Is it legal to use VEX gears instead of traditional tires? They grip better on the foam, are lighter, and are easier to power. The only issue would be that it could be interpreted as damage to the field by some people. The gears’ teeth do push into the foam, but it appears that the foam pops back up after a few minutes.
This is one of those questions that we can’t give a blanket answer to without seeing the exact results. Thus an exact ruling will be left up to the determination of the event inspectors and referees.
If the gears are doing nothing but creating temporary depressions in the foam, they would be considered legal. However if the gears are “chewing” or taking chunks out of the foam, they would not be legal. You should be able to test this in advance of your events and make an appropriate determination.