Ultegra 11-Speed Shifter/GRX 10-Speed Derailleur/11-Speed Cassette
| Shifter: | Ultegra 11-Speed | (ST-R8020) |
|---|---|---|
| Derailleur: | GRX 10-Speed | (RD-RX400) |
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| Speeds: | 11 | Use these numbers on a website like gear-calculator.com to find gearing that suits you and is compatible with this combo. |
| Max Tooth: | 36 | |
| Chain Wrap: | 41 | |
These combinations are not supported by the manufacturer. Use at your own risk.
Cassettes
| Cassette | Part Number | Support |
|---|---|---|
| SRAM 11-speed | sram-11-speed | Not Supported |
| Shimano 11-speed | shimano-11-speed | Not Supported |
Compatibility Analysis
Show Compatibility AnalysisEach click of the shifter will move the jockey by 3.61 mm on average. Manufacturers generally to target a cog pitch that is between 0.7% smaller to 6.9% larger than this number.
In practice, no groupset aligns the jockey wheel perfectly for every shift. Manufacturers generally allow the chain to make up to a 1.2° angle from the jockey wheel to the cog.
| Pull Ratio: | 1.45 |
|---|---|
| Cable Pull: | 2.50 mm |
| Minimum Cog Pitch: | 3.59 mm |
| Maximum Cog Pitch: | 3.86 mm |
| Maximum Chain Angle: | 1.2° |
SRAM 11-speed
Cog Pitch Versus Average Shift
The cog pitch of a SRAM 11-speed cassette is 3.72 mm, which is 2.9% larger than the average shift. This value is within the typical range for measured groupsets.
Worst Case Misalignment
This combination with a SRAM 11-speed cassette puts the chain at up to a 0.1° angle to the cog. This amounts to a sideways difference of 0.05 mm between the jockey wheel and the cog. This value is within the typical range for measured groupsets.
(Positions and angles are exaggerated for illustration. Numbers do not include the free play resulting from the cog being thinner than the rollers.)
Cog Positions vs Jockey Positions
Shimano 11-speed
Cog Pitch Versus Average Shift
The cog pitch of a Shimano 11-speed cassette is 3.75 mm, which is 3.7% larger than the average shift. This value is within the typical range for measured groupsets.
Worst Case Misalignment
This combination with a Shimano 11-speed cassette puts the chain at up to a 0.3° angle to the cog. This amounts to a sideways difference of 0.17 mm between the jockey wheel and the cog. This value is within the typical range for measured groupsets.
(Positions and angles are exaggerated for illustration. Numbers do not include the free play resulting from the cog being thinner than the rollers.)