SHIMANO GRX RD-RX400 Bicycle Derailleurs

The Shimano GRX RD-RX400 is a 10-speed rear derailleur designed for gravel and mixed-surface riding, featuring Shimano's Shadow RD+ clutch system to improve chain retention and drivetrain stability on rough terrain.

Best for

• Gravel bike riders using a Shimano 10-speed drivetrain.
• Cyclists riding mixed terrain, including pavement, gravel, and dirt roads.
• Adventure and bikepacking riders seeking improved chain security.
• Riders upgrading to a clutch-equipped rear derailleur for rough conditions.

Not ideal for

• 11-speed or 12-speed Shimano drivetrains.
• SRAM or Campagnolo shifting systems.
• Mountain bike drivetrains requiring MTB-specific derailleur compatibility.
• Users with incompatible Shimano road shifters.

What this product does

The RD-RX400 controls rear gear changes while using Shimano's Shadow RD+ clutch mechanism to reduce chain movement over rough terrain. This helps minimize chain slap, improve drivetrain stability, and reduce the likelihood of dropped chains during gravel and off-road riding.

Compatibility

• Compatible only with Shimano 10-speed drivetrains.
• Compatible only with the following Shimano shifters:
  • ST-RX400
  • ST-4700
  • ST-4720
  • ST-4725
  • ST-RS405
  • SL-4700
• Designed for Shimano GRX 10-speed gravel systems.
• Compatible with Shimano Shadow RD+ drivetrain technology.
• Not compatible with Shimano 11-speed or 12-speed shifters.
• Not compatible with SRAM or Campagnolo shifting systems.

Benefits

• Shadow RD+ clutch reduces chain slap on rough terrain.
• Helps prevent dropped chains during gravel riding.
• Provides more stable and controlled shifting over mixed surfaces.
• Clutch can be turned on or off depending on riding conditions.
• Designed specifically for gravel and adventure riding applications.
• Low-profile Shadow design helps reduce exposure to impacts.
• Delivers smooth and reliable shifting performance.

Technical Specs

• Product Type: Rear derailleur.
• Model: Shimano GRX RD-RX400.
• Series: GRX.
• Speed Compatibility: 10-speed.
• Cage Length: Long Cage.
• Color: Black.
• Technology: Shimano Shadow RD+.
• Clutch System: Integrated chain stabilizer.
• Clutch Adjustment: On/Off switch.
• Intended Use:
  • Gravel riding
  • Adventure riding
  • Mixed-surface cycling

Important

This derailleur is only compatible with Shimano 10-speed shifters that use the GRX RX400 / Tiagra 4700 cable pull ratio. It will not function correctly with Shimano 11-speed or 12-speed road shifters.