Index Rear Derailleurs and set Front Derailleur limits using E-Tube Project
Learn how to set up your di2 front derailleur electrical limits and index or micro-adjust your di2 rear derailleur using E-Tube Project 4.
Medium Cage Rear Derailleur
Ultegra RD-6870-GS
The Shimano RD-6870-GS is the medium cage rear derailleur for the 6870 series.
It supports a max front difference of 16T, a low sprocket minimum of 28T and a low sprocket maximum of 32T. The top sprocket maximum is 12T and the minimum is 11T. It has a total capacity of 37T and weighs only 11g more than the short cage derailleur - 268g.
Affiliate Links
Using the affiliate links to purchase anything earns the site a small commission, at no additional cost to you.
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.
Specifications
- Model code
- RD-6870-GS
- Series
- Ultegra 6870
- Weight
- 268g
- SD50 ports
- 1
- Clutch
- No
- RD Type
- Non-shadow RD
- Max front difference
- 16T
- Total capacity
- 37T
- Low sprocket max
- 32T
- Low sprocket min
- 28T
- Top sprocket min
- 11T
- Top sprocket max
- 12T
- Pulley teeth
- 11
Related components
View all components
Micro-adjust your 10-speed and 11-speed road bike Di2 rear derailleur
Micro-adjust your 10-speed and 11-speed road bike Di2 rear derailleur.
Installation Guide: 10-speed and 11-speed Di2 road Rear Derailleur
Bought a new Di2 rear derailleur and need some help installing it? Read how to install the RD-R8050 / RD-R9150 / RD-6870 / RD-9070 Di2 rear derailleurs.
Understanding Di2 derailleur specifications
What is a rear derailleur's total capacity, really? Why is there a top sprocket minimum? And what about front derailleurs? Chain line, total capacity, Top gear teeth? This page explains all of those, and more.