[Answer42]

Any reason you're choosing not to power the outside omni wheels? Unless you have the 4 middle wheels on a drop center you're reducing the percentage of the robots weight on the driven wheels by 1/2. This would effectively reduce your pushing power by half, given that your low gear would likely be traction limited with 100% of driving weight on wheels anyways. That wouldn't be the worst thing in the world, but given that you opted to have shifters on the robot, I would assume pushing force was a desired quality for your robot. I also ask because it seems like you have room to easily add another 9mm belt on those double wide pulleys to drive the outside omni wheels.