SRAM RED E1 Cassette

The SRAM RED E1 Cassette is SRAM’s lightest and most refined road cassette, engineered for ultra-fast, precise shifting and maximum drivetrain efficiency. Designed for RED AXS E1 systems, it delivers a premium balance of wide-range gearing, tight cadence steps, and race-level durability.

Key Features & Benefits

X-Range Wide Gear Progression
Available in 10-28T, 10-30T, 10-33T, and 10-36T options, the cassette provides a broad gear range while maintaining carefully tuned cog spacing for smooth cadence transitions.

One-Piece X-DOME Construction
Machined from a single steel block, the X-DOME design increases stiffness, improves durability, and significantly reduces weight for race-optimized performance and efficiency.

AXS Electronic Shift Optimization
Each cog is engineered with shift ramps specifically tuned for electronic shifting, ensuring fast, clean gear changes even under high torque loads.

10-Tooth Start for Maximum Range Efficiency
The 10T smallest cog expands overall gear range without requiring larger chainrings, allowing riders to maintain high-speed efficiency while preserving climbing capability.

Flattop Chain Compatibility
Fully optimized for SRAM Flattop chains (D1 / E1), delivering quiet operation, reduced wear, and improved drivetrain longevity.

Multiple Terrain Options (Road to Gravel)
From tight 10-28T road racing setups to 10-36T endurance and gravel configurations, the RED cassette adapts to performance road racing and mixed-surface riding alike.

Technical Specifications

• Drivetrain Compatibility: SRAM AXS 12-speed
• Cassette Range Options: 10-28T, 10-30T, 10-33T, 10-36T
• Driver Body: XDR only
• Construction: One-piece machined steel (X-DOME)
• Cog Material: Steel
• Chain Compatibility: SRAM Flattop D1 / E1
• Shifting Technology: Optimized AXS electronic shift ramps
• Use Case: Road racing, endurance, all-road, gravel performance builds
• Weight: Approx. 180g (varies by range)