Motor selection

Everything depends on what you have at the other end of Timing belt.

Please give us more information on what the hell you want to do with your servo motor. I always select both belt and motor to be larger than I will ever need, that way they last a long, long time........

But a larger motor takes more power in both starting and stopping, it may not fit where you want it to go.....there are SO many variables that you need to set in cement before progressing further!