Bgott, I think his problem was that the R1 (the tire) was stationary while the rim spun inside of it. I would think with all the traction the R1 affords that the R4 would spin much easier providing the transfer of power from axle to rim to tire was there. I think the R4 offered enough resistance that it forced an under inflated R1 to loose the frictional resistance with the rim thereby causing the rim to rotate within a stationary tire. I think anyway. Rat...