In 1988 the NSR V4 500cc-powered machine took to the Grand Prix grid. It was the final design in an intriguing series of bikes begun by Andre de Cortanze – one of the unique engineering brains from Renault’s race department in the mid-1970s. Talk about left-field Grand Prix thinking!
“DUE TO THE DEADLINES IN MAKING THE PATTERNS FOR THE CAST MAGNESIUM SECTION OF THE CHASSIS, A 1987 NSR MOTOR HAD TO BE USED.”
“ANDRE DE CORTANZE BEGAN THE DEVELOPMENT OF THE FIRST ELF – THE ‘X’, IN 1977 AND WAS INVOLVED UP UNTIL HE LEFT THE PROJECT IN 1985 DUE TO HIS WORKLOAD AT PEUGEOT. THEREAFTER THE DESIGNS, WHILE STILL BASED ON SOME OF HIS CONCEPTS, WERE THE WORK OF TEAM MANAGER SERGE ROSSET AND ENGINEER DAN TREMA.”
Starting with the ELF3, the earlier front twin parallel swingarm was dispensed with and a Macpherson strut derived design using a single vertical upright and single horizontal swingarm was used.this was developed into the purposeful unit seen here.
The ELF5 certainly looked the part.the 118kg weight (half wet) and 152hp at 11,500rpm from the 1987 NSR motor provided for a top speed of over 186mph.
Above:the cast magnesium top shock mount also held the instrument bracketry.
Above: Looks sturdy enough! Honda’s Pro Arm swingarm was a lasting result of their collaboration with Elf.
Right:the two twin-choke 36mm Keihin carburettors had been removed at the time of shooting.
Above:the two Nissan four-pot calipers were specially made to Honda’s order after previous years’ brakes had overheated due to being shielded by the front rim, and acted on a pair of close coupled 310mm discs.
Unlike the earlier ELFS up to the 1985 2C, the later Rosset/trema designs used a seperate steel tube chassis that enabled the alloy (cast magnesium for the ELF5) engine support structure to link the front and rear ends.
For such an unconventional design the bike looks extremely clean and purposeful.
Left: Five different grades of cast magnesium were used in the suspension and chassis, which were adjustable for head angle, wheelbase, trail, front and rear ride height and weight distribution, plus the usual rebound and dampening.
Above: Ron Haslam rode ROC-ELFS in the 1986, 87 and 88 500cc world championships, finishing in 9th, 4th (most of the season on a standard NSR as the ELF4 was delayed) and 11th respectively.