Awafrican
Moderator
Never curbed that tire, however I have not contacted the Michelin as I'm not the original purchaser, I bought them with probably around 8k km on the at most >85% tread lifeManufacturing defects occur. And bulges can happen from turning/backing into the sides of curbs (or other incidents, for example), putting forces on them that they're not designed to see. Good news is you'll probably get a new tire, maybe even completely free (no tread-depth proration). Defects generally occur much more frequently on cheaper/lower-quality tires, though.