Because I am a domestic manufacturer, I thought it was safe, purchased for my son 's school bicycle exchange. Cracks occurred on the side in half a year after replacing. Then the crack expanded. It did not last a year and a half, and there was no groove on the rear side. The first tire (made in BS) did not crack even when it took three years, and there was still a little groove. The school road is about the same distance and course. I am sorry just because I trusted it domestically. Next we ordered BS tires.