Shimano Dura Ace WH-R9370 C99 Disc Wheelset

Developed with WorldTour pros and triathletes under Shimano’s “Science of Speed” philosophy, the WH-R9370 series improves on weight, aerodynamics, stiffness, and maintenance versus the previous generation. All models are optimized for 28–30mm tires and feature a redesigned hub with replaceable cup-and-cone bearings.

WH-R9370 Disc (TT/triathlon rear wheel):
Developed specifically with pro triathletes for maximum aero efficiency in time trials and triathlon
Rim shape and profile based on 30+ billion simulations for exceptionally low drag
Closed, full-disc construction reduces turbulence for outstanding efficiency

Aerodynamics:
23mm inner width, 29.4mm outer width — optimized for wide (28–30mm) tires
Developed via flow simulation and real-world testing, including realistic approach angles, not just ideal wind tunnel conditions

Hubs:
Retains proven cup-and-cone bearing system, now with replaceable bearings for easier maintenance
~30% less rotational friction than conventional industrial bearings (per Shimano’s comparative testing)