OK...here is how I see it at the moment.
Adding weight by loading the front tires probably will not cause a tractor to tip more easily.
In the case of a potential back flip, the added weight will be 100% beneficial.
In the case of a side slope, that tilts 90 degrees perpendicular to the frame of the tractor, the extra weight of the front tires, wheels and axle probably does not help until the axle bumps the stop on the down hill side.
At any point between directly backwards and 90 degrees perpendicular to the frame, the added weight of the front tires, wheels and axle will have some beneficial effect, which will lessen the more the slope angle approaches a line drawn between the operator’s shoulders.
The weight of the tires, wheels and axles on the front will do nothing to prevent a hand-stand wheelie…
Please let me get my head protector thingee done before we put my tractor on the 45 degree slope with Bob S in the driver's seat... /forums/images/graemlins/grin.gif