Flatness rate is a data of tire, which refers to the percentage of tire cross-sectional height to its maximum cross-sectional width, which is simply the height-width ratio of tire. For example, a tire with a specification of 205/60 R 15 means that the maximum width of its cross section is 205 mm, the flatness rate is 60%, and the inner diameter is 15 inch. The flatness rate is 60%, that is, the tire section height is 205 * 60% = 123mm.
The tire section is composed of shoulder, sidewall and toe, and the sum of the three heights is the tire section height. After the tire is installed, the height from the rim to the outer cross section (crown) is slightly smaller than the tire cross section height.
The tire with high flattening rate has long sidewall, strong cushioning ability and relatively high comfort, but it has poor feeling on the road surface and weak lateral resistance when turning. On the other hand, tires with low flatness and large inner diameter are very sensitive to the road surface, have large lateral resistance when turning, and have strong vehicle maneuverability because of their short sidewall, wide tread and large contact area. After the vehicle is equipped with tires with large width, large inner diameter and low flattening rate, in addition to strong maneuverability, the visual effect of the appearance also gives people a very powerful feeling. (photo/text/photo:) Xpeng Motors P7 Model Y V Li ONE Weilai EC6 Model X @20 19