Rear derailleurs
microSHIFT R9 Rear Derailleur 9 Speed Short Cage
RD-R42S-BK
Compatibility: reviewed
Known specifications can be used by the compatibility engine.
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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 1, 2026
- Compatibility review
- Reviewed Aug 1, 2026
Approved technical sources
- microSHIFT RD-R42S-BK official labeled model factsManufacturerSource checked Aug 1, 2026Evidence reviewed Aug 1, 2026
- microSHIFT road-rd-manual mount evidenceManufacturerSource checked Aug 1, 2026Evidence reviewed Aug 1, 2026
Technical data
Specifications
- Speeds
- 9-speed
- Supported speeds
- 9-speed
- Maximum cassette cog
- 28T
- Drivetrain family
- microSHIFT R9 / Shimano Road mechanical 9-speed
- Compatible drivetrain families
- microSHIFT R9 / Shimano Road mechanical 9-speed
- Frame mounting
- Conventional hanger
- Total capacity
- 33T