Cycle News - Archive Issues - 1980's

~ .., e ~ 00 O"l ....... ....... ....... ;>.. .... C\l . :s c C\l ~ Recognizing the p ro blem , H onda ins tea d is offeri ng a th ree-stage kit to tra ns form a street VF750F into a TT FI ra cer: th e engine package includes a co m pe titio n ca mc ha in set -up p lus n ew h eads, va lves, p istons a nd so o n, pi us a single oversize wat er radiator. There's also a close-ratio gearbox kit, a nd finally a third package whi ch features pair of British-made Dym ag wheels, a full fairing , 6.3 gall on fuel tank, front and rear sus pe ns io n (sp rin gs onl y) a n d other bits a n d pieces. Prices ha ve yet to be det er-' mined, but all this stuff should be ava ila ble ea rly in '84 an d will be of particular interest to potential en du rance co m pe titors. The use o f the Dymags is interesting, because accordin g to Barry Symm on s the Comsta r typ e wh eels fitted to th e RS cos t $2,250 a pair and are " no t very robust. " Like th e Su pe r bike, th e RS850R 's engine is rotated back in th e chas sis by 8° to allow a steeper h ead angle (in this case 25°) and shorter wheelbase (56" ) for manageable handling than would otherwise be the case. Even so, Wayne would like to bring th e front wheel back a bit more, but there just isn't th e room to do it : the front ca msha ft cov er gets in the way . Even so, com p are the H onda 's 56" wh eelbase , with th e 90° V4 en gine and the extra bulk of th e oil cooler/radia tor with the 60" of the V-twin , a ir-cooled 900 Ducati, and th e feat of th e Japanese designers becomes apparent. Watercoo lin g is the rea son, for without h aving to worry a bo u t placing th e rear cylinder where it 'll get a good su p p ly of cooling air, you ca n simpl y p osition th e engin e in the chassis where it'll result in the best handling characteristics, Suspension is by m eans of a sh orter version of th e 4 I.3m m Sh ow a front forks fitted to th e Superbike , and the sa m e nitrogen-damped rear u n it. Brak es are the sam e di ameter up front, with a 220mm rear, and a ll appear to be ' made 'o u t of 'so me 'eso- . • teric alloy that has more than its fair a _ . 5.8 sh ar e of cas t iron in it: they ru st wh en wet l Steel nuts and bo lts are used th roughou t, rather tha n titan i u m as in th e a lloy-fra me d specia ls, and th e bluff-fronted, wind tunnel tested bod ywork bear s a stro ng fam il y rese m blan ce to th e NS/RS500's strea m lin ing, with the sinuo us pai rs o f exha us ts exiting on th e ri ght side, th at from the rear cyli nde rs th rough th e top of the seat. In struments are co n fined to a rev counter an d wat er temp gaugeth e latter a vit al fixtu re si nce much to my surp rise it transp ired th at th e engi ne overheat s rapidly a t idle, an d o nce it hits 204° yo u must sh u t down or ri sk serio us damage - like a blown gas ket. In fact , the bikes were kept wai ting so long on th e grid for the sta rt of th e Assen World TT FI round that Wa yne 's bike ove rhea ted so much th e seat ac tua lly melted! Cracks a bo u t as bestos underw ear need not be mad e! Th e riding p osition's a snug but comfortable fit. with th e big 6.3 galIo n fuel tank nest ling into yo u r ch est a nd providing a useful rest o n long fast stre tches. Bottom gear is very low , but even so with 11 .5: I co m p ression it needs tw o peopl e plus the rider firml y seated to bump-start from co ld. Fortunat ely , th e "engi ne fires a lm ost at once a nd settles down to a fast, eas y burble, but solo push -starts would be o u t of the question . Once out o n th e track , I dis cove red th at first is a lso much too lo w to use excep t. for getting off th e lin e. Before I managed to work this o u t, I'd sta lled the engine twice trying to cha n ge into the ver y notchy bottom gear. Fortunately, it restarted with momentum, but it a lso illustrated ano the r fea tu re of th e engine : th e flywh eels have surely been reduced i n size co m pared to the ro ad bik e, beca use their