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Brave New World
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Bimota Tesi 2D & Vyrus 985 C3 4V
Jeff Buchanan
11/01/2006
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Photography by Cordero Studios/corderostudios.com
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In the inexorably pragmatic world of science, any new concept that dares
contradict the norm immediately comes under intense, unforgiving scrutiny. New
inventions, however enthusiastically received, tend to burn through the
honeymoon of their introductions with great alacrity. They are either welcomed
as viable alternatives and spark new waves of discovery, or are so rudely and
harshly quashed as to remove any residual hope of their resurfacing in the
future. Science demands results and suffers fools badly. Of course, also
according to science at the time, the world was flat.
Despite the meteoric
advancements in motorcycle design and engineering, there is one concept in the
annals of motorcycling that continues to intrigue. The concept possesses enough
validity, in theory and practicality, to prevent it from being permanently swept
under the proverbial rug of invention, periodically resurfacing in various
incarnations in the decades since its initial invention. The fact that it has
yet to succumb to any substantive lambasting or lasting, damning ridicule by the
experts, suggests there just may be something to it. The enigma that refuses to
go away is hub-center steering.
Hub-center steering is a creative alternative
to an inherent engineering challenge in the traditional, accepted design of
modern motorcycles that employ a telescopic front fork. In this common, almost
standardized configuration, the front fork is required to perform two
dramatically opposed functions: provide suspension for the front wheel and
facilitate steering. Ultimately, in basic engineering principles, relying on one
design element to provide two contradicting functions results in a
compromise of optimum performance for both.
 Although several manufacturers
have dabbled with hub-center steering, scarce few have actually entered mass
production. Certainly, most notable is Italian marque Bimota, virtually branding
itself the faithfulpur-veyor of hub-steering design since astonishing the press
at the 1983 Milan Motorcycle Show with their innovative Tesi. Yamaha entered the
fray in the early ’90s with its impressive single-sided front swingarm,
hub-steered GTS1000 sport/tourer. Despite mostly favorable performance reviews,
sales tanked and the project was abandoned. Elf Racing campaigned a prototype
hub-steer road racer for several seasons with a modicum of success, but that was
purely developmental and never reached the public. (Click image to enlarge)
Today, there are two
companies selling hub-center steering motorcycles—the aforementioned Bimota, and
another Italian company, Vyrus Consultancy. Both of them sell hub-steer machines
that mimic the original Tesi design platform. The Vyrus project was born as an
independent endeavor, championing the Tesi design when Bimota fell on hard times
and ceased production of its own machine. Vyrus continued to develop and refine
the unique chassis, keeping the flame of hub-steer ingenuity from being
extinguished. The work of Vyrus impressed Bimota. When the Bimota re-entered the
market, the company contracted Vyrus to build its Tesi chassis.
 Bimota’s
Tesi 2D utilizes a Ducati L-twin, air-cooled, two-valve Desmodromic 992cc
powerplant, whereas Vyrus tenders two powerplant variations—the 985 C3 4V,
equipped with Ducati’s liquid-cooled L-twin, 999cc four-valve engine, plus the
984 C3 2V fitted with the same powerplant as the Bimota. Both machines are
brimming with awe-inspiring, avant-garde presence—regardless of the beholder’s
personal stance on their function or looks. (Click image to enlarge)
Over the years, there have been a
number of experiments with regard to alternative motorcycle front ends, from
leading and trailing links to girders and parallelogram designs. There was the
Neracar of the 1920s (the first production example of hub-steer motorcycle
technology) and, most recently, BMW’s current Telelever front suspension system.
Engineers continue to explore paths to advance this aspect of motorcycle design.
However, the majority of these concepts—with the exception of the Neracar and
Tesi—are based on traditional steering fork designs and were primarily concerned
with eliminating the effects of front-end dive, the resulting action of
compressing a telescopic fork under braking.
Perhaps what makes the hub-steer
project so interesting is that it is such a drastic departure from the
traditional steering fork concept. As odd as the design may appear, it
actually represents a sound, practical approach to basic physics. The Tesi
project came out of the open minds of two students at the Plolitecnico of
Bologna in the early 1980s. Engineering hopefuls Pier Luigi Marconi and Roberto
Ugolini met with legendary designer Massimo Tamburini—who was
then Bimota’s technical director—seeking insights into furthering future
design elements. It was Tamburini who pointed the students toward the front
axle of traditional motorcycle construction as representing the greatest
opportunity for change and development.
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