Performance Upgrade Made Easy The C38 brings carbon fiber high performance to the real world. It’s a versatile all-rounder equally at home crushing gravel washboards and summiting alpine passes. Optimized for use with modern wide tires, providing the right amount of sidewall support to facilitate surefooted handling in all conditions, the C38 wheelset is a great handling, lively climbing, robust all-road performer that also aerodynamically outperforms many deeper, aero-specific rims that cost twice as much. Carbon wheels are a true performance upgrade to any bike, but too often the price tag puts them out of reach.