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Sturmey-Archer XRF8[1]
  Number of gear teeth       Number of gear teeth           Number of gear teeth            
Gear Sun Gear 1 Pinion to Sun 1 Pinion to Ring 1 Ring gear 1 1=R to P, 2=Direct Stage 1 Gear Drive Ratio Stage 1 drive ratio as fraction Sun Gear  2 Pinion to Sun 2 Pinion to Ring 2 Ring gear 2 Path: 2=Direct, 3=P to R Stage 2 Gear Drive Ratio Stage 2 drive ratio as fraction Stages 1 and 2 Drive Ratio[2] Stages 1 and 2 drive ratio as fraction Sun Gear  3 Pinion to Sun 3 Pinion to Ring 3 Ring gear 3 Path: 1=P to S, 2=Direct  Stage 3 Gear Drive Ratio Stage 3 drive ratio as fraction Total Drive Ratio[3] Total drive ratio as fraction Ratio incre- ment
1 27 33[4] 33 96[5] 2 1.000 1           47 34[6] 34 73[7] 2 1.000 1           1.000 1           27 16[8] 16 60[9] 2 1.000 1           1.000 1            
2 27[10] 33 33 96 3 1.281 1    9/32   47 34 34 73 2 1.000 1           1.281 1    9/32   27 16 16 60 2 1.000 1           1.281 1    9/32   1.281
3 27 33 33 96 2 1.000 1           47 34 34 73 2 1.000 1           1.000 1           27[11] 16 16 60 3 1.450 1    9/20   1.450 1    9/20   1.132
4 27 33 33 96 2 1.000 1           47[12] 34 34 73 3 1.644 1   47/73   1.644 1   47/73   27 16 16 60 2 1.000 1           1.644 1   47/73   1.134
5 27 33 33 96 3 1.281 1    9/32   47 34 34 73 2 1.000 1           1.281 1    9/32   27 16 16 60 3 1.450 1    9/20   1.858 1  549/640  1.130
6 27 33 33 96 3 1.281 1    9/32   47 34 34 73 3 1.644 1   47/73   2.106 2   31/292  27 16 16 60 2 1.000 1           2.106 2   31/292  1.134
7 27 33 33 96 2 1.000 1           47 34 34 73 3 1.644 1   47/73   1.644 1   47/73   27 16 16 60 3 1.450 1    9/20   2.384 2   28/73   1.132
8 27 33 33 96 3 1.281 1    9/32   47 34 34 73 3 1.644 1   47/73   2.106 2   31/292  27 16 16 60 3 1.450 1    9/20   3.054 3   63/1168 1.281
[1]
John Allen:
Drive ratios were deduced from gear-ring sizes listed in technical information.
[2]
John Allen:
This is the gear ratio after the second stage, the product of its ratio and that of the first stage.
[3]
John Allen:
This is the final drive ratio, the product of the ratios of all three stages.
[4]
John Allen:
This number may not be exact, as the hub was not opened to count teeth. However, it does not affect the drive ratio.
[5]
John Allen:
Number is from parts list in Sturmey-Archer technical information
[6]
John Allen:
This number may not be exact, as the hub was not opened to count teeth. However, it does not affect the drive ratio.
[7]
John Allen:
Number is from parts list in Sturmey-Archer technical information.
[8]
John Allen:
This number may not be exact, as the hub was not opened to count teeth. However, it does not affect the drive ratio.
[9]
John Allen:
Number is from parts list in Sturmey-Archer technical information
[10]
John Allen:
Number was deduced from Sturmey-Archer technical information based on gear-ring tooth counts and final ratio in this row.
[11]
John Allen:
Number was deduced from Sturmey-Archer technical information based on gear-ring tooth counts and final ratio in this row.
[12]
John Allen:
Number was deduced from Sturmey-Archer technical information based on gear-ring tooth counts and final ratio in this row.