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Source: BMC Braided, automated, optimized a unique radial braiding technology, developed by august Herzog Maschinenfabrik GmbH & Co. KG (Oldenburg, Germany) enables the fabrication of bike frame tubes with varying cross-sections and seamless transitions between locally optimized fiber patterns on this impec racing bike frame, developed by Bicycle Manufacturing Company (Grenchen, Switzerland). Beginning with engineering BMC already had a track record of engineering innovation. Its Advanced Pivot System (APS) is billed as the ���ideal��� rear-wheel mountain bike suspension (see illustration, p. 35), able to deliver the ���perfect��� combination of ef���ciency, power and comfort. Another engineering hallmark is BMC���s Tuned Compliance Concept (TCC), which uses a precise combination of different carbon ���bers and orientations, along with stepped frame tube pro���les, to provide increased ���exibility in vertical components (frame, fork and seatpost) yet maintain high lateral and torsional rigidity. This improves handling and increases comfort and power transmission, slowing the onset of rider fatigue. The perfect racing bike frame, however, would transform all of its rider���s pedalturning energy directly into propulsion with no negative impact from its own weight. In pursuit of that goal, BMC���s impec engineers redesigned each frame tube to optimally perform its unique function in the frame, absorbing and distributing its individual stresses across its entire length, by tailoring both the shape of the tube and the architecture of the composite materials. It turns out that the perfect frame tube is hardly ever round. And, says plant manager Martin Kaenzig, ���We also knew we wanted seamless tubes.��� Tuning the tubes The solution was BMC���s Load Speci���c Weave (LSW) process. This three-stage, robot-controlled production line combines braiding, resin transfer molding (RTM) and trimming into a continuous process. Automated, computer-controlled braiding enables quick and accurate ���ber placement and orientation. Moreover, it can negotiate changes in the cross section of the tube and provide seamless transitions along the tube between ���ber patterns that are optimized for local stiffness and those that are optimized for overall torsional rigidity (see right side of lower diagram on p. 35 and check out ���Learn More,��� on p. 37). january 2013 | 33