To solve an problem where conventionally, when assembling the wheel of a bicycle or a wheel chair, a belt of a rim groove width for preventing puncture is installed into the rim groove, belt terminals are overlapped on a valve hole of a rim, the valve holes provided on both ends of the belt are aligned, and fixed through a valve hardware of a tire tube, and therefore the technique is required for assembling, when the tire tube is depressurized or punctured, a valve stopping nut is loosened and the torsion is caused to a puncture prevention belt due to the inclination of the valve and breakage accident is easily caused.

The assembly of the wheel or detaching/attaching of the tire tube in repairing the puncture is facilitated with a metal fitting equipped with a belt presser-cum-rotation stopping flange on one end of a valve guide cylinder for passing through the valve hole of the overlapped part of both the ends of the belt for preventing the puncture used from the inside to the valve hole of the rim of the wheel of the bicycle or the wheel chair, and an auxiliary hardware for assembling the valve part is used as a valve guiding metal fitting characterized in that the torsion of the puncture prevention belt or the inclination of the valve in the puncture or the breakage of the valve hole of the belt in detaching/attaching is prevented.