Cycle News - Archive Issues - 1990's

1--- - - , Yamaha YIF 1DOOR Thunderace Specifications ENGINE ing the relatively slow stee ring when changing d irection . It's a trad e-off. Yamaha has m ad e every eff ort to save as mu ch weight as possible on the chassis of the new bike, which weighs in at 28.16 pounds compa red to almost 40 on the FZR, and is also 5-percent stiffer, Yama ha claims . The new swi ngarm is a massive 52-pe rcent stronger torsionally a nd 25-p er cen t stiffer la te ra lly th an befo re, at a sligh t l.75-pound penalty in weight, but the resu lt is th e incredible feeling of streng th an d robustness that the Ace d eli ver s, in spite of the much reduced 435 .6- po und dry weigh t, 35 pounds less than the old EXUP. Powe ring ou t of a third-gear bend at 7000 rp m, with the mega-motor's massive torqu e pushi ng you effortlessly to your next appoin tment w it h a tu rn as the rear 180 /55 Melzeler rad ial digs deep into the tarmac is a heady experience - provided the road surface is good a nd smoo th, or there 's ju st a sing le bump. in the road, wh ich the Ace's fully adj us ta ble sus pe ns io n package (co m- (Left ) New bo dywork surrounds the slanted, 1000cc in- li ne f ou r. A co nventional fro nt f ork provides f our in che s of travel. Fro nt brakes are the same 298mm units as th os e f ound on th e new Yamaha YZF600 Thundercat. (Below) Barebones instrumentati on is a co ncess io n to the s po rt ing nat ure of the beast. Large t ach and speedomet er ar e easy t o read at a gl ance. Type . . , ' Liquid-cooled 4-Stroke. DOHC Cylinder arrangement Forward-incltned parallel four-cylinder Displacement ' , ' 1002cc Bore x stroke 75.5 x 56.0 mm Compression ratio 11.5: 1 Maximum horsepower . ' 145 hp @ 10.000 rpm Maximum torque , , 79.87 lb.-ft. Starting system Electric Lubrication : _.·.Wet sump Cart.uretion " Mikuni BDSR38/ 4 Primary reduction ratio 68/41 (1.659) Secondary reduction ratio _ 046/ 17 (2.706) Wet. multiple-disc C lutch type Transmission type Constant mesh five-speed Gear ratio 1st 36/ 14 (2.571) Gear ratio 2nd 32/ 18 (1.778) Gear ratio 3rd , . .. ..•.. 29/21 (1.381) Gear r atio 4 th , , .27/23 (1.174) Gear ratio 5 t h 28/27 (1.037) Ignition syst em TCI (DigitaD Final transmiss ion ; , .Chain CHASSIS Overall length ,82.08 in. Overall widt h , , ' 29.13 in. , ,46.25 in. O v er all height 31.1 in. S ea t height Wheel b a se , , 56.3 in. 5.51 in. M inim u m ground c learance Dry weight 0435.6 Ibs. Frame typ e , .Aluminium Deltabox Head angle 24.0 degrees Trail , 97 mm Fuel tan k capacity 5.2 gal. Front suspension Telescopic fork Coil sprtnq/oll damper Fr on t shock absorber Rear su sp e nsio n Swinging arm (fink suspension) Rear s h o c k ab so r b er Coil-gas sprin9/o il damper Front w h eel MT3.50 x 17 Aluminium Front wheel tra v el 4.72 in. Rear wheel ' MT5.50 x 17 Aluminium 04.72 in. Re ar wheel trav el Front b rake . , Dual disc. 298 mm diam. Rear brake .Sinqle disc. 245 mm diam. Front tire s ize _ 120/70 ZR17 Re ar tire size .. . . . • . . . . . . . . . . . . . . . . .180/55 R17 J (Left) The large ex haus t can ister f low s n icely with the swoopy ta il sectio n. Th e redes igned rear sw ing arm is cla imed to be mu ch stronger torsio nally than that f ound on the old FZR. Rear br ake is a 245mm unit. pression rebound and p reload can all be quickly altered at either end) can shrug off. The problem comes w hen you hit a series of bum ps on sta ndard se ttings, either on the w inding coast road which first alerted me to the problem, or next day on the Killarney race track's bumpy tu rn s, w hich compou nded it. On the highway, the rear wheel hops and cha tters even on part-t hrot tle, the otherwise accep table ride qua lity is seve rely compromise d, and you spe nd a lot of time standing on the footpegs to avoid being tossed up in the air over the forthcoming series of bumps. In a pure Su persports bike aimed prim arily a t tr ack ac tio n this mi gh t be und erstand able, bu t by Yamaha's own ad m iss io n, th e Thu nd e r ace aims a t so mething more than this: it' s a su pe rsport-touter. so it ne ed s to be ab le to co pe with th e rough stuff as well. A two- hour sus pe nsio n sorting session at Killarne y with Yamaha test rider Dave Bean su pplied the ans wer: On standard settings, there's way too mu ch rebound damping on the rear shock. One bump, it ca n co pe w it h - but show it two or m or e in swift succession, and the fact that the shock is still held down on comp ression means that sus pension reponse is grea tly compromi sed, lead ing to a fit of the yu mps and rea r-w heel cha tt er . H o ld ing d o wn the back end on th e r eb ound d a m p i ng also affec ts r ide height and weight dis tribution, leading to the bars flap ping in you r han ds if you get hard on the gas wh ile rid ing the rippl es, becau se the front end's