DUKE Sierra Æra W42/48 Wheelset

Description

If the W48/56 is DUKE's answer to flat-out gravel racing, the Sierra Æra W42/48 is the version for everyone whose rides don't come with a race number every weekend — but who would still rather be faster. Same Toray T1100 carbon, same SLR5 process borrowed from DUKE's most advanced mountain bike rims, same hand-built care from a French workshop with 18 years of custom wheelbuilding behind it, in a front/rear pairing that trades a little top-end depth for wheels that disappear beneath you on any terrain.

The front is the interesting one. At 42mm deep and a very wide 43mm external, the W42 is shaped so its sidewalls sit flush with a 40–45mm gravel tire. DUKE's CFD work shows the tire-to-rim transition matters more than raw depth, so the Wide rim buys aero efficiency without the wind exposure of a deeper wheel. The 48mm rear takes the conventional profile, since the air back there is already scrambled by rider and drivetrain, and a touch more depth adds inertia for holding speed. Over both runs the Æra signature relief — the repeating micro-profile you can see in the carbon — which reorganizes airflow to cut drag by up to 10% versus a smooth rim, with no loss of composure in crosswinds.

Underneath, it's a proper gravel chassis: 28mm internal width sized for modern rubber, SpokeCore molded spoke holes that never puncture the carbon layup, DRC damping that filters chatter on broken surfaces without dulling accelerations, and an AntiPinch bead that tolerates low pressures and hard hits. The varnish-free VFP finish is lighter, tougher, and cleaner to produce than paint. Every set is hand-built to order: choose DUKE's own Mad Max hubs (from 1,351 grams the pair) or Tune's Nano hubs, with Sapim CX-Ray spokes standard and Tune's CxCarbon spokes available on the top build, plus a freehub body for every drivetrain — XDR, HG11, N3W, or MicroSpline. Tape and valves are in the box; tubeless or tubes, your call.

This is the set we'd point most fast gravel riders toward: rolling courses, mixed surfaces, long days where efficiency accumulates. And if you're looking for a fully custom build around these rims — spoke counts, decals, a hub we don't list — reach out for a quote.