Tires look fantastic buddy... took me awhile to get caught up entirely on your thread, I was absent the last couple weeks of October.
Anyways, considering your motor options... I checked the motor output of the 4206, pulled the wheel off to get an accurate shaft rpm of 87 & my gizmo has a wheel adapter too, measuring surface wheel rpm 347. The 4206 has a 4 7/8" tire & the model moves along nearly at walking pace (I have a 36" inseam, I take big steps).
