我国是一个自行车王国，废旧的自行车外股到处可见，只要留心收集，仔细检查，洗刷干净，按需要加工后，即可使用。它比竹圈、塑料圈有弹性、耐磨、耐摔，比铁圈安全。它不仅和其它圈一样可以钻。滚、跳，运用于体育活动之中，而且还可以踩、挤压、变形，用于力量性锻炼及技巧 China is a bicycle kingdom, discarded bicycles outside stocks can be seen everywhere, as long as careful collection, scrutiny, clean, according to the needs of processing, you can use. It is more flexible than bamboo lap and plastic lap. Not only can it be drilled like any other ring. Rolling, jumping, used in sports activities, but also can step, squeeze, deformation, for strength training and skills