Not quite that simple - yes you generate a 600 "gram" force, but a wheeled robot on a horizontal surface that weighs 600 grams does not need that much force to move.
Also, that appears to be the stall torque - the torque generated when the motor is not turning. As the motor speeds up, the torque is reduced.
http://www.societyofrobots.com/mechanics_dynamics.shtmlThere is a link to a motor calculator there as well.