TYPE (STD/DX) GEAR RATIO 
Short Axel Distance (15.3mm): 
A type (M0.4) 60T/16T=3.75 
B type (M0.4) 62T/14T=4.43 
C type (M0.4) 64T/12T=5.33 
D type (M0.4) 66T/10T=6.60 
Long Axel Distance (35.1mm):
 
E type (M0.5) 124T/16T=7.75 
F type (M0.5) 126T/14T=9.00 
G type (M0.5) 128T/12T=10.66 
H type (M0.5) 130T/10T=13.00