Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127768
. . ·R C RTE r Bimota SB7R AE S • By Alan Cathca rt Photos by Kel Edge im e s cha nge . Eight yea rs ago, Bimota was on a roll, racing-wise a t lea st, with th ei r new Yamaha FZ750-engined YB4EIR - the world 's first fuel-injected four-cylinder Superbike. After clinching the 1987 World IT F1 Ch ampionship in th e bike' s d ebut season (courtesy o f a cer tain Virginio Ferrari) the sma ll Italian factory went in to th e final race of the in a ug ura l World Superbike se ries the following year with rider Davide Tardozzi leading on point s and poi sed to take the title. Only he didn't - and though they fur the red their role as Ducati 's involu ntary fa rm team b y groo ming G iancarlo Falappa for world honors in 1989, Bimota never again ai med to be a force in World Superbike racing - until now. In 1995, they started over. Riding on th e cres t of a commercial wa ve, street bike sales having dou bled for 1994 over the years before, Bim ota took the first steps on the comeback trail with an SB7 d evelopmen t bike tha t was originally supposed to be ridden by Terry Rymer for th e whole of th e World Superbike series. But spo nsorship deals we re slow to ge l, so it was onl y in mid-Febru ary that the team wa s sure of going racing and work could begin on development leavin g th em critically short of time to get on the pace with their bike. Especially in light of the fact th at it would be powered by th e obsolescen t, li q ui dcoo le d GSXR750W Suzu ki mot or, but fitted with e lec t ro n ic fu el in jecti on d e vel oped by Bim ot a in conjunction with TOD in Bologna. Th e SB7R w as blat antl y lack in g in d ev elopment when it lined up for the first round at Hockenheirn, Rymer failing to even qualify. The engi ne lacked acceleration and had a time-lag thr ottle respo nse. Top speed was respectable for a d ebu t appearance - 177 mph through T VER th e t rap s was a ll righ t for starters ; the problem was getting there . The failure to qu a lify co nv ince d Rym er the b ik e w asn't ready to be race, so h e left th e team. He w as rep laced b y So uth African 250cc cha mpi on Rus sell Wood, who had ridden for Bim o ta bef ore on their hub-center Tesi Superb ike. Thoug h h is ra cing commi tm e nts b ack ho me precluded his rid ing the SB7R a t e ve ry · race, Russell at least got th e bike in to races , and even came close to scori ng points at Monza before handing the m ach ine ov e r to Supersport rider Stefano Pennese for a couple of races. Bimota's lackluster return to Superb ik e racin g e n ded at Assen, wh en British guest rider Mat Liewellyn also fail ed to qualify (afte r lappin g the Brands Hatch short circuit at lap-r ecord pace after the world su perbi ke round there). The reaso n was obvious to an yone watch ing: The damp track made the Bimota ' s ra zor-ed ge power de livery even more pr oblematic. Mat did we ll keeping it uprigh t w he n th e p ow e r chim ed in b ig-time more than once at the chicane! Fortunately, wh en I came to ride the SB7R during a Bimot a tes t session at Misan o, the sun was shining, the track was dry - but still the bike was a handful. It does feel good to sit on, and sha rp to steer. It's low, small and definitelv the m os t co m pact in -lin e fo ur-cyli nder Superbike I've ridd en th us far, ye t not so m in iscule th ere isn' t anywhere for you to sit except perched on top with all yo ur bo dy weigh t on arms and shoulders. The SB7R has a close-coupled riding position like its low-slu ng street sister, wi th which it obv ious ly shares the sa me distinc ti ve "S t raigh t Line Concept" twin-spar alloy chassis. But problems begin when you try to gas up the fuel -injected Suzuki motor. Its power delivery is a bit like the fourstroke equivalent of a pre- Big Bang 500 GP ra cer - ex cep t the Bim ota has th e push , bu t no t the s hove! The engi ne pulls adequa tely from about 9000 rpm, which is when the varia ble-length trumpets fitted to the 46mm throttle bodi es start to contract; they're elec tro nically controll ed off the TDO engine management system in respon se to butterfly angle and rpm, and shor ten progressively over a 40mm range between 9000 and 12,500 rpm, in o r de r to fat ten th e m id range power. Bimota's ch ief engine er Pierluigi Marconi says he knew from the start after working on the SB? road bike that getting the Suzuki to short bu t un mistakable lag before the Suzuki engine responds to you r wristtwist - and then it does, the picku p very s ud d en and jer ky. It 's no t a s m ooth, immedia te response like other fuelinjected bikes, but an abrupt pickup tha t isn 't even as relatively p red ictable as a motor fitted wit h flat-slid e carbu retors like a Yamaha o r Kawasaki . It a ls o doesn't pick up revs as fast as one of these. Engine acceleration is more measured, perhap s becau se the 70 x 48.7mm Suzuki engine has the longest stroke of any Japanese Superbike motor. All of this means that as you start to get back on the gas in the middle of a tum , it's very hard to feed the power in prog essivel y. In st ead , yo u get all or nothing. Small th rottl e ope nings d on't have any real effect, while half a tum on the gas sud denly kicks the engi ne hard, causi ng th e rear tire grief as it tries to cope with the su dden rus h of horsep ower. Then, when the rear wheel does hook u p a nd th e en gine is on the p ipe, th e power push es the front wh eel in a d is-