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Shimano GRX RD-RX820 12sp Rear Derailleur Parts - Rear Derailleurs - Gravel

GRX RD-RX820 12sp Rear Derailleur


The RD-RX820 is compatible with 11-34T and 11-36T 12-speed cassettes, providing a wide gear range so you can spin a comfortable cadence no matter the terrain type. The SHIMANO GRX 12-speed rear derailleur also features an integrated chain stabilizer that delivers quieter shifting and more secure chain management during rough rides. And the chain tensioner has an ON/OFF switch for outings on smooth surfaces.


  • Silent and secure rear shifting on rough terrain
  • Adjustable chain stabilizer prevents chain slap and drops
  • Smooth and reliable shifting on mixed surfaces
  • ON/OFF stabilizer switch matches terrain
  • Maximum front chainring difference: 17T
  • Top sprocket: Max. 11T/Min. 11T
  • Low sprocket: Max. 36T/Min. 34T
  • Total capacity: 42T

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