Does the weight of the bagged ROBOT have to be less than 120 lbs? Could you put 200lbs of items in the bag and remove said items before inspection?
R15 All ROBOT elements (including items intended for use during the competition in alternative configurations of the ROBOT), with the exception of the WITHHOLDING ALLOWANCE per R18, BUMPERS, and COTS items, must be bagged and sealed, by 11:59PM local time on Stop Build Day, February 23, 2016
Since you must put all custom parts in the bag, including spares and items for different configurations of the robot, you are definitely allowed more than 120 lbs.