Single-speed bicycle on the situation, a messenger may prefer a mountain bike based single-speed, which can roll over many obstacles, or a fast and light road bike-based single-speed. In the United States market, bicycle companies such as Bianchi, Cannondale, Fuji Bike, KHS, Kona, Raleigh, Giant, Specialized, Swobo, Felt, Trek and Niner all have produced and marketed single speed bicycles. Because most full suspension frame designs either have a single pivot that is not concentric with the bottom bracket, or a linkage with a variable center of rotation, the distance between the bottom bracket and rear axle varies throughout the suspension's travel. This
Trek Bicycle Corporation In 1984 Trek ventured into the aftermarket parts and accessories business, launching its Trek Components Group (TCG) department. In 1985, borrowing technology from the aerospace industry, (and bike companies such as Alan and Vitus), Trek introduced its first bonded aluminum bike frame, the 2000. The introduction of bonded aluminum to Trek's production line proved very problematic for a company that had built itself on hand-brazed steel frames. Manufacturing ground to a halt as Trek worked to figure out how to build bonded frames in a production environment. A year later Trek followed up the success of the 2000 with a