i dont know why some would move and some dont. i mark mine every time they are mounted. i use no lube, just water to seat the bead. the tire is a 11" tread width and 29" tall. i do leave off a brake with a mild 440. best 1/8th of 6.80. the move 1/16 to 1/8 every hit. i'd screew them, but the car is made to look like a street car and i dont want that look. i also run tubes for the time being , since i picked up a screew in one tire. i will also periodicaly deflate the rear tires as to allow the tube to find it's way back where it started.