ELF Racing - ELF Motorcycle Chassis Designs -
Retrospective
Tracing A Decade Of Radical Racebike
Experimentation
By Alan Cathcart
The waving of the checkered flag at the Brazilian
Grand Prix on September 17, 1988, marked the end of an era. A decade of exciting
experimentation came to a close that day when the last ELF racing motorcycle
completed its final race. In the 10 years leading up to that day, the ELF name
had transcended its petroleum-industry roots. It had become synonymous with a
series of ambitious, high-profile and determined attempts to expand the
frontiers of motorcycle chassis design. ELF created an alternative motorcycle
that would demonstrate its superiority on the most demanding proving
ground-international roadracing competition.
ELF wasn't the first to experiment with
alternative motorcycle chassis designs, but it was the best publicized and,
thanks to the French petroleum company's vast resources, the best funded, too.
Even if its two-wheeled experiments didn't radically alter motorcycling's
future, ELF made chassis experimentation respectable. Inspired by ELF, countless
designers the world over were encouraged to create the motorcycle of the future.
ELF may not have been the first to dream up some of the ideas it subsequently
claimed credit for (and patented to recoup some development costs by selling
them to Honda), but it legitimized the effort. The actual design solutions ELF
evolved over the years were overshadowed by its influence over motorcycle
design. Thanks to its involvement in world championship roadracing, the
alternative motorcycle design is more of a reality and less of a dream.
ELF has a long history of supporting new
motorsports technology, and leveraging that support to build its brand. ELF
sponsored Renault in the 1970s, when the French automotive giant introduced
turbocharging technology to endurance racing and then to F1. Andre de Cortanze,
one of the leading Renault designers during that period, came up with the A442
Alpine-Renault V6 turbo that won the Le Mans 24 Hours, and also developed
Renault's first turbo GP racecar. An enthusiastic enduro rider on two wheels, he
was also full of avant-garde ideas on motorcycle design, many of which
incorporated lessons learned from the racing car world. Sharing these in
conversation with ELF's marketing boss Francois Guiter during breaks in testing
Renault, de Cortanze was eventually entrusted with a small budget for a
motorcycle prototype to test his ideas. Thus the ELF motorcycle project was
born.

The subsequent Yamaha TZ750-powered ELF X (for
experimental) appeared in unfinished form at the 1978 Paris Show. The machine
incorporated many of de Cortanze's principal design aims, which he summarized
thusly: "I wanted to get rid of every preconceived notion I had of what a
motorcycle should consist of and look like," he explained. "I wanted to achieve
four aims: lower the center of gravity, incorporate 'natural' antidive
suspension, reduce weight and eliminate the chassis completely as a separate
entity. There were secondary objectives: to achieve an ideal 50/50 weight
distribution, lower the frontal aspect to reduce the drag coefficient (Cx) and
be able to change wheels quickly. I also hoped to improve airflow to the
radiator for more effective cooling, and make the suspension and steering
geometry adjustable quickly and easily in a way that we had begun to accept as
normal on racing cars but which was largely unavailable then on bikes." De
Cortanze was nothing if not ambitious.
The ELF X, built in de Cortanze's spare time at
Renault with its passive blessing, established many of the design features that
would become his signatures in future years. Parallel arms replaced a
conventional front fork, and a single-sided swingarm held the rear wheel. The
chassis was essentially deleted. The arms were mounted to plates bolted to the
stressed-member engine. The fuel tank was located beneath the engine, and
wind-tunnel-designed bodywork maximized aerodynamic efficiency. The ELF X was a
fundamentally radical racing machine.
Michel Rougerie undertook initial track testing
in 1978, prior to its racing debut at Nogaro later that year. But development
was slow, hampered by problems with a Yamaha two-stroke that proved unsuitable
for use as a fully stressed member, and de Cortanze's part-time involvement. But
ELF X made a sufficient impression for none other than Honda to express
interest. A private 1979 test session with a Honda test rider confirmed that
interest. Soon a collaboration was launched between the Japanese manufacturer
and the French fuel giant. Honda agreed to supply ELF with works 1000cc RSC
endurance engines for the 1980 season, around which de Cortanze would build an
all-new bike incorporating the lessons learned on the ELF X.
The result was the ELFe (for endurance) that
debuted at the 1981 Bol d'Or and, with substantial ELF backing, competed in
every round of the World Endurance Championship until the end of 1983. Though
the ELFe was very fast, often qualifying on pole and leading early laps, the
chassis was unreliable. Refined to the purest form of de Cortanze's ideas, it
finished third in the final 1000cc TTl/Endurance race at Mugello in 1983, then
captured six world-speed records at Italy's Nardo test track in 1986 in ELF R
(for record) form, fitted with special streamlining.
The end of one-liter endurance racing at the end
of the 1983 season enabled ELF to enter the higher-profile world of prototype GP
racing and reap better promotional dividends. Honda supported them with
three-cylinder RS500 engines, and in June of 1984 the ELF2 began testing in the
hands of de Cortanze's longtime collaborator, Christian Leliard. Its most
interesting feature was a revolutionary steering system, consisting of
handlebars mounted to a crossmember and rigged to move fore and aft, rather than
pivoting side to side. The suspension was also adventurous, utilizing a pair of
specially made Marzocchi shocks beneath the engine that worked in traction
rather than in compression.
