You can easily improve the quality of the ball bearings by replacing them with the bearings Hybrid Ceramic ABEC5.
Brake alignment (part no. 4): Carbontex Shimano S#3
Bearing No. 5 specifications: R20
Note: A 0.9 mm Allen key is required to unscrew part no. 13.
Bearing No. 14:R19
Bearing No. 24: R5
Bearing No. 47: R18
Bearing No. 49: R7
Bearing No. 14: R19
Bearing No. 47: R18
Bearing No. 24: R5
Plastic bearing No. 71 can be replaced with a ball bearing R5