FEATURE
P62
BIENVILLE LEGACY V4 PROJECT
justment benefit as winding the
coil springs on a normal fork or
shock up or down, while damper
struts at each end are fully adjustable for both high and low speed
damping.
Using the leaf spring allows
both sprung and unsprung weight
to be reduced compared to a
conventional suspension system,
as well as significantly reducing
the parts count and centralizing mass, while the use of carbon composite material for the
spring both further saves weight
and also enhances longevity via
its longer life cycle compared to
steel, in enduring the constant
flex endemic in a suspension
system, says Nesbitt.
The Legacy gets minimalist
design and is powered by a
1645cc Motus 90-degree V-four
that puts out 161 horsepower.
In addition, employing the leaf
spring permits the use of four
identical carbon fiber suspension
arms front and rear – two to act
as Britten-style girder fork struts
up front, and two at the rear functioning as the swingarm. Each
consists of a carbon fiber structure that's internally braced with
a carbon rod, fitted with 7000 series aluminum caps milled from
solid billet that are bonded on to
the carbon composite, as well as
mechanically attached.
"Imagine the root of a tooth,"
says Nesbitt, "with the carbon fiber acting as the gum – it's the
same format. We have a progressive rate suspension system
based on the same pivot point
front and rear, and there's a titanium rod that connects the two
blades together which pivots on
bearings, so that as the stanchion
with the rear ride height adjuster
rises, it forces the triangle of
the linkage which holds the leaf
spring down. The lynchpin of the
design is really in the front, however. There's a rod that runs concentric with the steering axis to a
pivot point located beneath the
triple clamps. That allows the separation of suspension and steering, which are now completely
