SRAM RED E1 XG-1290 12 SPEED CASSETTE
The Gold Standard of Gearing.
The SRAM RED E1 XG-1290 is the centerpiece of the E1 groupset, designed to be the lightest and most durable cassette in the SRAM lineup. By utilizing a one-piece machined steel X-DOME design, SRAM has managed to shed weight while significantly increasing the lifespan of the teeth.
The E1 update marks a major milestone for the RED series, introducing the 10-30T and 10-36T ratios to the top-tier range for the first time, ensuring that elite-level weight savings are now available for both pure racers and all-road adventurers.
Understanding the 4 Ratios
10-28T (The Racer): Optimized for flat to rolling terrain where tight jumps are critical. It features at least five one-tooth jumps to help you maintain a perfect cadence during high-speed efforts and sprints.
10-30T (The All-Rounder): New to the RED line, this is the "modern classic" ratio. It provides a slightly easier climbing gear than the 28T while maintaining the tight gear progression needed for competitive group rides.
10-33T (The Alpine Specialist): The go-to choice for riders tackling long, steep mountain passes. It offers a generous "bail-out" gear without creating massive gaps in the middle of the cassette.
10-36T (The All-Road Explorer): The widest range available in the RED series. Perfect for 1x setups or riders who want to tackle extreme gradients and gravel while keeping the weight and shifting precision of a flagship cassette.
Key Features
X-Range Gearing: Designed with a 10-tooth start to provide a wider range and smoother gear progression, keeping you in the right gear longer.
X-DOME Design: Machined from a single block of hollow steel, providing an incredibly stiff platform for instantaneous shifting and maximum weight reduction.
Electronic Shifting Optimized: Specifically engineered with shift ramps designed to work with SRAM AXS wireless derailleurs for the fastest, quietest shifts possible.
XDR Driver Body: Requires a dedicated SRAM XDR freehub body for installation.
Rainbow Colorway Option: Available in a striking iridescent finish across all sizes to match the E1 Rainbow chain.
Technical Specifications
| Feature | Specification |
| Speed | 12-Speed |
| Material | Machined Steel (Cogs), Aluminum (Largest Cog) |
| Driver Body | XDR Only |
| Weight | ~180g (10-28T) |
| Color Options | Silver, Rainbow |
| Technology | X-Range, X-DOME |
✅ Why This IS For You
Performance Weight Weenies: At approximately 180g, this is one of the lightest 12-speed cassettes on the market, making it the top choice for weight-critical builds.
AXS Drivetrain Owners: If you are running RED or Force AXS, this cassette provides the "factory-intended" shifting experience with perfectly timed shift ramps.
Cadence-Focused Riders: The one-tooth jumps across the most used gears prevent the "searching for the right gear" feeling common with wider-range cassettes.
❌ Why This May NOT be for you
Standard HG Hub Users: This cassette will not fit on traditional Shimano/SRAM 11-speed freehubs; you must have an XDR-compatible wheelset.
Budget Builders: As a flagship product, the SRAM RED E1 is a significant investment. For better value with a small weight penalty, the SRAM Force XG-1270 uses the same tech at a lower price point.
Mechanical Drivetrains: While technically compatible with some setups, the tooth profiles are specifically optimized for the precise, high-torque movements of electronic AXS derailleurs.
BFC Pro Tip
To maximize the life of this high-end steel cassette, we strongly recommend pairing it with a new SRAM RED E1 Flattop Chain. Using an old chain on a brand-new X-DOME cassette can cause "micro-skipping" and significantly accelerate wear on the expensive machined teeth. Also, remember that the 10-36T ratio requires a "Max" or "36T" compatible rear derailleur; it will not work with older short-cage RED AXS models.
