For the EDGE program Kestrel's goal was to create an 'epic ride'
full-suspension Kestrel mountain bike, one suited for traversing
extreme terrain on long cross-country rides. IDE's 15 years of award
winning product design brought new ideas and solutions to the EDGE
project. This coupled with IDE's recent Kestrel bicycle design experience
provided an opportunity for IDE to add substantial perspective and
insight to the design and execution of the Kestrel EDGE.
IDE first set out to define Kestrel's vision for the introduction
of a truly fresh image to their line of road, off-road, and triathlon
bicycles. Their previous mountain bikes, the Rubicon and the CS-X,
had performed well both in the marketplace and on the trails.
Nevertheless, in the decade of evolution following their introduction,
the off-road market has evolved dramatically, with new categories
of enthusiasts expecting different forms and levels of performance.
Exploration And Concepts
Of first importance to Kestrel was the
emphasis on "ride quality." A Kestrel bicycle must be strong, stiff,
and use proven geometry, while reducing weight over conventional
3-tubed metal frames. As a kick off to the project, IDE created
several visual panels displaying current dual-suspension bicycles.
IDE then compared them in profile, appearance, price, and share
of the mountain bike market. Additional panels consisting solely
of non-bicycle images (Santiago Calatrava bridges, BMW concept coupes,
extreme technical terrain, and riders) were also presented to Kestrel
in an effort to suggest the future shape of the bicycle, giving
the design team and the engineers a springboard for creative ideation.
It was agreed that the EDGE would have a unique look, with a Kestrel-preferred
"Flash Gordon" aesthetic, while showcasing the use of carbon fiber
weaves.
Several rounds of concept ideation ensued, starting with hand
concept sketches from a team of four IDE designers and immediately
moving to two-dimensional concept renderings in Adobe Illustrator.
IDE then presented Kestrel with a booklet of fine-tuned concept
renderings in time for the 2001 Sea Otter Classic bicycle race
and exhibit. IDE's design team then created large-scale refined
renderings, from which Kestrel was able to decide upon a specific
direction for 3D development. The entire first phase of industrial
design was accomplished entirely using 2D design tools, leveraging
the relative swiftness of image generation and Kestrel's trained
eye for a bicycles' trail-worthiness.
Refinement And 3D Development
3D development began with preliminary surface studies by designer
Sean Horita done quickly in Rhinoceros 3D NURBS surfacing software.
From these surface studies, cross-sections were extrapolated and
transferred to Pro/ENGINEER, where a new set of parametric surfaces
were developed to define the exterior geometry of the frame. The
'hard-points' of the suspension pivots, shock mounts, and all other
frame lengths and angles were adjusted by IDE and Kestrel, taking
advantage of the plastic qualities of the composite construction
and improving on an already efficient suspension scheme. Of particular
challenge was re-creating the hard, "bone-edged" features of the
original illustrations, including the variable concavities running
the length of the top tube and down tube.
Subtle features were integrated into the frame, including a nearly
planar lower surface to the down tube, which reduces mud splatter
in the rider's direction, and intentionally overbuilt "knuckles"
at the head tube, visually and structurally increasing the strength
of this highly stressed junction.
Detail Design And Engineering
The mechanical design for the EDGE started
with a basic geometry layout, which included the wheel base, top
tube, seat angle, and head angle of the two dimensional concept
design. IDE's goal was to make the layout changeable for different
frame sizes, and IDE Senior Mechanical Engineer Niall Macken created
parametric geometry in Pro/ENGINEER so that sizes could be easily
changed. Therefore, Kestrel and IDE could fine-tune any one of the
dimensions and the entire CAD model would update with the desired
geometry. Niall then began building a detailed parametric 3D surface
model, based on the selected ID concept renderings.
To create these kinds of shapes and to make them parametric, thus
able to be modified numerically requires a great deal of skill.
Often, iterative visual modeling is involved when creating some
of these surfaces. The process is a symbiotic relationship between
IDE's design team (industrial designer and design engineer) and
Kestrel, in that at pertinent points in the development process
Kestrel will come in for progress reviews, bringing their many
years of carbon fiber composite manufacturing expertise to the
table.
Each feature of the frame is one step to build in the solids
CAD model, and the 735 different features in the EDGE frame CAD
model are each represented by a line of code in the software.
Therefore, if Kestrel wants a tube, suspension mount, or styling
surface modified it is possible to pinpoint the feature and change
it.
The finished Pro/ENGINEER database was then transferred over
the Internet to a toolmaker overseas, and several completed frames
were delivered within six weeks time. The entire design and development
program took just over six and a half months.
Completing The Design
The EDGE branding and graphic treatment was the product of IDE's
graphic design group. Initial concepts focused primarily on paint
and color schemes with an emphasis on showcasing the carbon weave.
Next, a number of ideas for the EDGE logotype were presented, and
finally all the elements were worked into the final design.
By: Jeff Holcombe
