Adjust the rear derailleur (rear gear shift) to 0.1mm! (Road bike/Cross bike)

00:40　1. Role of rear derailleur
01:30 2. Things to check before adjusting the gear shift
02:40 3. Adjustment bolt name
03:15　4. Top side adjustment
08:03　5. Low side adjustment
11:50　6. B tension bolt adjustment
15:20　7. Shift wire tension adjustment
20:40　8. Notes on irregular combinations