Sunday, November 19, 2023

Ultegra Rear Derailleur: R8000 (Mechanical) vs R8050 (Electronic)

Here is another component comparison! I love doing side by side comparisons as it is interesting to spot the differences and try to understand why they are designed differently.

This comparison is between two Ultegra derailleurs of the same 11 speed generation. R8000 is the mechanical 11 speed rear derailleur, while R8050 is the Di2 11 speed electronic rear derailleur.

For this generation of Ultegra components, they are designed so that the mechanical and Di2 versions look similar, with the same design language. Other than the functional and dimensional differences, the visuals will be kept similar.

R8050 Di2 rear derailleur was removed from the Dahon MuSP, when it was modified from Ultegra Di2 11 speed to Sora 1x9 speed.

R8000 on the left with visible cable adjust bolt. R8050 on the right with the servo motor.

View from the bottom. Link set design is different as the mechanical and electronic versions work differently.

The cage set is the same, as studied in this other post.

R8000 on the left is operated mechanically, with a steel cable pulling the link arm. R8050 on the right uses a servo motor to move the link set electronically.

Close up look at the cable adjust on the R8000, while R8050 on the right has a connection port for the Di2 wire.

Weight of mechanical R8000 rear derailleur is just 197 grams which is lightweight.

Di2 R8050 is heavier at 239 grams due to the servo motor. But it is still considered lightweight as well.


  1. Hey man, great content! It's really nice to find someone actually doing these deep dives in this day and age.

    I have a R8050 SS which I'm been thinking about converting to GS to better acommodate my 32t cassete. So from your analysis, I understand is possible to use the R8000 GS cage set, is that right?


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