SUNCORD 4-7 Speed Carbon Tensioner for Brompton Bicycle C Line

1. The adapter base uses a single bearing aluminum alloy design, while the swing arm is made of carbon fiber to prevent the chain tensioner from deforming when the metal swing arm folds and the chain drags. Carbon fiber offers better elasticity and resistance to deformation.
2. The main body of the pulley is made of plastic carbon fiber with dual-sided carbon fiber covers. The pulley teeth are designed with 10T or 12T positive and negative teeth, made using imported racing-grade steel and full CNC processing, which reduces chain noise.
3. The pulley operates in a linear motion, using a single plastic linear bearing and a black ceramic rod.