Short Cage Rear Derailleur

Short Cage Rear Derailleur

Ultegra RD-6870-SS

The Shimano RD-6870-SS is their short cage rear derailleur for the 6870 series.

It supports a max front difference of 16T, a low sprocket minimum of 23T, and a **low sprocket maximum **of 28T. The top sprocket maximum is 14T and the minimum is 11T. It has a total capacity of 33T.

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It also features Shimano's Crash Protection Mode - this prevents shifting after a crash to make sure the rear derailleur is damaged any further. To restore shifting functionality have a look at the FAQ: I had a small crash and my rear derailleur stopped working.

When paired with 6870 or newer components and the BT-DN110 battery, this derailleur supports synchronized shift.


  • Model code: RD-6870-SS
  • Series: Ultegra (6870)
  • Weight: 257g
  • Speeds: 11
  • SD50 ports: 1
  • Max front difference: 16T
  • Total capacity: 33T
  • Low sprocket max: 28T
  • Low sprocket min: 23T
  • Top sprocket min: 11T
  • Top sprocket max: 14T
  • Pulley teeth: 11
  • Mount: Conventional mount
  • RD type: Non-shadow RD
  • Clutch: No

Related components

View the Medium Cage Rear Derailleur (RD-6870-GS)


Medium Cage Rear Derailleur

View the Front Derailleur (FD-6870-F)


Front Derailleur

View the Dual Control Lever (ST-6870)


Dual Control Lever

View the Internal Battery (BT-DN110)


Internal Battery

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