Cycle News - Archive Issues - 2000's

promises to include an "upg ra de kit ," whatever that is, w ith each bike so owners can choose their own settings if they wish . However, not only is the TNT's ride q uality in stoc k gu ise ext remely good, especially for such an uncompromising-looking piece of hardware - o nly the Ap rilia Tuono matches it, w ith for example the hardassed Monste r 54R no t nearly as good - the une xpected ly so ft sus pensi o n settings are ve ry co mpliant ove r ro ugh surfaces and a ll but t he w orst bumps o n frost -ravaged mountain passes, and it takes a big ridge of broken tarmac to leap the Benelli in t he a ir and bottom o ut on landing. In normal use t he sus pension is excellent, and my oid teammate Gian luca Galasso, now Be ne lli's test rider, d id a good lob in refin ing th e TNT' s hand ling. And in spite of the soft fork settings, t here wasn't undue front-end dive e ven braking hard into a tight hairpin , when the Brembo brake package did its usual good jo b slowing the Benelli down and t he chass is setup allowed trai lbra king into the turn without undue weight transfe r. Th at 's w hen the T NT's undue 52/48 percent frontal weight bias by Naked bike standards came to the fore , allowing the I 20/65 front Dun lop to grip hard as you ke ep up turn sp eed, knowing that t he front end won't wash out as you use the good leverage of th e wi de han dle bar to e xplo it the light, pr ecise steering. This really is a great bike fo r switchback hillside ro ad s, whe re that combinat ion of m eaty torq ue and deft steering, co up led with good brakes and mo re than adequate suspe nsion respons e , wi ll get t he Be ne lli hustl ing between hair pins faste r than almos t an ything else on the road. At Euro 12,900 [a bo ut $ 15,299) in Euro pe for any of the three standard co lors it comes in - red, yellow or black - or an e xt ra Euro 500 [about $600) as t he cost of personalizing it in the color of your choice (like Benelli's trade mark green, m aybe? Funny tha t's no t a stock option), given its superior performance and freshe r styl ing, the TNT I I 30 is co mpetitive ly pr iced against th e Euro 10,900 [about $1 2,899) Spe e d Triple - Italy 's best-selling Trium ph model, and the new tr iple stre etfighter 's only dir e ct co mpe tito r. Ho wever, hate to say it , but this is the bike t hat Benelli should have been m aking all along .. or ra ther, t he engine is. It ca n on ly be a matte r of t ime before the lo ng-stro ke motor finds its way into th e w im pish-bycom parison Torn ado Tre (su rprise: Galasso already has one un der test!) to give substance to Benelli 's claim to have produced the first-eve r long-st ro ke spo rtbike . The TNT I 130 isn't that, yet - but it surely is an ext re m e ly effective rea l-world fun -b ike , the fo rerunne r of a coming rang e of spin off Be nelli maxi -models, including a spo rts to urer an d a tarmac t ra llie, as well as the ultra-Tornado . It's a bike th at delivers everything it pro mises , o n pape r as w ell as by a ppearance . T hat TNT monike r 's e xplosive e xpectation s are e xceeded: Just twi st the wrist and go! eN BENELLI TNT 1130 TECHNICAL: Tractor Tech Though the overall concept of the T NT I I30 of course belo ngs to BenelJi's progellista, Adrian Morton, the one responsible for translating his ideas into metal is the man who's been the company's chief engineer for the past three years , Ing. Pierluigi Marconi, formerly with Aprilia, where he created the RSTI000 Futura. But before that, Marcon i spent a decade head ing up the engineering department at Bimota, whe re he was responsible for the small but prestigious spec ialist firm's best-selling 586, DB2 and YB9 mod e ls, as well as the somewhat less successful Vdue 500 twostroke, and of course the avantgarde, hubsteering Tesi ID. To create the longstroke TNT evolution of Benelli's trademar k three-cylinder dohc Tomado motor, Marconi and his R&D team left the Iiquid-ccoled engine's BBmm bore well alone but lengthened the stroke from 49.2mm to 62mm to create an 113 Icc vers ion of the 12-valve power unit with its 120-degree crankshaft th ro ws, which measu res 89Bcc in Tomado 900 guise. With a genu ine 135 bhp at 9200 rpm, according to Marcon i, the result delivers essentially the same maximum horsepower as the smaller-engined 137bhp sportbike, though at lower revs than the Tornado's 11,800 rpm peak - but the big difference comes in the TNT's torque curve, which is substan tiallystronger and much fiatter all the way through the rev range. To achieve this muscular earth-moving motor, Marconi and his team not only lengthened the stroke - which of course necessitated also rebalancing the engine and altering the weight of its vibration-taming single gear-driven balance shaft but also fitt ed a redesigned inlet cam offering Imm less lift, as well as shorter conrods. "The eng ine naturally revs much lower than the Tomado, wh ich is limited at 12,000 rpm , whereas the TN T's is set at 9800 revs," explains Marconi, "so we've been able to use shorter rods, which in tum improve piston acceleration and thus engine pickup all th rough the rev range ." Also new is a more fuel-efficient hem ispherical combustion chamber, though still with the same 33mm inlet and 29mm exhaust valves as before, which allows Benelli to attain an 11 .5: I compression ratio on the TNT ( 11.7: I on the Tornado ), in spite ofthe bigger capacity, and whose effect ive des ign is one facto r in allOWing the new bike to meet Euro 2 emissions regulations without the use of a costly, heavy and bulky catalyst exhaust. That's quite an achievement. To hamess the extra torque, an extra plate has been added to the II -plate, oil-bath clutch, which is no longer a mechanical slipper des ign, as on the Tornado. Instead, the new bike features a vers