Kestrel EDGE
Creating An 'Epic Ride'
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.
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.
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.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.
