This document provides an overview of the internal components and operation of a 3-speed Sturmey Archer hub gear system. It details the planetary gearing setup involving a sun gear, planet cage with 4 planets, gear ring, and hub. It explains how in 3rd gear, the clutch engages the planet axles to drive the gear ring and hub faster than the driver. In 2nd gear, the clutch disengages from the planets and drives the gear ring and hub at the same speed as the driver. In 1st gear, the clutch blocks the gear ring pawl to cause the planet cage to drive the hub slower than the driver via the gear ring.

1. Hub gears for dummies Sturmey Archer 3 Speed Hub Technological design Engineering Alexandre De Bie

2. What’s Inside Technological design Engineering Alexandre De Bie

3. Technological design Engineering Alexandre De Bie Driver and sprocket

4. Technological design Engineering Alexandre De Bie

5. Technological design Engineering Alexandre De Bie Planetary Gearing Hub

6. Hub (Wheel) Technological design Engineering Alexandre De Bie Hub Teeth

7. Planetary Gearing Technological design Engineering Alexandre De Bie Gear ring 4 planets Sun (Fix) Section

8. Axle and Sun gear Technological design Engineering Alexandre De Bie Sun gear Axle

9. Planet Cage with Planets Technological design Engineering Alexandre De Bie 4 Planet axles 4 Planets 2 Planet cage pawl Cage

10. Gear ring Technological design Engineering Alexandre De Bie Bottom View 4 Tabs 2 Pawls Gear ring teeth

11. Sprocket - Planetary gearing connection Technological design Engineering Alexandre De Bie Clutch Sprocket Planet axle

12. Planetery gearing – Hub Connection Technological design Engineering Alexandre De Bie Gear ring pawl Cage pawl Hub teeth

13. Technological design Engineering Alexandre De Bie Choosing the speed 3rd Speed Spring Force 2nd Speed 1st Speed

14. 3rd speed (High) Technological design Engineering Alexandre De Bie How it works Clutch rest against planet axle

15. Technological design Engineering Alexandre De Bie Driver drives the planet cage Planet cage drives the gear ring. 90° 120° Cage rotates 90° Gear ring 120° Cage rotates 3 times Gear ring rotates 4 times Hub drives as fast as gear ring Make 3 rotation with the driver to make 4 rotations with the wheel Gear ring connected to hub with pawl

16. 2ndSpeed (Normal) Technological design Engineering Alexandre De Bie Clutch rest against tabs from the gear ring Contact with cage lost

17. Technological design Engineering Alexandre De Bie Driver drives the gear ring Hub drives as fast as gear ring Make 1 rotation with the driver to rotate the hub 1 time Gear ring connected to hub with pawl

18. 1stSpeed (Low) Technological design Engineering Alexandre De Bie As in the 2nd speed no contact with the cage Clutch rest against tabs from the gear ring And blocks the gear ring pawls

19. Technological design Engineering Alexandre De Bie 2nd Speed pawl not blocked 1stSpeed clutch blocks pawl Gear ring is unable to grab in the hub teeth

20. Technological design Engineering Alexandre De Bie Driver drives the gear ring Gear ring drives the planet cage 120° 90° Gear ring 120° Cage rotates 90° Gear ring rotates 4 times Cage rotates 3 times Hub drives as fast planet cage Make 4 rotation with the driver to make 3 rotations with the wheel Planet Cage connected to hub with pawl

21. Technological design Engineering Alexandre De Bie