Phenomenon: Straight bead sag Diagnosis: Straight bead sag is caused by the bead cord fabric joint. The joint part is a local reinforcement of the carcass. When the tire is inflated, this area expands less air than the area without joints, causing the tire
The edges are partially sunken. In fact, not all straight bead depressions will affect the safe use of the tire. The carcass joint is the overlap of the carcass material (polyester cord) at the joint in order to obtain a strong joint between the two parts of the carcass. The part of the tire joint that causes the straight bar depression on the sidewall is a relatively strong part of the tire carcass and will not affect the safe use of the tire. Generally speaking, the dents caused by the carcass cords correspond to the positions on both sides of the tire. This is also a way to judge whether the normal dents are caused by the cord joint problem. In addition to the normal straight sidewall depressions, the depressions that occur under other conditions will cause the car owners to pay enough attention. Among them, it may be the tire failure caused by the tire bead cut, the tire bead impact damage or the rubber degradation.
Recommendation: Do not allow the tire to come into contact with hydrocarbons, solvents or certain acids. Once these substances contact the rubber part of the tire, it will cause chemical changes in the rubber in a short time, causing the tire to swell, soften or become sticky.