by ober » Thu Jun 04, 2015 6:01 pm
rotating torque normally calculate in kg-cm, or Nm, or other unit. Let's take kg-cm, say a motor with the torque of 12kg-cm, this means the motor is able to turn 12kg if the load is 1cm away from the center shaft. If your wheel is 10cm, so it can only drive 12kg/10 = 1.2kg only. That is on book.
The actual case, there is a lot of friction which will reduce the total torque.