Yamaha RD56

Works ex­ot­ica

Old Bike Australasia - - CONTENTS -

When Yamaha sent a gen­uine works 250 to Aus­tralia in early 1966, it was a whole new ball game. There had been works bikes in Aus­tralia be­fore; as far back as 1936 Ir­ish su­per­star Stan­ley Woods had brought a rare works 500cc Ve­lo­cette with him on his whirl­wind Aus­tralia tour. A pair of works Moto Guzzis, in­clud­ing the famed wide-an­gle 500cc v-twin, ac­com­pa­nied Fer­gus An­der­son on his 1948/49 Aussie so­journ; reign­ing World Cham­pion Geoff Duke brought two 4-cylin­der 50cc Gil­eras with him in 1954/55, and a year later the Moto Guzzi team of Bill Lo­mas and Dickie Dale had a cou­ple of the all-con­quer­ing 350cc and 500cc sin­gles on which to stir up lo­cal op­po­si­tion on their sum­mer hol­i­day Down Un­der. Tom Phillis and Jim Red­man brought well­worn works Honda 250cc fours with them in 1962 and 1963, but by the mid­dle of that decade, it was Yamaha that was the merg­ing force on the Grand Prix scene. Late in 1965, it was an­nounced that the Yamaha fac­tory, a rel­a­tive new­comer to mo­tor­cy­cle pro­duc­tion com­pared to its Ja­panese ri­vals, would field one of its 250cc World Cham­pi­onship con­tenders for a se­ries of races in Aus­tralia be­gin­ning at the Vic­to­rian TT at Melbourne’s Calder Race­way on Fe­bru­ary 13th 1966. Coin­ci­den­tally, the meet­ing also saw the de­but of an­other works ma­chine – the 50cc Derbi rid­den by fac­tory rider Barry Smith.

The Yamaha coup had been in­sti­gated by Vic­to­rian dis­trib­u­tors Milledge Broth­ers, and the deal was for the Yamaha fac­tory to dis­patch one of the air-cooled disc-valve 250cc RD56 works bikes to Melbourne at the con­clu­sion of the 1965 World Cham­pi­onship at the Ja­panese Grand Prix at Suzuka. By this stage the RD56 was tech­ni­cally ob­so­lete, hav­ing been re­placed by the RD05 V4 at the Ital­ian Grand Prix in Septem­ber. The new V4 was at first un­re­li­able, and Cana­dian Mike Duff scored the fac­tory’s last win for 1965 on an RD56 (pos­si­bly the ma­chine sent to Aus­tralia) at the Fin­nish Grand Prix in Au­gust. The RD56 made its de­but in the fi­nal race of the 1962 sea­son in Ja­pan, and by the time the 1963 sea­son rolled around, power had been in­creased by ten horse­power to 45bhp. It also had seven ra­tios in the gear­box and im­por­tantly, fea­tured a much im­proved frame that was heav­ily in­flu­enced by the Featherbed Nor­ton de­sign. The new ma­chine brought Yamaha its first GP win – the 1963 Bel­gian where Fu­mio Ito led home team mate Su­nako in a fa­mous 1-2 where both lap and race records were smashed. The RD56 recorded a top speed of 140mph on the long straights of Spa-Fran­cor­champs, 10mph more than the best Honda. It could have been the start of some­thing big, but Yamaha were still very short of cash fol­low­ing a failed ven­ture into the scooter mar­ket, and were not seen again un­til the tra­di­tional sea­son-end­ing race in Ja­pan, where they re­cruited Bri­tish rider Phil Read, who led for most of the race un­til the RD56 dropped a cylin­der. De­spite its prodi­gious turn of speed, the RD56 was a fairly con­ven­tional de­sign that had its ori­gins in the RD48 of 1961. It fea­tured an alu­minium al­loy head and bar­rel (each bar­rel with three trans­fer ports) on a ver­ti­cally-split mag­ne­sium crank­case; es­sen­tially two 125cc sin­gles with in­di­vid­ual pressed up crankshafts cou­pled by a cen­tral gear. Bore and stroke were 56mm x 50.6mm. A pump lo­cated on top of the gear­box pres­sure-fed oil to the big end and main bearings through the hol­low crank­shaft. The oil was con­tained in a tank in the

rear of the seat, while the top end of the en­gine was lu­bri­cated by a petrol/oil mix of 25:1. A mag­neto was also sit­u­ated on top of the gear­box, gear-driven from the clutch shaft. In its ul­ti­mate form, the RD56 pro­duced 48bhp at 11,000 rpm and weighed 120kg ready to race. Read brought Yamaha the 1964 250cc World Cham­pi­onship and con­sis­tent re­sults from team mate Duff meant Yamaha took out the Man­u­fac­tur­ers’ ti­tle as well. In 1965, Read and Duff fin­ished 1-2 in the cham­pi­onship, but with Honda now armed with their 6-cylin­der 250, the RD56 was pen­sioned off to make way for the new V4. And so the rac­ing com­mu­nity in Aus­tralia ea­gerly awaited the ar­rival of the works Yamaha, su­per­seded or not. Milledge had signed up young Gee­long rider Alan Osborne in 1964 to ride the exKen Rum­ble Yamaha TD1-A, and he had re­warded them by win­ning the Aus­tralian TT at Calder. Milledge Sales Man­ager Earl Brooks was as­signed the task of look­ing after the RD56 for the du­ra­tion of its stay in Aus­tralia. Yamaha placed strict con­di­tions on what could be touched and what could not. Brooks was not per­mit­ted to work on any­thing be­low crank­case level, as Yamaha sought to pre­serve its disc-valve tech­nol­ogy. Dur­ing its time in the coun­try, the RD56 was in­sured for £12,000, which be­came $24,000 in Fe­bru­ary 1966. Osborne recorded four wins from as many starts in the RD56’s de­but at the Vic­to­rian TT at Calder, but each was hard fought as he strug­gled to get the ma­chine un­der way from the push starts. The Yamaha had been sup­plied with the same ex­tra tall gear­ing as used for Suzuka, and was con­se­quently way over geared for the tight Calder lay­out. The track was also in par­tic­u­larly rough con­di­tion and was com­pletely resur­faced in the fol­low­ing weeks. Osborne strug­gled away last in the 8-lap 250cc TT, only snatch­ing the lead on the fi­nal lap from Doug Sail­lard. It was a sim­i­lar story in the 350cc TT, with Osborne hunt­ing down leader Ron Toombs’ 7R AJS and squeez­ing past for vic­tory. Dick Reid’s Manx Nor­ton kept Osborne hon­est in both the Se­nior and Un­lim­ited TTs, but the re­sult was the same in each case.

