Jenson USANew · Checked Sep 20, 2026, 3:23 AM
$64.99In stockVisit store
Rear derailleurs
SRAM SRAM GX-T21 Rear Derailleur
10-speed · Long cage · Black
Compatibility: reviewed
Known specifications can be used by the compatibility engine.
Retailer offers
Where to Buy
Compare verified retailer affiliate links or search Amazon. We may earn a commission from qualifying purchases. Please confirm the exact variant before purchasing.
AmazonExact Match Verified
Catalog trust
Evidence and freshness
Technical-source dates and retailer offer checks are separate. A retailer check does not validate compatibility.
Report a correction- Technical review
- Aug 13, 2026
- Compatibility review
- Reviewed Aug 13, 2026
Approved technical sources
- SRAM MTB component compatibility mapManufacturerSource checked Jul 29, 2026Evidence reviewed Aug 13, 2026
- SRAM RD-GX-T21-A1 product pageManufacturerSource checked Jul 31, 2026Evidence reviewed Aug 13, 2026
Technical data
Specifications
- Speeds
- 10-speed
- Supported speeds
- 10-speed
- Maximum cassette cog
- 36T
- Supported front chainrings
- 1, 2, 3
- Drivetrain family
- SRAM Exact Actuation MTB Mechanical 10-speed
- Compatible chain families
- SRAM 10 Speed Powerchain
- Shift actuation
- Mechanical
- Frame mounting
- Conventional hanger