The new Zipp 303 XPLR SW Wheelset seen in Josh’s review of the new SRAM RED XPLR AXS groupset today is wide and deep for fast gravel riding. The 32 mm inner rim width and deep aero profile claim minimal impacts on aerodynamics when running wider tires that have become common in gravel cycling. Let’s look at all of the specifics below from Zipp.

The Zipp 303 XPLR SW wheelset is Zipp’s fastest gravel wheel ever, thanks to its mega-wide and deep rim that integrates seamlessly with gravel tires.* Current gravel wheels are slightly modified versions of existing road wheels, focusing on high stiffness and low weight. Zipp takes a different approach, solely with speed in mind. In gravel, rolling resistance and vibration loss from rough surfaces, and wind are significant barriers to speed. To combat this, Zipp applied its Total System Efficiency design philosophy specifically to the challenges of gravel.

The 303 XPLR SW is a speed-focused gravel wheel designed with a new approach: Start with the perfect gravel tire and design a wheel around it. To develop this first-of-its-kind wheelset, Zipp engineers learned from studying how gravel racing has changed cycling in recent years, coming to several vital conclusions:

1. The progression of gravel speeds increases the importance of aerodynamic efficiency.
2. Current generation gravel wheels exhibit poor aerodynamic efficiency with gravel tires.
3. Low tire pressures are the key for unlocking speed on gravel, but current gravel rim design provides insufficient tire stance to support lateral cornering loads at lower tire pressures.
4. Current gravel rim designs do not help prevent pinch flats while using lower tire pressures.

Typical tire widths for gravel racing range from 38-50mm with varying tread patterns. Current gravel wheels have an external rim width of 28-30mm, which creates an aerodynamic mismatch when you use a 40mm+ gravel tire. With that narrower rim and wider tire, the tire-wheel interface looks more like the bulge of a lightbulb than the ideal seamless airfoil cross-section. According to Zipp testing, the efficient pairing of wheel and gravel tire of our 303 XPLR SW design provides a 5-watt aerodynamic advantage over a leading competitor. This wheel is optimized for use with the Goodyear XPLR Slick and Goodyear XPLR Inter, both tires designed in partnership with Zipp.

Low tire pressures significantly increases speeds on gravel. The problem with current gravel wheelsets is that a narrow tire bed with low tire pressures will cause the tire to collapse while cornering. The 303 XPLR SW’s wide tire bed increases tire stance, allowing for lower tire pressures without tire squirm under corner loads. That means decreased vibration loss while maintaining predictable control in corners and unbroken traction while climbing. The 303 XPLR SW also helps reduce pinch flats thanks to a rim edge that is 77 percent thicker than previous models, decreasing the chance for damage when the tire bottoms-out on the rim edge upon impact.

What about rim depth? Conventional thinking suggests that shallow rims are best suited for gravel. As gravel racing has progressed, many gravel courses are raced at 35kph+ (~22MPH) with top speeds over 60kph (~37MPH). The 303 XPLR SW rim is 54mm deep to create an effective aerodynamic complement for large gravel tires at high speed. Our research found that a 54mm deep rim creates the perfect aspect ratio for aerodynamic efficiency with a 40mm gravel tire at race speeds.

And while the 303 XPLR SW is built big, it’s a featherweight 1496g to keep you fast up the inevitable gravel climb where group separation often occurs.

Finally, the last critical element in going fast on gravel is the rider itself. You are the veritable engine rocketing across the terrain. The lower tire pressures achievable with 303 XPLR SW will keep you in top condition with less muscle fatigue into the 11th hour by insulating from torturous hours of knocks and bumps. With 303 XPLR SW you’ll fly into the finishing chute more prepared than ever for the final sprint to the line.

*303 XPLR SW IS ONLY COMPATIBLE WITH APPROVED TIRES. The Goodyear XPLR Slick and Goodyear XPLR Inter are specifically designed and optimized for the 303 XPLR SW. Check Zipp’s tire compatibility chart for more approved tires.

Specs

• Wheel Size
700c
• Rim Construction
Carbon – Hookless
• Hub
ZR1
• Rim Inside Width
32mm
• Max System Weight
286lb / 130kg
• Max Tire Pressure
50 PSI / 3.45bar
• Weight(g)
1496g
• Price: $2,200 per wheelset

Features

• Fastest race wheel on gravel, features tubeless and hookless rim profile
• Ultra-wide internal profile for decreased rolling resistance, ability to run pressures under 
30psi (2.1 bars)
• Wide and deep profile integrates seamlessly with gravel tires to increase aerodynamic efficiency
• Applies Zipp’s Total System efficiency to high performance gravel
• Max tire pressure 50 psi/3.45 bar
• ZR1 DB hub is engineered in Germany with better seal design for improved durability and quicker response with 66 points of engagement
• Center locking rotor interface. Lockring is included with the wheels.
• XDR or SRAM/Shimano driver bodies
• Campagnolo N3W Driver body sold separately
• Ships with 12mm front and rear end caps
• Lifetime Warranty

See more at Zipp