[BrendanB]

If you are using the kit frame chassis you will notice that the hole for the center wheel is dropped by 1/8 of an inch. This is there so that you can put a 2 more wheels in your drivebase taking if from a 4wd to a 6wd setup and the chassis will rock between the front and back wheels and will greatly improve your turning ability. You can use the 2010 slick wheels or omni wheels on either the front or back to make your 4wd setup turn, but those wheels won't have a lot of traction if any.

You can either buy two more wheels, or use the 4 plactions in the back with 2 8in kit wheels in the front.