Duke Sierra Æra SLR5 | Aero Carbon Gravel Rim | From 390 g

Aerodynamics That Work for Your Speed

As speed increases, aerodynamic drag becomes one of the biggest factors affecting riding efficiency. The Duke Sierra Æra SLR5 series has been developed for riders who want to maintain a high pace over long distances while preserving the comfort and confident handling that made the original Sierra platform so successful.

Using Computational Fluid Dynamics (CFD) together with Duke’s Æra Technology, each rim profile has been optimised to improve airflow around the rim and modern high-volume gravel tyres. The result is lower drag, greater crosswind stability and improved efficiency whenever speed becomes the priority.

The Same Platform. A New Level of Performance.

Sierra Æra is built on the same SLR5 (Super Light Series 5) platform as the Sierra range. Toray T1100 carbon fibres, aerospace-grade resin and an optimised carbon lay-up create rims that combine low weight with excellent stiffness and long-term durability.

Despite their advanced aerodynamic profiles, Sierra Æra rims remain remarkably lightweight:

• Sierra Æra 48 – 390 g
• Sierra Æra 56 – 410 g
• Sierra Æra W42 – 420 g
• Sierra Æra W48 – 460 g

These weights preserve quick acceleration and climbing efficiency while delivering aerodynamic gains that become increasingly noticeable at higher speeds.

The combination of low weight and advanced aerodynamics allows Sierra Æra to maintain higher average speeds with less effort, without compromising comfort or predictable handling across mixed terrain.

Wide Technology – Aerodynamics for Modern Gravel Tyres

The Sierra Æra range includes both conventional aerodynamic profiles and models featuring W (Wide) technology, developed specifically for today’s wide gravel tyres.

On the W42 and W48, the 43 mm external rim width creates a smoother transition between the rim and tyre, reducing airflow separation and improving the aerodynamic efficiency of the complete wheel system.

This approach allows riders to benefit from modern high-volume gravel tyres without sacrificing aerodynamic performance.

Comfort Without Sacrificing Speed

Aerodynamic wheels should never come at the expense of comfort. DRC (Dynamic Response Comfort) technology filters vibrations from rough terrain, improving grip while reducing rider fatigue during long rides. Whether you’re riding fast gravel roads or more technical sections, Sierra Æra delivers confident handling and predictable control.

Engineered Down to the Smallest Detail

Every Sierra Æra rim incorporates technologies developed by Duke to maximise performance and long-term reliability.

• SLR5 (Super Light Series 5) – advanced lightweight carbon construction using Toray T1100 fibres and aerospace-grade resin.
• Æra Technology – CFD-developed aerodynamic rim profile that reduces drag and improves crosswind stability.
• SpokeCore – moulded spoke holes create a more homogeneous rim structure and optimise load distribution.
• Offset – asymmetric rim geometry balances spoke tension, increasing lateral stiffness and steering precision.
• AntiPinch – specially shaped rim beads help reduce the risk of tyre cuts caused by hard impacts.
• VFP (Varnish Free Process) – a clearcoat-free finish that reduces weight while improving surface durability.
• Hooked / Tubeless Ready – full compatibility with modern tubeless systems and clincher tyres.

Designed for Modern Gravel Riding

Sierra Æra rims are engineered around modern gravel tyres between 40 and 45 mm, while remaining fully compatible with tyres from 36 mm up to 2.4”.

The wider rim profile provides better tyre support, allows lower tyre pressures and improves comfort, grip and control. On the W42 and W48, Wide Technology further enhances the aerodynamic integration between the rim and tyre.

Four Profiles. One Philosophy.

Every Sierra Æra model shares the same advanced SLR5 platform while offering a different level of aerodynamic performance.

Duke Sierra Æra 48 – 390 g
The lightest model in the Sierra Æra family. A classic aerodynamic gravel rim that perfectly balances low weight, aerodynamic efficiency and all-round versatility for fast gravel riding and racing.

Duke Sierra Æra 56 – 410 g
The most aerodynamic model in the Sierra family, developed for maximum efficiency on gravel races, exposed roads and high-speed riding.

Duke Sierra Æra W42 – 420 g
The most versatile model featuring Wide Technology. Its 43 mm external width and aerodynamic profile are optimised for modern wide gravel tyres, combining speed, comfort and stability.

Duke Sierra Æra W48 – 460 g
The most advanced Wide Technology model. Its deeper profile and 43 mm external width maximise aerodynamic efficiency while maintaining excellent stability and predictable handling at high speeds.

Whichever model you choose, Duke Sierra Æra SLR5 is built on the same advanced technology platform, combining lightweight construction, modern aerodynamics and the comfort required for long days on gravel.

Sierra was created to be as light as possible. Sierra Æra was created to turn that lightness into even greater speed.