The 13-31 block could have been exceeded, but at the expense of the evenness of the gearing. For example, compare the wider ratio 13-34 block:
|
sprkts ideal |
13 |
16.532 |
21.024 |
26.736 |
34 |
|||||
|
sprkts integer |
13 |
17 |
21 |
27 |
34 |
|||||
|
delta squared |
0.0% |
21.9% |
0.1% |
7.0% |
0.0% |
error = |
0.54 |
to the one that I selected:
|
sprkts ideal |
13 |
16.15 |
20.07 |
24.95 |
31 |
|||||
|
sprkts integer |
13 |
16 |
20 |
25 |
31 |
|||||
|
delta squared |
0.0% |
2.4% |
0.6% |
0.3% |
0.0% |
error = |
0.18 |
The root-mean-square error is three times larger with the 13-34 combination, so it will give much less even gearing,