gotten all ligh t since the r ea r e nd's still compressed . Okay, so tha t may only happen when you go for it on the race track, not neces. sarily the su per sports- touree's natural hab itat - thou gh wi th some care in softing up the suspensio n, the Thund erace's st ability and hu ge reserves of torque could allow it to sp ring a su rp rise on the Fire Blades in the Isle of Man's Production TT this year, as we ll as in World Supe rbike's new Open Superstock class. But street squirre ls will wa nt to explore the handling limits, too, and u nless they take a lot of time to seek a radically differen t r ear-su sp ensi o n se tting from stock, they won' t like the way the Thund era ce handles on a bu mpy road; six turns off rebound, two turns off preload at the rear (the' opposite of what I no rmally have to d o wi th my weight) an d tw o tu rn s more comp ress ion started to ma ke the bike han d le better - but then the soft se ttings on the big 48mm conventional (not upside-down ) forks sta rted to becom e a problem, because now that the rea r suspension was beginn ing to wo rk properly, it started to pogo the front end. Two turns more preload and no less than four clicks more rebound damping started to make things better, before we ran out of time. But I do think Yamaha need s to ta ke a closer look at the way the FZRI000's suspension is set up, given that market research ha s shown that the vas t majority of customers never adjust the suspension settings, but relaxin the warm g low of knowing they could if they wanted to. Yamaha has rifted the exact same brake package to the Thu nderace as it has to the ligh ter Thu nderca t - bu t since these are the fantastic one-piece Sumitomo four-pot calipers, that's a rea l bene- . fit. The re 's the same total s toppi ng power from high speeds, only you do have to squeeze quite a bit harder to get the job do ne, mainly because Yama ha has kept th e same 298mm discs as on the smaller bike in order to reduce the gyroscopic effect on the handling that bigger, heavier brakes would dictate.' But althoug h there's the same excellent reponse at low lever pressures, such as when you go too d eep in to a turn an d, just wa nt to knock off a li tt le excess speed, a bigge r master cylinder than the 14m m one fitted to the Ace migh t be preferable so as to get more bi te fro m high speeds on the heavier, faster bike. Still, th ese brak es are fan tas tic: Wa tch them becom e a fav ored com po ne n t of the special parts bin in coming years! With a n excellen t leve l o f fi nis h, aided by the plastic cladding that tidies up the look of the inside of the fairi ng, an d a choice of red / white or black / grey paint sc hemes, the Thunder ace looks sharp a nd swoopy - a tr ue o rig ina l, styling-wise. Its a pity there are no passenger grab-hand les on the rear bodywork, like on the Ca t, and even more of a shame th a t th e EXUP's fu el reserve switch hasn't been retained - presumab ly'"for the sa me reasons of cost that ap parently p revented a ride he ig h t adjuster being inco rporated in the rear shock linkage; BuI Yamaha is eager to hold the price of the Thunde race down to below the competition, making this a lot of motorcycle for t h e mo n ey : a megabike bargain that looks d ifferen t and goes great. Its a very different kind .of bike from the CBR900RR - more comfortable, more practical and ultimately more, well , m or e r id ab le than the Honda, even though it has n't got the sa me top-end zap or razor-edge handling. Instead, the Yamaha is the bike you'd choose to ride very fast from one side of Europe to the other on - say, from London to Paul Ricard in one swift swoop via the French autoroutes, perhaps with a passenger, then to spend time exploring its handling abilities along Provencal mountai n passes and corn iche coast roads, before a high-speed ru n home. The Thu nd erace is a high-speed milester wi th the soul of a race r - a fact underline d by the effortless torque and 125 mph-plus cru ising canter of the big bore m o tor, co up le d with t he co m pa ct d imensio ns of the alloy Deltabox chas sis, based on the race-bred geometry of the YZF750. Like with the Ace's sma ller YZF60b T-eat sister, Yamaha has aimed at offering the best of both worlds, and come commendably close to delivering jus t that with a bike that' you can ' t help feeling is m ainly ai me d a t th e hi ghspeed su pe rtou rer Euro-market. If you wan t a Yamaha-engine d Hyp ersp ort s a nswer to th e FireBlade righ t away, you' ll need to spen d upwards of 50 percent more mo ney an d bu y th e 'n e w YZFI000-powered Bimota YBl l. Either that, or wait for Yama ha to prod uce a true cutting-edge one-li ter sports bike. Is that why they're not selling the Thun derace in the United States in '% ? l-:\

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