tire-screw

from The Century Dictionary.

• noun A tire-bolt; a conical-headed screw countersunk in the metal of a tire and passing radially through the felly, and held up by a nut on the inside over a curved washer-plate. It is intended to hold the tire in place sidewise and lengthwise, when the wheel is so light that a powerful shrinkage of the tire on the rim causes the wheel to go out of shape.