Gravel wheels face a fundamental engineering tension: riders want aerodynamic efficiency on pavement sections, but they also need a rim profile that accommodates high-volume tires without creating handling quirks in crosswinds. Zipp's 303 XPLR S addresses this with a 32mm external width matched to a relatively shallow 36mm depth—dimensions that let the rim disappear aerodynamically behind 40mm to 50mm tires while keeping the overall profile low enough to remain predictable when gusts hit.

The hookless bead design works exclusively with tubeless tires, establishing a secure air seal without the traditional hooked rim edge. This construction allows Zipp to optimize the internal width at 27mm, giving larger gravel tires a rounder profile that improves cornering grip and ride quality over rough terrain. The wider internal channel also reduces the pinch flat risk that comes from running lower pressures on chunky surfaces.

Zipp developed the rim around their ABLC dimple technology, which they claim reduces aerodynamic drag compared to smooth-surface rims of equivalent depth. The sawtooth pattern disrupts airflow in a controlled way, and while the aero gains matter less on gravel than on smooth tarmac, they're still measurable during the paved sections that connect many gravel routes. The 303 XPLR S sits at the lighter end of Zipp's gravel offerings, trading some impact durability for reduced rotating weight.... Read More