I've tried everything, swapping 3.0 to 2.6 to ZZ motors. I've tried changing gears. But my Bit runs like crap. It will run fine and then start to stutter and barely move. I thought at first the motor contacts weren't right, but they are. I've used ZZ motors with the large contact surface and the same thing happens. Then I thought maybe the gears weren't meshing correctly. It appeared as if the motor gear was too close to the idler gear. I shimmed it back a little and it spun more freely, but that did not solve the problem!

AS of now I am out of ideas...