b'Consumer Goods | Engineer InnovationTrek BicycleDesign space exploration enables optimization of bicycle aerodynamics and ride qualityDesigning second-to-none bicycles traditionally known for their harsh rides Trek Bicycle Corporation is an Americanand poor handling, Trek notes.manufacturer of bicycles, cycling components, accessories and apparelAttacking this challenge in developing its whose founders set out in 1976 to makeMadone road bike, Trek applied the best bicycles the world had evercomputational fluid dynamics (CFD) seen. The companys vision wastogether with finite element analysis grounded on two principles: the product(FEA) to set a new benchmark for would be of the highest-qualityaerodynamics in a bicycle thats also craftsmanship, and it would bring the joycomfortable to ride and handles of cycling to a broader audience.smoothly. Aerodynamic performance is Propelled by this vision, Trek is now onemost influenced by the geometry of a of the largest bicycle manufacturers inbicycles tubular frame. Aerodynamic the world, employing almost 2,000tube shapes typically have high aspect people and producing about 1.5 millionratios, where the depth of the tube is road, mountain and city bikes each year. two to three times greater than the width. This provides for a very While not everyone may think of bicyclesaerodynamic profile, but the large as high-tech products, bike designsection properties resist bending, like an involves complex physics and frequentlyI-beam, creating a harsh and unforgiving unknown interactions among multipleride. To overcome this conflict, Trek physical phenomena. A key challenge isengineers hit on the solution of the trade-off between aerodynamicseparating the aerodynamics from the efficiency optimization and comfort andcomfort with a tube-in-tube ride quality. Aerodynamic bikes areconstruction. This new way of designing a frame allowed them to design an outer tube structure optimized for aerodynamics with Kammtail Virtual Foil (KVF) tube shapesan aerodynamic airfoil design that originated in the auto racing world. Meanwhile, an inner tube structure was optimized for ride comfort by FEA-based tuning of deflection and vertical compliance. These are the properties by which the frame cushions the rider from vibration and road surface irregularities.Automating workflows for bicycle design A few years ago, Trek engineers began seeking a tool to automate their search for optimized frame designs. They needed a solution that would be compatible with their existing computer-aided engineering Figure 1: The Madone, the ultimate bike, a fusion of power, aerodynamics, ride quality and(CAE) softwareSimcenter STAR-CCM+ integration, was designed using Simcenter STAR-CCM+ and HEEDS for CFD and Abaqus for FEA, as well as 29'