Zipp 1ZERO HITOP SW Disc Brake Centerlock 29" Wheel - Rear

The Zipp 1ZERO HITOP SW Disc Brake Centerlock 29" Wheel - Rear is Zipp's answer to a question a lot of cross-country riders have been asking: why does a fast XC wheel have to feel harsh on rough trail? The rim runs a very shallow 21.1mm depth, a deliberate departure from the deep aero profiles Zipp built its name on, because on singletrack, absorbing terrain matters more than cutting through the air.

That shallow depth is tied directly to Zipp's HiTop compliance technology, a proprietary carbon layup tuned to flex in a way that passes less feedback through to the rider. Where a stiffer XC rim transmits every root and rock strike straight up through the frame, this rim is built to absorb the small, high-frequency impacts that happen too fast for a bike's suspension to fully react to. In practice, that means more traction and composure through chattery, rough sections, and a rider who can carry speed through terrain that would otherwise bounce a stiffer wheel off-line. The rim also uses what Zipp calls a winged design at the hookless bead — a broader profile that gives the tire more surface area to rest against during a hard rock strike, cutting down on the chance of a pinch flat compared to a narrower bead edge.

The rim carries a 30mm internal width and 37.7mm external width, an asymmetrical profile sized specifically around the 2.35 to 2.4-inch tires that dominate current cross-country racing. Zipp built the whole system around bikes running up to 130mm of suspension travel, covering everything from a rigid-feeling hardtail to a short-travel full-suspension XC race bike, which makes this wheel relevant whether a rider's chasing lap times on a smooth course or picking through a genuinely technical one.

Underneath, the wheel runs Zipp's ZM2 SL hubset, an aluminum hub with a six-pawl compression freewheel system that delivers 66 points of engagement — quick enough to matter when a rider needs power down the instant they're back on the pedals after a technical section. The hub uses a Center Lock rotor fixture and is available with a Microspline or XD driver body depending on the drivetrain. Twenty-four Sapim CX-Ray steel spokes lace the rim to the hub on both front and rear, a spoke count and pattern built for a balance of low weight and the stiffness a race wheel still needs at the hub-to-rim interface.

Zipp also builds the 1ZERO HiTop SW around its TyreWiz 2.0 system, a valve-integrated pressure sensor that gives a rider real-time tire pressure data instead of a guess from a squeeze test before the start line. On an XC wheel this tuned to a specific tire width and travel range, knowing exact pressure matters more than it does on a general-purpose trail wheel, and it's the kind of detail that separates this wheel from a simpler carbon hoop. As a complete pair, the 1ZERO HiTop SW wheelset is built light — Zipp lists it around 1,325 grams claimed — while still carrying a 130kg system weight rating, so it's built for racing without asking a rider to baby it on rough terrain.