[Al Skierkiewicz]

Without going into any detail over the technical discussion so far, all holds if you are trying to drive up an incline at 90 degrees. So your calculations are very likely correct. When running on a level surface the power needed to move a robot is reduced with friction being the greatest force preventing movement. The friction comes together as the sum of the drive train friction, (which is minimally affected by robot weight with the use of bearings to transfer the robot weight to wheel shafts) and the wheel to surface friction which is affected by robot weight and floor matierial. All of the forces are still present but change dominance depending on the attitude of the robot. The power required for movement is that which is needed to overcome the sum of the frictions plus a little extra to get the mass in motion. Someone explained it to me as to why a 20,000 lb aircraft can get off the ground with only a 10,000 lb. thrust engine. You are not trying to drive the plane straight up, just to get up enough speed to let lift take over and you are flying.
Remember that many robots were able to design lift mechanisms a few short years ago when the competition demanded it so there must be ways of designing a mechanism to lift 130 lb.
Good Luck All
P.S. This is just an explanation from an electrical guy.