Zipp was founded 20 years ago to produce carbon fibre discs that were lighter and faster than anything else available at the time today the 900 still reflects that commitment to giving you the perfect tool for whatever situation you find yourself in this disc may also be adapted for track use carbon bridge exclusive technology that improves stiffness and impact resistance adding kevlar174 stitched into a 6 bundle co axial thread and placing this at the rim edge allows zipp to 39caps