Not really.
Your main thing to think about is what pinion gear you want to run on the motor. Now, that is a bit of a loaded response. It depends on what motor & what you are looking for. For example, Low end speed (quick acceleration), High top end, or in between. It also effects run times as well. Be careful as you can over/under gear. To high a gearing and you can overheat.... to low a gearing & you rob yourself some speed.
First pick your motor, then the pinion gear is a small (cheap) end to the means.
You can play around with this as well as long as you keep a general safe range.