Gravel tire design usually involves picking a priority—rolling speed, cornering grip, or mud clearance—and accepting trade-offs everywhere else. The Zipp G40 XPLR takes a different approach by using a dual-compound construction that addresses multiple surfaces without the usual compromises. The center tread uses a harder rubber compound for lower rolling resistance on packed surfaces, while the shoulder knobs get a softer compound that bites harder when you lean the bike into loose corners.

The 40mm width hits a practical sweet spot for mixed-surface riding. It's wide enough to float over loose gravel and absorb chatter from rough pavement, but narrow enough to fit frames designed around 700c wheels without clearance issues. The casing uses a 120 TPI construction that balances supple ride feel against puncture resistance—dense enough to shrug off small debris, flexible enough that you're not fighting the tire at lower pressures. Tubeless-ready construction means you can run pressures in the mid-20s without worrying about pinch flats, letting the tire conform to terrain rather than bouncing off it.

The tread pattern tells you what Zipp expects you to do with these tires. A relatively smooth center section keeps rolling resistance low when you're on pavement or hardpack, while the ramped side knobs engage progressively as you increase lean angle. The transition feels predictable rather than sudden—you can feel grip building as you push harder into turns. The knob spacing also prevents mud packing in wet conditions, though these aren't designed for sustained mud plugging.... Read More