Cycle News - Archive Issues - 1980's

The rear suspension is on the left hand side and the rear swingarm is connected to the rocker by a short rod to the rocker's l ow er end . The middle pivots on the rear of the left side plate and the top i s connected to the top of the suspension unit. In these photos the rear unit has been removed but the lower end is mounted on the swingarm and the mounting hole can be seen just in front of the wheel rim. The gas tank is slung under the engine and a small Keihin diaphragm pump works off the inlet tract of the left t op cylinder t o pump fuel up from the tank to the three carbs. The pump can be seen j ust to the rear of the top front swingarm pivot. New Elf seen at Mugello By Peter Clifford The latest version of the exci tin g and revo lu tionary £1£2 Grand Prix road racing machine had its first outing d u rin g a secret test session at Mugello on the Monday after the Italian G ra nd P rix. With no fra me so that the fro nt a nd rea r swingarms are bolted to sp ecially-redesigned H onda RS500 engine , 26 the Elf is something special. Even without seeing under the fairing it looks to be an advanced p rojec. 1 . t ~ ;a~1 a " 1 \ • "l tile cu tt ing through th e ai r with its slop ing, winged nose. Benea th it sit s the solid looking cast front wh eel held by the pa ir o f swinging arms. Situated on the right-hand side o f the wheel they hold the hub center steering. The rear wheel is mounted in a single swingarm on th e left of the machine. II ' I \ J ":I Jt l l ~ · 1 J t. I~ J Jlj l . l.. .; The most interesting aspect of the Elf though is what h ap pe ns between th e two wheels. Sin ce th e ma chine was first revealed a t the French Grand Prix a t Pa ul Ricard , Andre de Cortame a nd his design tea m have been hard at work and it has cha n ged a good dea l. It now has special cast magnesi um sidecovers on the sta ndard Hon da crankcases and these hold all the steering and suspens io n pivot points. The suspe nsio n units on the 1984 version ar e both mounted under the engine but now they have been mov ed to sit o n eac h side of th e en gine a bo ve th e cra n kcases . The front sus pe nsi on sits o n th e right hand side o f th e engine with its low er en d mounted o n th e rear o f the side cove r a bove th e clu tch. The top en d is co n nected to th e upper en d o f th e front rock er arm. The midd le o f th e ro cker a rm is connected to th e top swingarm a nd its low er end to a sho rt con nectin g rod th at is a nc hor ed in th e side plate just above th e front swinga rm p ivot. T he rear sus pe ns ion is o n the left hand side a n d th e rear swi ngarm is co n nected to th e rocker by a sh ort rod to th e rocker's lower en d. The middle pivots on th e rear o f th e left side plate a nd th e top is connected to th e top of th e sus pensio n u nit. The lo wer en d of the su spension unit is mounted o n th e swin garm . The unique feature o f th e Elf's suspension is that the front and rea r ca n be connected. This is done via a torsio n bar that runs across th e top of the gearbox. On ea ch end of the torsion bar is a vertical a rm which is connected to the top en d of each rocker arm. This mea ns that if the rear suspension is compressed under acce leration it draws up the front sus pe nsion th us lower in g the center of gravity so that the bike has less of a !e,n d.e~.IT , tf ••~~~J ioe ; .::r~~ , t~o s.uos~ pension systems do no t have to be linked a nd to sim plify development can operate independently. The lat est wh eel design is also so me thi ng special, being a combination o f cas t solid dis c wh eel and sp u n a lu mi n u m rim . In fact o ne side o f the rim is cas t with the so lid dish leaving th e base of th e rim and the remai ni ng side to be formed by th e spun a lu minum. There is a bead retain ing lip cast into th e bottom o f the rim on o ne side and a sim ila r lip form ed in th e spun sectio n . -, The tire is mounted by push ing it o nto th e sp un segment and th en bolting that to th e cas t dish. In the hubof th e d isc th e carbon dis c is mounted. Bo th front and rear dis c are com plete with no carr ier an d the front is seized by two four-piston Brembo ca lipers co nta in in g ca rbo n pads. The rear brak e em ploys a single four-piston caliper. The front disc runs very close to the center line of the wheel and hen ce there is very little turning mo vemen t in th e steering. T he ca li pe rs a re mounted on the steering p late th a t p ivots betw een the rose joints on th e fron t- ends of th e swi ngarms. T he stee ring p la te is turned back and forth by a rod that runs back para llel to and between th e two arms. The steering rod is p ushed for and back by an arm on th e right-hand end of a cross shaft that turns in beari ngs mounted in th e front of specially cast cylinder heads. The left-hand end of the cross shaft ha s an arm that runs up to a co n nectin g rod runni ng Io rward to the handlebar and dummy steeri ng head system . The rear of the cylin der heads are also employed and the 8mm bo lts that are normally headstays now hold the forward top end of th e cast side plates. The bottom low er point of the cast side plate is secured to what in the standard engine is the front engine mounting bo lts. The left-hand side pla te is also bo lted to the rear en gine mo unting point. O n the right-hand side the plate is split up and down from the hole on th e side plate where the ig nition triggers are o n the end of the cra n k. To th e rear of tha t th e magnesiu m casting repl a ces the cl u tch bac ki ng pla te wh ich is also the gea rbox cover and is held o n by th e standard 6- and 8mm screws. T he rear swingarm is a h uge cas t magnesiu m unit pivoti ng on the side plates on ly 1.2 in che s beh ind the final drive sproc ket. Although bifoca ted to go eithe r side of the engine like the front swinga rms, it on ly exte nds down th e left side o f th e rear wh eel. The rear wheel bearings are held in a huge aluminum eccen tr ic ca p tive in th e end of th e swingarm. As in previous Elfs th e sp rocket, on th e left side of th e arm , and th e carbon di sc, on th e right , remain in place wh en the rear wh eel is removed. The radia tor is very slim but tall a n d slo pes ba ck at 45 degrees. It runs up from th e front cylinder heads beneath th e dumm y steering head up to what o n most machines would be th e gas tank. On th e Elf, the gas tank is underneath so th e fibergl ass bulge in the o ne-piece fairing and set is just to make th e rider feel more at home and allow a ch a n ne l for th e cool ing air which co me s in over the fro nt wheel and passes through th e radiator a nd out over the back wheel. The gas ta nk is sl ung under th e engine and a sma ll Keih in diaphragm pump works orr th e inlet tract of the left top cylinder to pump fuel up from th e tank to the three ca rbs. T he pump must be very well -suited to the demands of th e engine because there is n o header ta n k or overflow re turn to the gas tank. The flow to the float bo wls , is co ntrolled jus t J by the .nor... _ ...... • • • I I _ J:;' ." . I " ~ J I .J •

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