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September 16th, 2017

Building and working on a motorcycling idea is largely as enjoyable and involving as riding that motorcycle when it’s finished. And when you have the freedom (read budget) and support from a French petroleum giant and a steady job revolving around developing and designing Formula One cars, there is very little scope to complain. Welcome then one of the most interesting motorcycle development programs in the history of two-wheeled motorsport, the ELF X and the man who was responsible for its design and development, Andre de Cortanze. Through the 60s and 70s era, many top brands from various businesses like tobacco, liquor, clothing and petroleum powerhouses reaped solid benefits marketing their products in motorsport. ELF Petroleum was one such outfit too.

As ELF build upon a successful partnership with Renault motorsport, the petroleum giant decided to expand and develop a radical new endurance racing motorcycle that would go on to introduce the world to newer fundamentals of motorcycle engineering in the years to come. ELF’s marketing top man, Francois Guiter, was convinced that a winning machine flaunting the ELF colours would be a definite marketing strategy that would bring in sales numbers to his company. And thus in 1978, began a decade-long program of developing a radical endurance racing motorcycle.

The idea was to build a motorcycle where the engine would be a part of the chassis and not a separate unit. What today we know or refer to as ‘engine as a stressed member’. Unlike the old designs where the engine would be plonked inside a frame designed for the motorcycle. While using the engine as a stressed member was seen in Formula one cars previously, it wasn’t so common in the world of motorcycle racing. de Cortanze wanted to completely do away with a separate chassis and build a machine where the engine handled the chassis duties as well, hence helping him to reduce weight and achieve better rigidity for better handling.

Honda Elf Prototype


And with his extensive work and research in racing vehicle development with Renault, he had a fair bit of idea on how he was going to achieve that on the ELF X – the ‘X’ here standing for ‘Experimental’. The motor was taken from the mighty (and still mighty) Yamaha TZ750 inline-4 2-stroker, (remember the famous quote by King Kenny Roberts “They don’t pay me enough to ride that thing’? Yes that motorcycle!). Building an endurance racer meant it had to be a fast machine with reliability for long hours and importantly as de Cortnaze saw it, the wheel changes in the pits should be easier and less time consuming which otherwise was a time-taking effort back in the days. And if he achieved his goals, it could mean critical advantage over the competition in the motorcycle endurance racing scene.

Elf2 Prototype

Under the skin of the Honda-engined Elf


And to achieve that, the conventional telescopic front suspension was replaced by an unusual double-link steering configuration helped by two parallel arms that were connected to the front end of the stressed-member engine. The rear wheel was held in place by a single-sided swingarm, another uncommon technology for its time, attached to the rear of the engine. Employing these methods, de Cortanze was able to attain his objective of rapid wheel changes in the pits during endurance racing. The single-sided swingarm technology later made its foray on Honda’s endurance racing and production motorcycles as well. More on that later though. The ELF X came with a plethora of radical concepts like relocating the fuel tank under the engine to achieve a better centre of gravity in order to improve overall handling on the motorcycle.

Honda ELF E prototype

The Elf E prototype


However, the Yamaha engine failed to comply as a stressed-member despite multiple efforts from de Cortanze and the ELF X project was never fully completed. But throughout its initial development run, it grabbed news and attention of many giants in the motorsport arena, especially of Honda. By the end of 1979 Honda had completed private test session on ELF X with one of their own riders and decided to partner with ELF on further developing the ELF X into an endurance racer, which would later be known to the world as ELFe (e standing for Endurance).

The Japanese giant provided ELF with factory-tuned 1000cc RSC endurance engines (based on the CB900F), which was well suited to the chassis design to be incorporated as the stressed member. From there on the project gathered momentum as the engines worked better than the two-stroke Yamaha motor. And in 1981, Honda entered the World Endurance Championship with the ELFe and continued to participate in the series with the ELFe until the end of 1983. Throughout its participation in the World Endurance Series, the development continued in full steam and Honda claimed several patents under the development including the patent for technologies like the single-sided swingarm design. Sadly, despite its relatively strong performance in endurance racing, reliability was still an issue and the ELFe was withdrawn from the series.

Honda Elf 2 prototype


Later in 1986, there was a streamlined ELF R version made, (R denoting Record), that went on and achieved six world records at the Nardo test track in Italy, piloted by Christian LeLiard, Éric Courly and the iconic Hubert Auriol, (the first racer to win the Dakar Rally in both, bikes and automobiles class. (Read: Hubert’s Dakar Rivalry with Gaston Rahier in rivalries that defined Dakar Rally)

Even though the ELFe did not garner enough endurance racing success, it sure gave Honda an edge over the competition with regards to newer patented technologies and innovations that the Japanese major eventually incorporated in their racing bikes and production models in the coming years. Elf, on the other hand, established itself as a brand that was a powerhouse of technological innovation in motorcycle engineering. Seeing the mutual benefits of both the parties, the partnership continued development and research on the ELF X and the next phase was to build a Grand Prix racing machine based on the ELF X. Following the next few years, the ELF-Honda partnership gave birth to the GP-builds like the ELF2, ELF2A, ELF3, ELF4 and finally the ELF5 in 1988, after which ELF decided to bring an end to the radical project that left a trail of radical innovations in motorcycle engineering in its lifespan of ten years. 

Elf 5 Prototype

Elf 5 Prototype


You can read more about the ELF grand Prix racing machines here (also our sources): Motorcyclist Online, Motorsport Retro, Historic Motorsport Central. Cover Image source.

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