JVN's Calculator (help)

[T^2]

Originally Posted by Kernaghan

It totally depends on how precise you wan't to be, but treating a sprocket ratio as a gear ratio may be different due to gear reduces efficiency. Aluminum sprockets I believe have an efficiency of about 90 - 92 % if your using two sprockets. So if you feel like calculating things yourself !

*snip*

This is simple, but may also be simplistic. Sprockets generally reduce efficiency, but so do a host of other factors, such as motor effectiveness at different loads, air drag, rolling resistance, and more, none of which are constant. We found that our overall efficiency this year was above 90% in low gear, and less than 80% in high gear. Unfortunately, there is no substitute for testing.