Dura-Ace C99 WH-R9370-D-TL

The Shimano Dura-Ace WH-R9370 C99 / Disc carbon wheelset is developed for time trials and triathlon, disciplines in which aerodynamic efficiency plays a central role in maintaining speed. It combines the C99 front wheel, with its deep 99 mm rim, and a full-disc rear wheel. Shimano designed this pairing as a dedicated aerodynamic solution for efforts against the clock, particularly when sustaining high cruising speeds over long distances matters most.

At the front, the WH-R9370-C99-TL-F uses a 99 mm deep carbon rim with just 16 Super Aero carbon spokes. Each spoke has an aerodynamic shape measuring 5.2 mm wide and 0.8 mm thick, a configuration intended to minimize drag. Shimano reports running more than 200 million shape simulations during rim development. The front wheel is designed to support efficient riding at speed and has a claimed weight of 788 g, combining the distinctive deep profile with a purpose-built spoke arrangement.

The WH-R9370-D-TL-R rear wheel takes a different approach, using a complete carbon disc structure rather than conventional exposed spokes. Its aerodynamic profile was developed using more than 30 billion shape simulations, according to Shimano, to reduce air resistance. The rear wheel weighs a claimed 987 g. Together, the two individual weights total 1,775 g. The rear hub also features Shimano Direct Engagement, designed to provide a direct response when power is applied to the pedals.

Both wheels offer a 23 mm internal rim width and are designed with 28-30C tires in mind. Their tubeless construction supports a modern tire setup, while Center Lock disc-brake mounts provide the specified rotor interface. Shimano Dura-Ace cup-and-cone hub bearings allow precise adjustment and servicing, and 12 mm E-THRU thru-axles complete the mounting system. With its 99 mm front rim and full-disc rear, the C99 / Disc combination is a specialized choice for riders building a time-trial or triathlon bicycle around aerodynamic performance.