Develop a carbon fiber version of GT’s already successful aluminum LTS mountain bike using thermoplastic carbon fiber material and manufacturing methods that could compete with other bikes coming out on the market.
For those of you who do not know this bike, we are climbing into the way back machine of bike design for a trip to the mid 90’s. While carbon fiber had been used in bike designs before this time by companies like Kestral, the material was starting to make its move toward being mainstream.
Development began with pencil sketches of several concepts for the consideration of management, manufacturing and product managers. From there, several of the concepts were chosen and made into full scale wood prototypes to better understand the shapes and real-life appearance of the designs. As we continued down this course there were some realizations which led to improvements in the manufacturing process that would create a better product. This entailed the addition of aluminum lugs where the crank, steerer tube and seat tube interfaced with the frame. These lugs provided a better fit to the components and a better manufacturing process where a single carbon fiber roll was routed through the lugs instead of multiple rolls being used to create the frame. This new approach necessitated going back to the drawing board and starting fresh again. The fresh start did not reset the clock on the schedule so there was little time to get a new design done. We pushed through with a very simple and incomplete sketch, built a wood prototype that did not even get painted and jumped right into making molds for the different sizes and getting the lugs machined.
In the end, design of the bike was well received. The high contrast of both color and material between the black carbon and the raw aluminum was very eye catching. It still managed to have places for 2 water bottles which was a complaint back then about some other designs. We were also able to run the cables internally which added to the clean look of the bike. While the design did well, the choice of thermoplastic as opposed to thermoset caused issues when the bikes were exposed to high heat situations. Over time the processes improved for thermoset over thermoplastic and the ability for the bike to remain competitive faded. But this is also the current case with the bike market; the best designs are eclipsed within three years by better, lighter, quicker and more comfortable designs.