What type of drive train is the most maneuverable?

[petek]

A very simple and highly-manuverable chassis is two-wheel drive with ball casters, as used recently by 56, 103 and many others.

Pros: It is very light weight and easy to implement, has fewer components than six-wheel drive and has very low scrub (frictional) losses when changing direction.

Cons: While it can push strongly in the forward direction, it has very low pushing ability off-axis or backward (due to weight transfer off the drive wheels). This system is best-suited to a flat and level field, as it has relatively poor drive dynamics when sideways on a sloped surface, such as a ramp, and would probably have a really tough time on steps!

Stay away from swivel casters, as they steer the robot in the direction they're turned towards - which often seems to be the wrong way!