一辆跃进NJ1b61新车,行驶1.2万km便出现了两前轮轮胎异常磨损现象。驾驶员曾多次检查、调整前束值,并进行了轮胎换位作业,但仍未能解决问题。检查发现,两前轮轮胎均由胎冠外侧向里呈锯齿状磨损。根据经验判断,是由前束值过大引起。测量前束值为2.5mm,在设计标准1.5～3mm范围内;在侧滑试验台上测出其侧 A jumped NJ1b61 new car, driving 12000 km appeared two front tires abnormal wear phenomenon. The driver repeatedly checked, adjusted the toe-in value and performed the tire change operation, but still failed to solve the problem. Inspection revealed that the two front tires were jagged from the outside of the crown indented. Judging from experience, it is caused by an excessive toe-in value. Before measuring the beam value of 2.5mm, in the design standard 1.5 ~ 3mm range; measured in the side slip test bench its side