It remains 45mm deep, but gets the bulbous Firecrest rim profile that’s 28.5mm at widest and 26.2mm at the brake track. Zipp’s brand manager Andy Paskins says aerodynamics are improved about 8% over the prior model, giving it about a 78 second advantage over a 40km TT compared to a square-ish alloy rim (30mph at 300watts with 15 degree frontal crosswind, if you care)
They’ll be offered with full carbon tubular and clincher rims, making this the first carbon clincher for the 303. Road and CX build are the same, though they get different stickers. We don’t know why either.
The rear hub moves the non-drive bearing outward 7.5mm and cants the spoke flange 8 degrees. The net result is less stress on the spokes and a 7% stiffer wheel laterally. Vertically it remains as compliant as before.
Top radius of rim is very rounded, reducing pinch flats. Aesthetically, there are two new options that replace the silver hub/spokes from this year. The Beyond Black colorway (shown) with black spokes and hub to match the rim. The other is called Falcon Gray, which Paskins said is close to a pewter.
Clincher is just under 1,500g (claimed) and tubular is just under 1,200g. They’re in production now to ship in October. MSRP is $2,700 clincher and & 2,300 tubular. They’ll come with a new brake pad compound called Tangenté Platinum Pro that’ll be silvery. It claims to have stopping power more like rubber pads but with the cooling of a cork pad and not as grabby as yellow pads.