Bald spots on your tires can be caused by a number of things, but one of the most common causes is improper inflation. When your tires are underinflated, the weight of the vehicle is not evenly distributed across the tread. This causes the tread to wear away faster on the edges, eventually leading to an inner bald spot.
If you notice a bald spot on your tire, it's important to take care of it right away. Continuing to drive on a bald tire is dangerous and can lead to a blowout. To avoid bald spots, make sure your tires are properly inflated and check their pressure regularly.