Alcohol does not help!
After a non-alcohol induced think I have to say that what I posted earlier was Bo**ocks!
With the exception of the nominal friction of the gear - of course it would move forward - unless the conveyor was capable of infinitive speed which would of course set the gear on fire!
The prop is biting the air and the air is not conneted to the ground - so apart from spinning the wheels, nothing would change!
Coat is on - left the building!