Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Determining a proper pulley ratio for any given set-up is a wide-open question that has no answer that can be given as a useful generalization.

It mostly depends on the load being driven and the power available to drive it, but there are more variables than that involved as well, such as what speed is being sought and what speed is available to achieve it.

There are certainly more ratios available than just 1:1 or 2:1, and of course the ratios can go both ways, that of gearing UP or gearing DOWN, again depending on the issues listed in the second line above.

Experimentation is likely your best option to determine your best ratio!