effect on engine brakin g is a lmos t nonexistent a nd th e engine di es a lmost immedia tel y if you close th e th rottle. As mechanic Dav e SIea t neatl y put it , it's a two-stroke engi ne in four-stroke g u ise. . Except for one thing: that incredible power band. With the extra IlOcc and different ca msh a fts the 859cc engi ne is even torquier th an th e 750, if th at were p ossible. Power co me s in at 6,000 rpm , with normal p eak revs a t I 1,500 , th ough th e en gine is safe to 12,750 rpm. Th e rough pa tch is th ere, too . but thi s time hi gher up th e di al a t aro un d 8,200 rpm . But with th e beautifull y matched gear ratios yo u would never ~n co u nt~r it normally: seco nd a nd third ar e 1,700 rpm ap art , to keep th e bike m oving right a long under ac celera tio n from a corn er then th ere's o n ly 1,300 rpm before fourth , and fifth is very close to fourth indeed - on ly 1,000 rpm differen ce! Taking a left /right fli ck turn-Russell s-meantjusl not ching fourth o n th e wa y in , and driving hard up th e hill to th e start line before grabbing for th e run to Rich es. Then ba ck to fourth before co m in g down to seco n d for Sear, then off down the straight. The smoo th power deliv ery and excep tiona l flexibi lity of the engine really to ld in minimizin g th e number of time-consuming gea r ch anges. . S l ig h tly und ergeared for th e stra ig h t, I was ac tua ll y seeing I 1,900 o n th e clock before sh u tt ing off for th e h airpin, a n d here th e fabulou s brakes rea ll y ca me into their o wn . Aft er 15 laps or so I was a ble to brake from over 150 mph wi th in the 200 yard mark (and I'm not kidding myself that Wa yn e doesn ' t wait until even Iater l). The fr ont di scs re spond instantly with maximum effect, and the back has lots of feel as well, whi le th e anti-di ve works to advant age when negotiating th e ripples a t the end of th e straight before h eeling over into th e left-hander before the hairpin. In other words, th e suspension doesn 't freeze up. Lever ac tio n is light but not so much tha t it's possible to overbrake, and indeed a ll the controlsth ro ttl e, brakes, clutch-were fea ther light and positive. What a great bi ke to go endurance racing or round the Isle of Man wi th. As a heri tage of all those production bi ke races h e did in Austra lia, Wayne uses a one down, four up gearchange on the left, which took a bit of remembering, but th e change itself was like butter and I didn 't co me clos e to mi ssing a gear even riding as hard as I was. T he h andling is literally aweinspirin g . Though a big, relat ivel y bulky bike th e H onda cha nged direction precisely at th e corners and steered lightl y but positively. By ultra-critica l sta ndar ds th e steeri ng wh eel could be qu icker, even without th e 16" front wh eel fitt ed , bu t there's no way to improve th at without stee pe n in g the head a n gle furth er. After a few laps o f gradually pi ckin g up th e pace, I se tt led into an easy r hy th m o n th e bike in spite of the fas t lap times: I co u ld hav e gone on ridin g it all day. Sadly, aft er 25 lap s or so th e front wh eel stepped out accele lera ting o u t of Sear and th ough I managed no t to do a prem ature job in th e crush ing department a n d picked it up before I landed on my ea r, playtim e was over. T h e front tire fitted was onl y an intermedia te, and it was cutting up badl y on th e right side. With no slick in h and , it was time to ca ll it a da y a fter o ne of the most enjoya ble rides I'v e ever had on any bik e: " I never thought you were going to rid e it th a t hard , else we'd have brough t a slick," said Dave Sleat , whi le Barry Symmons just looked relieved th at he still had a chassis to sell a t th e end o f th e day! But the RS8 50R is th at sort of bik e: it invites being ridden h ard , and lets you do it safely. Wh at a sh ame I don't have a wea lthy spons or who'd buy one for me! •

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