The Black Bird, as it was dubbed by the French
press, never raced. Riders found the curious steering system hard to get used to
(push-starting on a crowded GP grid would have been exciting!). The proximity of
the suspension pivots and insufficient damping from the special Marzocchis led
to incurable handling problems. It didn't debut until a year later at the French
GP at Le Mans, by which time it morphed into the less-quirky ELF2A, with proven
ELFe-type hub-center steering and revised suspension.
At this point de Cortanze was forced to give up
his involvement with the ELF project, which had been dwindling due to the
pressure of his new job with Peugeot. Guiter entrusted the next stage of
development to race manager Serge Rosset, who had been running a pair of NS500
Honda triples in ELF colors while waiting for the ELF2, and engineer/draftsman
Dan Trema. Guiter and ELF management were hungry for results. With this in mind,
Rosset and Trema collaborated on the relatively conventional ELF3, powered by
works Honda NS500 engines. British rider Ron Haslam, fifth in the World
Championship the previous year, would ride it.
Rosset's
commitment to produce results had immediate effect. Haslam used the ELF3 to
score ELF's first 500cc World Championship point in its first race at Jarama
in 1986. Haslam was a superb test rider, forging an unlikely but lasting close
relationship with Rosset. In the hands of this Anglo-French alliance the ELF3
progressed quickly, winding up ninth at the end of the season ahead of the
works Suzuki team. The breakthrough had been made: Here was an alternative
design that worked as well as a conventional one right out of the box, with an
entire development cycle ahead.Honda agreed,
signing a secret 1985 agreement to evaluate ELF's patented designs with an eye
toward production applications. Commercial negotiations to lease the patents
began, and an agreement was signed in September 1987. The first Honda to
incorporate ELF's patented single-sided rear swingarm (henceforth dubbed
'Pro-Arm') had already been introduced to the market. Trema holds the
distinction of being the first outsider to spend a fortnight working inside
HRC. He visited there late in 1986 to design parts for the new ELF4 and to
work on the NSR500C V4 engine. Delays meant Haslam started the season riding a
standard NSR Honda in ELF colors, but he finished fourth in the 1987 points
table though he only rode the ELF4 in the final few GPs. Serious brake
problems delayed the bike's race debut. A proposed carbon-fiber chassis was
rejected after laboratory tests showed its failure to meet minimum safety
standards.
Instead, Rosset and Trema redesigned the V4 ELF for
1988. That was the final year of the ELF bike project, at least partially
because of concept champion Guiter's imminent retirement. Employing a
cast-magnesium chassis and Honda-supplied Nissin front brakes, the ELF5 worked
well enough, but the conventional opposition had become stronger and more
sophisticated. Three seventh places and 11th in the points standings were the
fruits of its disappointing final season; an anticlimactic end for a project
that had promised so much and actually delivered such useful technology.
In the end, the ELF roadracing effort went out with a
whimper instead of a glorious bang. But there was one race victory in the 1986
Macau GP, on a circuit where Ron Haslam is the acknowledged master, to point
to as proof that the unconventional motorcycle really did work. Honda
obviously thought so too. Every Pro-Arm-equipped VFR Interceptor that rolls
out the door reminds us of this fortuitous collaboration. Who are we to argue
that?

The final edition
Riding elf5,The End of This Innovative Line
The ELF5 that carried Ron Haslam to 11th place in the 1988 500cc World
Championship (sevenths at Spa and Brno were his best results that season) was
the ultimate expression of the project's design philosophy. I had ridden most
of the previous ELF designs and was keen to sample the last in line. I got my
chance after the 1988 racing season at circuit Paul Ricard during the Au
Revoir les ELF test day. The ELF5 evolved from the ELF3, with a true frameset
and a single horizontal front swingarm using a MacPherson-like strut and
single Showa suspension unit. Team Manager Serge Rosset called this
sophisticated, highly adjustable front-end design the VGC System, for
Variation Geometrique Controle, or controlled geometric variation. To reduce
weight, most chassis and suspension components were made from cast magnesium.
The 1988 ELF5 actually used the 1987 Honda NSR500 two-stroke engine, as the
'88 version wasn't available early enough to allow development of the cast
chassis.
The riding position was more extreme than a conventional
NSR. You sat farther forward to get more weight on the front wheel. On track,
the ELF5 pushed badly, sending me off the outside of the fast sweeper at the
end of the Mistrale Straight and again at the tight left after the Pif-Paf
chicane.
Haslam explained you couldn't ride the ELF5 like a
traditional GP racer, braking late and steering with the rear on the way out.
The ELF5 needed lean angle to turn. When steered like a conventional GP bike,
it felt heavy and unresponsive. But apex the corner in a classical Mike
Hailwood style and steering became neutral, though still heavy. It was stable
but far from nimble, unlike the lighter-feeling ELF3, which felt much more
controllable.
What you got in exchange for heavy steering was
unparalleled braking stability. Because of the hub-center design's constant
steering geometry, you could brake harder and later than on any conventional
machine, and turn under braking without upsetting the handling. Another
advantage of the ELF5 was exceptional chassis adjustability; all the usual
suspension settings, plus head angle, wheelbase, trail, ride height front and
rear, as well as weight distribution were all readily changeable.
It didn't win a championship, but with the ELF5 Serge
Rosset's dream of une moto a la carte-a bike that could be easily altered to
suit the taste of anyone-had been realized. As a believer in the ELF
philosophy from the start, I still can't help but feel a sense of unfinished
business surrounding the concept. As former ELF rider Dave Aldana wrote in a
sidebar to my test of the ELFe back in 1983: "Nice bike, but not done yet."
I'll go along with that.