Due to improper operation of the synchronous belt flex include improper storage, improper packing and synchronous belt before and after the installation of improper operation. When the synchronous belt with low tension runs, it may have been jump, until it reaches an acceptable tension. This phenomenon is called automatic tension. On the edge of the synchronous belt slack or the tooth of the synchronous belt into the driven pulley groove, automatic tensioning can be seen most clearly. When synchronous belt automatic tensioning, the tooth synchronous belt will jump out of the pulley groove, until the tension force of synchronous belt tension side to strengthen the tooth of the synchronous belt again into the pulley groove. When synchronous belt was forced to return pulley groove, synchronous belt and pulley often leads to severe instantaneous contact point between the bending, it will cause the damage of the synchronous belt core. This part of the core damage called buckling. If cannot make the tooth of the synchronous belt tension side tension into the pulley groove, will produce a jumpy tooth synchronous belt, also can produce buckling of the tooth synchronous belt failure or damage. When the synchronous belt into the small diameter of pulley, can also lead to synchronous belt core damage or bending failure. Pulley and the idler is lower than the specified value, pulley exists between synchronous belt and pulley, synchronous belt in your hands even bend into smaller acute Angle, this will lead to synchronous belt bending and failure. Foreign body into the drive system can also lead to bend synchronous belt. They will be in the acute Angle formed between synchronous belt and pulley, lead to the synchronous belt core bent on this point. Use tools to pry the timing belt pulley will damage the timing belt. When synchronous belt during the installation process by foreign body into the improper use or tool damage, synchronous belt will not immediately fails, but overall life will shorten of synchronous belt.