[Chriszuma]

We had that problem last year with our massive 1.5" brecoflex 4-wheel drive. This year we switched to a six-wheel drive. With the center wheels mounted about a quarter inch lower than the front and rear pairs, most of the weight is on the center wheel, which allows for insane turning, and insane traction at the same time. In fact, we just got the chassis driving last week and we were having so much fun just spinning the thing in high gear circles, something that wouldn't have come close to working last year.

So yeah, it's probably a bit late to add another pair of drive wheels to your chassis, but for next year, definitely go 6-wheel. Last year we partially fixed the problem by using the beige diamond-shaped tread on the back wheels and the super grippy black tread on the front wheels.