Honda CBR 125RW 2007 Owner's Manual page 180

Specifications
Power Transmission
primary reduction 3.350
gear ratio, 1st 3.455
2nd 1.941
3rd 1.450
4th 1.174
5th 1.041
6th 0.923
final reduction 2.800
standard drive (engine) sprocket: 15 teeth
sprocket sizes driven (rear wheel) sprocket: 42 teeth
final drive chain
DID428VI3-124LE
170 Technical Information