chain roller diameter:

0.3120 in
0.4000 in
0.4690 in
0.6250 in
0.7500 in
10 mm
10.160 mm
12 mm
12.065 mm
15.875 mm
16 mm
19.050 mm
25.400 mm
27.940 mm
29.210 mm
6 mm
6.350 mm
8.509 mm
9 mm