ZIPP 303 XPLR S Carbon Rear Wheel B1 Fast, tough and unapologetically wide, the Zipp 303 XPLR S rear wheel brings high-performance gravel technology to riders seeking greater speed, grip and control without stepping up to the premium SW model. The 54mm-deep carbon rim combines aerodynamic efficiency with an ultra-wide 32mm internal profile developed around larger gravel tyres. Increased tyre volume permits lower operating pressures, helping reduce vibration and improve traction across broken roads, loose surfaces and fast gravel tracks. It is Zipp's Total System Efficiency approach applied to terrain where comfort and control are every bit as important as slicing through the air. Key Features High-performance carbon rear wheel for fast gravel riding and racing 54mm-deep rim combines aerodynamic performance with off-road durability Ultra-wide 32mm internal rim width increases tyre volume and support Designed for approved 40-60mm tubeless-ready gravel tyres Hookless Tubeless Straight Side rim construction Lower tyre pressures help improve grip, comfort and control Wide rim profile creates a smooth aerodynamic transition to the tyre Zipp Total System Efficiency design reduces aerodynamic, rolling, gravitational and vibration losses Symmetrical carbon rim profile 24 CX Sprint spokes arranged in a two-cross pattern Durable brass spoke nipples Centre Lock disc-brake fitting 12x142mm thru-axle compatibility Available with SRAM XDR or SRAM/Shimano Road freehub body Covered by Zipp's Lifetime Warranty, subject to its applicable terms and conditions Specifications Manufacturer Zipp Model 303 XPLR S Wheel position Rear Intended use Gravel riding and racing Wheel size 700C Rim material Carbon Rim construction Hookless Tubeless Straight Side Rim depth 54mm Internal rim width 32mm Maximum external width 40mm Rim profile Symmetrical Tyre compatibility Approved 40-60mm tubeless-ready tyres Tyre installation Tubeless with sealant or with an inner tube Maximum tyre pressure 50psi / 3.45bar Brake compatibility Disc brake Rotor fitting Centre Lock Freehub Option SRAM XDR or Shimano Road HG Axle compatibility 12x142mm thru-axle Spoke type CX Sprint Spoke count 24 Spoke pattern Two cross Nipple material Brass Bearings Carbon-steel cartridge bearings Maximum recommended system weight 135kg Compatibility Designed for gravel bikes using a 700C rear wheel, a 12x142mm thru-axle and a Centre Lock disc rotor. Select the freehub option that matches the cassette: SRAM XDR for compatible SRAM XPLR cassettes, or SRAM/Shimano Road for compatible HG-pattern road and gravel cassettes. The hookless rim must only be fitted with tubeless-ready tyres approved by Zipp for use with the 303 XPLR S and its 32mm internal rim width. Compatible tyre widths are 40-60mm. An inner tube may be used inside an approved tubeless-ready tyre, but a conventional non-tubeless clincher tyre must not be fitted. Tyre pressure must never exceed 50psi / 3.45bar, including when an inner tube is installed. The correct operating pressure may be considerably lower and should be selected according to rider weight, tyre size, terrain and manufacturer guidance.