The 404’s heritage as Zipp’s icon of speed extends back decades, and its future is even brighter. At 58mm deep, the 404 Firecrest Tubeless is ideal for road races, time trial and triathlon, and gran fondos. The wheelset’s 23mm internal width is perfect for running wider tubeless tires at reduced air pressure. That is a vital component of Total System Efficiency, or TSE, an approach to speed on ever-changing roads and riding conditions. Specifically, TSE focuses on overcoming specific barriers to speed: wind resistance, gravity, rolling resistance, and vibration losses. Zipp’s ABLC Sawtooth Technology uses an intricate dimpling pattern to improve aero efficiency. Zipp’s use of hookless (straight side) rims in the 404 Firecrest is integral to Making You Faster. With hookless, the transition between the tire and the rim is more seamless and aero. Zipp’s hookless rims have more efficient resin distribution, which means lighter, stronger wheels.