Encoders on Drive Motors?

[cdizzle]

Originally Posted by DonRotolo

Get the mechanical guys to fix the problem. Otherwise you will be always reducing power to one side to compensate for the drivetrain problem. With the drive motors disconnected, you will find that one side of the drivetrain requires more effort to move than the other.

I pretty much am the mechanical guy, so what could be the root cause of the problem mechanically? The robot is just a chassis right now, so there isn't much on it except for the motors, wheels and the electronics board.