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Sometimes a new product comes along that improves upon a few aspects of its predecessor. And sometimes a new product gets completely reinvented, made better in almost every way. The Zipp 303 S is in the latter category. It shares the same 45mm rim depth, but that’s where the similarities end.
Images courtesy of Zipp
The 303 S features an entirely new rim design that accommodates the move toward wider, tubeless tires. Measuring 23mm internally, 7mm wider than before, this rim is optimized aerodynamically for the lower rolling resistance of 28mm tires. Zipp’s testing shows a 10-watt savings compared to a top peer wheel in total power required to ride 40kph on a flat road with a 28mm tire. A new hookless rim allows for a seamless transition to the tire, helping reduce drag and achieve those aero benefits. That hookless rim design also means this wheel is compatible with tubeless tires only. You can throw a tube in as a roadside repair, but the tire will need the stronger bead of a tubeless ready tire to be compatible with the hookless profile.
Because this rim is wider, it can also support up to 50mm wide tires, more than plenty to do double duty as a gravel wheelset. On the opposite end of the spectrum, 25mm is the minimum tire size.
Even while getting a wider rim shape, this wheelset has lost a significant 155 grams compared to the 302, bringing the total down to 1,540 grams. But maybe the best part is the price: $1,300 for the set. That’s $200 less than the 302 for a set that is lighter, faster and more versatile. And one that comes with a brand new look and lifetime warranty against manufacturer defects and impact damage during intended use.
The 303 S is disc only and 700c only. If you want 650b or rim brake wheels, you will have to look elsewhere in Zipp’s line.
More info: zipp.com