A quick basic chart outlining gear ratios. Very handy for finding sister ratios, such as 19/77 is the same as 20/81
| Engine | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| Sprocket | |||||||||||
| 70 | 7.000 | 6.364 | 5.833 | 5.385 | 5.000 | 4.667 | 4.375 | 4.118 | 3.889 | 3.684 | 3.500 |
| 71 | 7.100 | 6.455 | 5.917 | 5.462 | 5.071 | 4.733 | 4.438 | 4.176 | 3.944 | 3.737 | 3.550 |
| 72 | 7.200 | 6.545 | 6.000 | 5.538 | 5.143 | 4.800 | 4.500 | 4.235 | 4.000 | 3.789 | 3.600 |
| 73 | 7.300 | 6.636 | 6.083 | 5.615 | 5.214 | 4.867 | 4.563 | 4.294 | 4.056 | 3.842 | 3.650 |
| 74 | 7.400 | 6.727 | 6.167 | 5.692 | 5.286 | 4.933 | 4.625 | 4.353 | 4.111 | 3.895 | 3.700 |
| 75 | 7.500 | 6.818 | 6.250 | 5.769 | 5.357 | 5.000 | 4.688 | 4.412 | 4.167 | 3.947 | 3.750 |
| 76 | 7.600 | 6.909 | 6.333 | 5.846 | 5.429 | 5.067 | 4.750 | 4.471 | 4.222 | 4.000 | 3.800 |
| 77 | 7.700 | 7.000 | 6.417 | 5.923 | 5.500 | 5.133 | 4.813 | 4.529 | 4.278 | 4.053 | 3.850 |
| 78 | 7.800 | 7.091 | 6.500 | 6.000 | 5.571 | 5.200 | 4.875 | 4.588 | 4.333 | 4.105 | 3.900 |
| 79 | 7.900 | 7.182 | 6.583 | 6.077 | 5.643 | 5.267 | 4.938 | 4.647 | 4.389 | 4.158 | 3.950 |
| 80 | 8.000 | 7.273 | 6.667 | 6.154 | 5.714 | 5.333 | 5.000 | 4.706 | 4.444 | 4.211 | 4.000 |
| 81 | 8.100 | 7.364 | 6.750 | 6.231 | 5.786 | 5.400 | 5.063 | 4.765 | 4.500 | 4.263 | 4.050 |
| 82 | 8.200 | 7.455 | 6.833 | 6.308 | 5.857 | 5.467 | 5.125 | 4.824 | 4.556 | 4.316 | 4.100 |
| 83 | 8.300 | 7.545 | 6.917 | 6.385 | 5.929 | 5.533 | 5.188 | 4.882 | 4.611 | 4.368 | 4.150 |
| 84 | 8.400 | 7.636 | 7.000 | 6.462 | 6.000 | 5.600 | 5.250 | 4.941 | 4.667 | 4.421 | 4.200 |
| 85 | 8.500 | 7.727 | 7.083 | 6.538 | 6.071 | 5.667 | 5.313 | 5.000 | 4.722 | 4.474 | 4.250 |
| 86 | 8.600 | 7.818 | 7.167 | 6.615 | 6.143 | 5.733 | 5.375 | 5.059 | 4.778 | 4.526 | 4.300 |
| 87 | 8.700 | 7.909 | 7.250 | 6.692 | 6.214 | 5.800 | 5.438 | 5.118 | 4.833 | 4.579 | 4.350 |
| 88 | 8.800 | 8.000 | 7.333 | 6.769 | 6.286 | 5.867 | 5.500 | 5.176 | 4.889 | 4.632 | 4.400 |
| 89 | 8.900 | 8.091 | 7.417 | 6.846 | 6.357 | 5.933 | 5.563 | 5.235 | 4.944 | 4.684 | 4.450 |
| 90 | 9.000 | 8.182 | 7.500 | 6.923 | 6.429 | 6.000 | 5.625 | 5.294 | 5.000 | 4.737 | 4.500 |