Carbon fiber is renowned for its outstanding stiffness, vibration-damping ride quality and out-of-this-world lightness. However, it does not have as much impact resistance as aluminum. Zipp solves this issue and furthers their reputation for making some of the world's best functioning wheels with their Carbon Bridge technology. Kevlar threads woven through the carbon in the prime impact zones boost the rim's impact strength by an outstanding 28%. Carbon Bridge technology means you can ride your Zipps for years to come over the roughest roads with the confidence that you have some of the fastest and strongest wheels going.