The Fast Forward F9R Carbon Tubular Wheelset is the ultimate Time Trial and Triathlon carbon wheelset with the aerodynamic DARC technology. The 90mm deep carbon rims are the best choice for triathlon and time trials where maintaining speed is key. FFWD DARC stands for ‘Double Arc’ which is the profile of the rim. It compresses air on the rim to create a faster airflow which reduces the drag behind the wheel. The FFWD Hubs are based on price and quality. High-end hubs with the least rolling resistance keep on going when you give them a spin.