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 | |