What Are Sidewall Separations / Bubbles?

Sidewall bubbles / separations appearing within the first three month could be from a issue in the manufacture process causing a bonding defect and should be returned to manufacture for confirmation if no evidence of impact / scuff or injury on wheel & tire are present.

During a sidewall separation the tire's internal components are damaged usually in service due to use while overloaded/underinflated, or by impact with potholes, curbs or other road hazards that pinch the tire between the rim and the road, or simply stretch the rubber beyond the elastic limit of the underlying cords and wires 

However even a single, significant impact with a deep pothole or sharp curb can cause a new tire and wheel to be damaged.

If the sidewall separation/bubble appears after three months of on-vehicle service, prolonged driving on overloaded/underinflated tires or a road hazard are the most likely causes. However it may take weeks or months after an impact for a separation/bubble to appear as the damaged or bruised area continues to weaken. Unfortunately the time differential between the impact that caused the initial damage and the delayed appearance of visible evidence often means that the driver has forgotten about the impact that damaged the tire in the first place.

The varieties of possible causes make it necessary to inspect the tire while mounted on the wheel (sometimes the wheel will show impact damage adjacent to the separation/bubble), as well as to dismount the tire and inspect the condition of its innerliner thoroughly. 

Any tires with bubbles or tread separations should be replaced immediately