Three weeks later, the public road cir­cuit at Long­ford in Tas­ma­nia hosted the 1966 Aus­tralian Grand Prix, in what tran­spired to be the fi­nal ap­pear­ance for mo­tor­cy­cles on the fa­mous track. The high-speed lay­out was cus­tom made for the

RD56 and Alan made short work of both the 250cc and 3500cc races be­fore fac­ing Reid’s Nor­ton in the Se­nior race. How­ever after lead­ing for two laps and show­ing that the 250cc Yamaha had the edge in top speed over the 500 Nor­ton down the 1.5 mile Newry Straight, Osborne felt the en­gine go off-song and he im­me­di­ately pulled out, leav­ing Reid to win from Bill Pound. Var­i­ous astro­nom­i­cal top speeds were quoted for the Yamaha (one news­pa­per stat­ing that it had been elec­tri­cally timed at 166 mph), and Long­ford’s slightly down­hill main straight, at around 1.5 km in length, was cer­tainly con­ducive to rapid mo­tor­ing, but the true speed was some­where near 140 mph, or 225 km/h – as fast or faster than the best of the big Nor­tons or Pound’s Vincent/Nor­ton. With the en­gine re­freshed by Earl Brooks, Osborne was back on the grid the fol­low­ing week­end for the Tas­ma­nian TT at Sym­mons Plains. Smash­ing the lap record set by Tom Phillis on the 250cc Honda-4, Osborne led home Barry Smith’s rapid Bul­taco to win the Se­nior TT, after ear­lier claim­ing the 250cc race. How­ever his colours were low­ered by Barry Smith, who took out the 350cc race when Osborne again had trou­ble get­ting the Yamaha to fire. The year’s premier event was the Aus­tralian TT, held for 1966 at Mount Panorama, Bathurst, and few ex­pected to see any­one chal­lenge Osborne and the works ma­chine. In the 250cc TT, he chalked up Yamaha’s first lo­cal road rac­ing ti­tle (the Aus­tralian TT be­ing the of­fi­cial Aus­tralian Cham­pi­onship in those days), but once again, it was a long and lonely push in the 350cc event be­fore he got un­der way. With his head down, Osborne went through the speed trap on Con­rod Straight at 141mph (227 km/h) but just as he be­gan to chal­lenge Ron Toombs and Terry Den­nehy for the lead, the Yamaha’s en­gine cut out, end­ing his week­end.

There was one more event on the RD56 sched­ule, the Open meet­ing at Oran Park on May 22. De­spite the ab­sence of es­tab­lished stars Kel Car­ruthers, John Dodds and Len Atlee, who were all in Europe, a large crowd turned out but Osborne and the works Yamaha failed to make the grid. In prac­tice, Alan slid down and sus­tained an an­kle in­jury that made rid­ing, and cer­tainly push start­ing, dif­fi­cult if not im­pos­si­ble. Worse still, the Yamaha’s side-mounted car­bu­ret­tor in­gested a help­ing of gravel and dirt, and with the em­bargo on any work within the crankcases, the ma­chine was out of ac­tion in­def­i­nitely. After some months a re­place­ment en­gine was sent from Ja­pan but this was re­port­edly dam­aged in tran­sit and could not be used. The now bat­tle-scarred racer sat around in the Milledge work­shops for the rest of the year and was fi­nally crated up and re­turned to Ja­pan early in 1967. Whether it still ex­ists is un­known, but for a short pe­riod it was the hottest thing to hit the lo­cal scene in many a long day.

Story Jim Scaysbrook Pho­tos Stan Shep­hard, Dar­ryl Brooks, Charles Rice, Col Shee­han.

The RD56 ex­posed. Coils are mounted on the rear frame tubes.

Wide en­gine can be seen in the over­head view.

Push start­ing in the Bathurst pits.

Heav­ily gus­seted steer­ing head on the Nor­ton-in­spired frame.

ABOVE Ex­it­ing the Dip­per at Mount Panorama. LEFT Mag­neto sits above the gear­box.

Round­ing Hell Cor­ner and about to open the throt­tle for the run up Moun­tain Straight at Mount Panorama.

Earl Brooks (over­alls) checks the RD56 dur­ing prac­tice at Bathurst, Easter 1966.

BE­LOW Osborne with the RD56 in the dusty pits at Bathurst.

Ti­died up and with the fair­ing re­painted after the Oran Park spill. Cu­ri­ously, front brake ap­pears dif­fer­ent and rear shocks look like Gir­lings.

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