G3 - The disc brake scratching and making a sound -- solution tutorial (with English subtitles) 

The main principle is to adjust the position of the disc brake in the two screws against the inside, and debug the position of the two screws against the inside so that the adjustment does not make a strange noise as a good solution.
G3 - Adjusting Brake Tutorial (with English subtitles) • G3 - Adjusting Brake L...