The zipps are tough enough to excel in the cobbled classics and with the industry's best available braking performance for the most technical descents the 45mm deep 303 NSW is built for a singular purpose: To be fast everywhere. But the 303 NSW is no 'race day only' wheelset to be tucked away in a wheel bag until a race number is pinned to the rider's jersey. It's built to take the abuse of everyday training rides. Zipp has achieved this reliability at a lighter weight with a revised carbon fiber layup developed through testing on the famed cobbles of the Arenberg Forest with the world's fastest riders.