An important fact about your robot is the speed of the drivetrain. Having said that, how do I calculate the speed of the drivetrain? Fortunately there is an easy to use calculator called the JVN Calculator. You can find this at JVN Mechanical Design Calculator
You need either Excel or an open source spreadsheet program such as OpenOffice.
To use: Open the calculator and select the worksheet for the type of mechanism you want to calculate. Copy the appropriate motor data from the motor worksheet. Modify the purplish colored cells with the appropriate data for your robot or what you think you would want on your robot. Try 1 motor, or a larger wheel circumference, or a lower wheel coefficient to see the effects on the robot speed and current draw.
Older versions of the calculator are located at:
The older versions have slightly different information, and in some cases, have more information.
Can you calculate the speed of the 2013 KOP Drivetrain? Information on that is found here: 2013 KOP Drivetrain