Shimano Dura-Ace 9270 C36 Disc Wheel Rear

The Shimano Dura-Ace 9270 C36 Disc Wheel Rear is the lightest wheel in Shimano's Dura-Ace R9270 lineup, built with climbing as the priority without turning into a wheel that falls apart on the flats. At a 36mm rim depth, it sits well below the deep aero wheels in the range, and Shimano put its weight-savings effort where it actually matters for acceleration: the outer rim. Shimano's own engineering rationale is that rim-level weight accounts for roughly 60% of the energy needed to change a wheel's speed, so trimming grams there pays off more on a climb or a hard attack than trimming the same grams anywhere else on the wheel.

That shows up directly in the numbers. The rear wheel weighs 730 grams, paired with a 620-gram front for a 1,350-gram set — light enough to feel the difference the moment the road tips up. The carbon rim carries a 21mm internal width and 28mm external width, with a hooked tubeless-ready bead, so it works with tubeless setups or with a standard clincher tire and tube if that's what a rider prefers. It ships with tubeless tape and valves already installed, which cuts out one more step before a ride. Despite the shallow 36mm depth, Shimano tested and tuned the rim shape in the wind tunnel, so the wheel isn't just light — it holds a real aerodynamic advantage over an old-school box-section climbing wheel while staying stable in crosswinds and predictable on descents.

The hub is where this wheel picks up its most distinctive engineering. Shimano moved away from the traditional pawl-and-ratchet freehub and built a new Direct Engagement system: a toothed disc freewheel where the hub's toothed disk meshes directly with a matching disk on the freehub body, rather than relying on a handful of small pawls catching a ratchet ring. That toothed-disc interface has a much larger contact area than a ratchet system, which means power transfers more efficiently and the hub holds up better under repeated hard accelerations. It also adds real driving rigidity, so pedaling feels more direct the instant a rider stands up out of the saddle, and the redesign shaves 45 grams off the freehub compared to the previous generation. The hub is built in aluminum, and the wheel uses 24 straight-pull steel spokes on both front and rear, laced with a flat 2.0-1.5-2.0 profile that keeps weight down without giving up spoke stiffness.

All of it adds up to a rear wheel built for riders who want a genuine climbing tool that doesn't need to come off the bike the moment the road flattens out or a group ride turns into a fast, rolling chase. The low weight rewards repeated accelerations and sustained climbing efforts, while the wind tunnel-tuned rim and Center-Lock disc brake mounting keep it composed at speed and in a crosswind on the way back down. Running Shimano's 12-speed road platform, it's built to pair with the rest of a Dura-Ace R9270 drivetrain for riders who've already invested in that groupset and want a wheel that matches its weight-conscious, race-day intent.