Even with all the recent refinements and additions to the Zipp product line, the 404 (58mm) wheel is still the Champ This versatile wheelset has reigned supreme in World Ironman Championships, numerous CSC and Phonak Tour de France stage victories, and countless personal bests all over the world in every cycling discipline. Don't let those good looks fool you: the patent pending aerodynamically dimpled pattern is an extremely ruthless controller of air resistance that delivers an average gain of 1 to 4 watts of energy in very nearly all conditions and races. Triathlon, road racing, sprinting, time trials - you name it, 404 is the universal master that has earned its place as our top performer and the choice of elite cyclists everywhere.