wheelbase and an allnew, less-progressive link (1:3 now, instead of 1:4) for the rear Ohlins shock seems to have improved ride quality. It definitely improves traction out of turns and makes the bike less nervous under hard acceleration while still cranked over a little, and also improves stability arow1d fast, bumpy turns. The rear tire has been upsized to a 190/55 Michelin radial instead of the lBO-section rubber used before, though still with a 5.50-inch rear wheel specially made for Bimota by Ferrari suppliers An tera. I think this is too narrow for such a fat tire, but though Marconi admits to having tried a 6-in"h rear wheel, he says it makes the steering . heavier and the bike less nimble in changing direction. Thus they've gone back to the narrower rim, while Galasso insists that it's very hard to make the new bike slide with the 190-tire and the new link for the rear shock. Well, he's much braver than I am and he's also ridden the bike in warmer weather than my day in the saddle, when I did get th.e rear wheel spinning a bit, cranking it up out of turns on the gas. The jury's out on this until we go to a race track in warm, dry weather. Another major change on the SB6R is the new rear subframe, which is now constructed of carbon fiber rather than fiberglass. This ch.ange also has the effect of lowering the seat height slightly, says Galasso, who believes the SB6R riding position is so relaxed for a sports bike that "you can go to sleep at 240 kph (148 mph) on the autostrada." Yeah, right. But I will admit that it is more comfortable than before, without such a sense of being perched on top of the bike, though perhaps that comes from the slightly more all-enveloping bodywork. Still, the formerly widespread clip-ons have been pulled back to deliver a more comfy positioning than before, though the width of the new fuel tank is such that you lock your thumbs against it while making a tight tum in town. Some cutouts in the flanks of the tank would prevent this, as the tank is now separate from the seat W1it. Marconi says he's taken pains on the new bike to make everything more accessible than before, thus it features a first for a Bimota hyperbike: three-piece ~_:~~ota SB6R Engine water-cooled. DOHC. transverse in-line. 16-valve. four-cylinder . four-stroke with chain camshaft drive and oil heat exchanger Di_lons . 75.5 x 60mm Capacity .. .1074cc Output . . . . . . . . . . . . 145 bhp at 10.000 rpm (at wheeD Comp 1on ratio 11 .2: 1 CartMaretlon . . . .. .4 x 40mm Mikuni Slingshot with pressurized float bowls Ignlllon Suzuki CDI with single 12v/12ah battery five-speed with gear primary drive Clutch multi-plate wet straight·line connection twin-spar frame fabricated in Anti-cordel aluminum with cast·aHoy swingarm pivot/shock mount Su~.".n Front 46mm Paioli telescopll: fork with carbon·flber/alloy sliders. adjustable for preload. rebound and compression ...................fabricated aluminum swingarm with offset Ohllns shock and rising·rate linkage. adjustable for height. preIoecl compression and damping. ...... . . . . . • . . . . . . . .24 degrees Cadjusl8ble plus/minus 1.5 degrees) T 96mm ...... 418 pounds (dry) ........ , . " 53/47 percent T................ ..... . c..... ..... F 2 x 320mm 8rembo lIoeting cast·lron discs (or steel). with four-pislon Bnsmbo calipers ................................... 1x23Omm Brembo fixed steel disc with two-piston Bnsmbo caliper ... ......, Front 120/60 ZR17 Michelin TXI5TI on a 3.5·inch Antera wheel ...... . . . . . height F_ 190/55 ZR 17 Michelin TX25TL on a 5.5·inch Antera wheel . 32 inches Cllpac1ty _ut.etu..r , .......... _ Top.................. . :5.2 gallons Bimota SpA. Rimini. Italy 181 mph (Above) The Bimota uses a 46mm Paioli fork with 320mm Brembo disks and fourpiston Brembo calipers, highlighted In gold. (Right) Alan Cathcart puts the SB6R through its paces in the hills surrounding Bimota's Rimini, Italy, factory: bodywork, the separate tank and seat, and even the fact that the air £ilter is split in two so you can access the plugs to change them without practically dismantling the entire bike. But that morerational riding position, and the much thicker seat padding, means that for the first time it should be possible to actually enjoy a long point-to-point freeway journey on a Bimota, thanks also to the shape of the fuel tank which allows you to rest your chest on it at high speeds, tucked away bel1ind the well-designed new fairing. The fairing actually is a little narrower and more slippery than before, because of the replacement of the oil cooler on the old model by the watercooled heat exchanger from the Suzuki GSXR750, while Bin10ta also has delved into other Japanese parts bins to fit a new, bigger water radiator borrowed from the Yamaha YZF1000. nus delivers a more constant engine temperature at all speeds and in all climates - BO C (176 F) is optimum water temp, says Marconi, while oil runs at 110 C (230 F) normally. But it's the vivid response and the take-ne-prisoners torque of the Bimota's Suzuki motor that give you such a constant buzz when you ride the SB6R. This bike is so much fun and so forgiving to ride - much more so even than the old SB6, which was really more of a trafficlight special that' could go around corners pretty well. The new bike is much more ridable, in turn encouraging you to ride it harder around switchback Italian mountain passes and tWisting seaside roads - when you may be relieved that the Brembo brakes fitted to the new bike have noticeably more bite than before, thanks to the Brembo master cylinder fitted instead of the Suzuki one used before. But the flat midrange on the old SB6 has had the ditch in the powerband filled in, and the result is a bike that drives okay from as low as 4,500 rpm, pulls strongly from 5,500-6,000 rpm upward, and then delivers an extra kick of power at the very top end, between 10,50012,000 rpm, when the engine suddenly starts to pick up revs even faster, a bit like a two-stroke (but then Bimota knows all about them, doesn't it). That twin-peaks turbo effect is most noticeable in fourth gear - well, you might really notice it in fHth, except I couldn't find anywhere long enough and wide enough to get the bike cranked wide open in top gear. The power is delivered, thanks to the ramair effect at higher road speeds of the fresh, clean charge being fed to the pressurized airbox via the new air intake above- the radiator. Marconi admits that with the revised system and the pressurized carbs, the bike actually ran worse on the dyno than the old one, thanks partly to engine heat contaminating the flow of air. And it was only once they started testing it dynamically with a forced, pressurized airflow obtained through forward motion that the benefits of the new system became apparent. Everything's relative when you're talking Bin10ta prices, but at $21,793 in Italy, including 19 percent tax, the SB6R is only some $1,500 more than the bike it replaces, which was not only less powerful and slower, it also wasn't as much fun to ride and didn't have all the carbon-fiber gizmos hanging off it though strangely tl1ese don't include the exhaust silencers, which are in humble .. alloy, not even titanium: why? But that price is a bargain in Bimota terms, especially in view of the many detail improvements ain1ed at enhancing quality, which are evident when you look closely !it tl1e bike. Like the analogue instrument cluster, which is digitally operated, so you have the best of both worlds; or the stainless-steel sheaths encasing all the wiring; or the superior fit of the three-piece bodywork; or the clip-on cover to the engine airbox, which is quickly detachable, or - well, let's just say that the SB6R delivers. Value for money, performance, relative comfort, rideability and sheer class. Any bets on how quickly they break the 2,OOO-bike barrier with this one? tN ... 00 ~ n:l ;::::l ~. -- 15

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