ion of the same pneumatic anti-lock system as on the Aprilia Mille, which in tum borrowed the idea from the Gilera-engined 8imota 5upermono racer, which Marconi designed back in 1993. The same six-speed extractable cassette-type gearbox (use ful for 5uperNaked racing!) used in the Tornado is re tained, with identical ratios , but with a fove-tooth-bigger rear sprocket to lower overall TNT gearing to 16/36. Marconi has also lengthened the intakes by 50mm, to improve bottom-en d torque, and the exhaust headers by 200mm, for the same reason. But a big step forward on the TNT is the adoption of dual e lectronic flap-type valves installed in the airbox intake duct and in the EXUP-type exhaust collector box, Jointly controlled by an e lectric motor via the fuel-injection syste m's ECU and whose operation is mo nito red by the angle of the throttle butterflies and the rpm . "T he twin valves remain closed below about 4000 rpm, with the exact figure depending on the throttle opening, but then open progressive ly in tandem as revs rise , unt il at a certain numbers of revs - again dependent on the butterfly angle - they're fullyopen," explains Marconi. "Th is improves torque, red uces noise and enhances em issions figures, so it' s a very worthwhile benefit." The same 53mm Dell'Orto throttle bodies as employed on the Tomado are retained on the TNT motor, each still fitted with a single injecto r but located in an all-new airbox, while the engine man- www.cyclenews.com age me nt system's ECU is no longer a Bologna-made EFI, but instea d an all-new design fro m 5agem, now owned by the American Walbro concern . According to Marconi, th is new ECU is a more soph isticated microprocessor which not only has the ability to control the dual inlet/exhaust valves, but also offers an auto-mapping facilityvia the lamda sensor on the exhaust, thus allowing the factory R&D team as well as dealers and customers .. to work on the engine or exhaust system without needing to remap the EFI manually in order to gain advantage from do ing so . It was evidently a factor in speeding up R&D and explains how Benelli brought this heavily revised engine to the marketplace in under two years. The TNT's composite chassis design, with twin-tube steel side spars keyed into the aluminum cast ings comprising the swingarm pivot, is essentiallythe same as the Tomado's, but with a slightly different posture - it's been raised I5mm at the front and lowered I5mm at the rear, and the head angle for the no nadjustable 50mm Marzocch i upside -down forks has been kicked out by half a degree, to 24.5 degrees: Trail remains unchanged , at 102 mm. Though for aesthetic reasons the TNT's tubular steel swingarm is all-new compared to the sportbike's aluminum structure, with a mo re convenient eccentric chain adjuster rather than the Tomado's axle slider, it's the same length as before, and the two bikes share the same 1419mm wheel base , but with significant alterations to the layout on the T NT. The most immed iately obvious of these is the removal of the water rad iator from behind the engine - thus also obviating the need for the twin extraction fans beneath the seat, which in turn makes space fo r the 3-1 exhaust's silencer to be aggressively positioned in the ir place, rather than hung out the side, as on the Tornado . Fitting twin laterally mou nted radiators on either side of the steering hea d on the TNT has two key benefits, according to Marcon i. "First, it significantlyalters the weight distr ibution to compensate for the lack of bodywork in putting more weight on the front wheel to improve comering grip ," he says. "Th e weight distribution of the TNT is 52/48 percent frontwards, which is a grou nd breaking figure for a Naked bike, most of which are at best 50/50 but mostly 48/52 or worse, wh ich impacts negatively on handling and especially fro nt-wheel traction in fast tums. But secondly, it also allows us to substantially lower the seat height to 780mm against the Tomado's 830mm, which is vital for a Naked bike like this in allowing us to produce a more comfortable motorcycle which is easier to ride and will appeal to a wider market, also including women. The fact it's also much narrower is an added bonus !" The enhanced front-weight bias has partly been achieved with a 120/65-17 front Dunlop D207, which Marconi says de livers excel lent stability at high speeds without compromising steering compared to the more normal 120/70 front tire , matched to a fat 190/50-17 rear. "We tested this at Nardo, where Galasso was able to take his hands off the 'bars at 250 kph [ove r 155 mph) without any instability," he says. "Plus, compared to the 120/70 tire , it gives sharper steering at lower speeds - it's really noticeable." The lightweight five-spoke wheels are cast by Brembo to Bene lIi's design , wh ile the Ergal-bodied lightw eight Extre meTech rear shock is the same as on the sportbike, though here adjustable only for spring preload and rebound damping, no longer for compres sio n, but with the same progressive link. It's also fitted with an ident ical Brembo brake package - a 240mm rear and tw in 320mm discs up front , gripped by four-piston calipers which are not , however, the radially mounted four-pad ones of the latest higher-spec RS Tornado, but the conventionally mounted twin -pad calipers of the base-level sportb ike. No doubt we can expect a TNT Corsa variation on the Benelli Nuda theme before too long, fitted with radial brak es, Ohlins suspension and a track use -only exhaust, reatly to kick Aprilia Tuono Racing's ass in the flourishing 5uperNaked race category now gaining pro minence around the world . First, though , Benelli's boss Andrea Merloni will be aiming to do the same in the showroom. CYCLE NEWS • MAY 12, 2004 73

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