What is CiR, and how is it used in Zipp 858 NSW Tubeless disc brake wheels?

CiR, or Carbon internal Reinforcement, is Zipp’s new NSW laminate technology.  Most carbon rims have uniform thicknesses around the rim, but the forces exerted on the rim are not uniform. CiR places the carbon fiber precisely where it is needed, and nowhere else. Our Engineers have been working for more than 2 years to accurately place the optimal amount of carbon to create the lightest possible rim that still passes our very stringent internal testing plan.  CiR allows us to see a 10% weight loss from our previous laminates with the same stiffness, strength, and durability.  The net effect is a lighter rim. There will be sections of the rim sidewall that are more flexible than others; this is by design.  This is part of how Zipp makes you faster.