Robot veers left when driving backwards!

[ConKbot of Doom]

I would look at the drivetrain. Last year out bot when we would drive forwards would go to the right, and veer to the left when going back. It would make a 10 point turn just by going back and forward.

I thought it was the motors having more power in the forward direction than in the backward direction, but it turns out that the CIMs have the same power forward and backward, and it was the drivetrain that was doing it.

[Someone]

almost all motors have a powerful direction and a less powerful direction. for example, the van door motor has 30 Nm CCW and 34 Nm clockwise at at the same # of RPMS. are you motors on opposite sides going different directions?