Gear Inches
 


27 Inch (nominal) Wheel

Number of Chainring Teeth



38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53
Number of Cog Teeth 12 85.5 87.8 90.0 92.3 94.5 96.8 99.0 101.3 103.5 105.8 108.0 110.3 112.5 114.8 117.0 119.3
13 78.9 81.0 83.1 85.2 87.2 89.3 91.4 93.5 95.5 97.6 99.7 101.8 103.8 105.9 108.0 110.1
14 73.3 75.2 77.1 79.1 81.0 82.9 84.9 86.8 88.7 90.6 92.6 94.5 96.4 98.4 100.3 102.2
15 68.4 70.2 72.0 73.8 75.6 77.4 79.2 81.0 82.8 84.6 86.4 88.2 90.0 91.8 93.6 95.4
16 64.1 65.8 67.5 69.2 70.9 72.6 74.3 75.9 77.6 79.3 81.0 82.7 84.4 86.1 87.8 89.4
17 60.4 61.9 63.5 65.1 66.7 68.3 69.9 71.5 73.1 74.6 76.2 77.8 79.4 81.0 82.6 84.2
18 57.0 58.5 60.0 61.5 63.0 64.5 66.0 67.5 69.0 70.5 72.0 73.5 75.0 76.5 78.0 79.5
19 54.0 55.4 56.8 58.3 59.7 61.1 62.5 63.9 65.4 66.8 68.2 69.6 71.1 72.5 73.9 75.3
20 51.3 52.7 54.0 55.4 56.7 58.1 59.4 60.8 62.1 63.5 64.8 66.2 67.5 68.9 70.2 71.6
21 48.9 50.1 51.4 52.7 54.0 55.3 56.6 57.9 59.1 60.4 61.7 63.0 64.3 65.6 66.9 68.1
22 46.6 47.9 49.1 50.3 51.5 52.8 54.0 55.2 56.5 57.7 58.9 60.1 61.4 62.6 63.8 65.0