[thefro526]

From my many experimentations I have found that gears are more reliable in high tourqe situations and some drivetrains. Whereas chain is good in tight areas so you can mount the motor else where and transmit power over a distance. Also I like to use 6 wheel drives alot and usually I have ATLEAST one wheel powered directly from the motor(through gears or direct drive) and then drive the remaining wheels with chain from that shaft and the hope is that if the chain breaks then the robot can still move a little. When you need to use chain in a high stress application it is better to use 2+ chains.