Small buldges can be simply the seam where the tire was put together and often are not a problem.

Large bubbles like a baseball size are caused by the internal cords breaking down. Often times this can be caused by a flat. If something like a nail punctures the tire especially on the crown it can allow water in, causing the steel belts to rust and snap. Hence a bubble forms.

Toyo's are ok. Les Schwab sucks. If you want the best warranty go to Big O. However the tires do cost a little more as they cannot compete with the bigger companies such as Les which buy in bulk and then store the tires in a warehouse for later distribution.

Worked at Big O for 7 years after I got out of high school. Started on tires then became a mechanic. Les is a rip, especially on the front end brake jobs where they automatically replace the calibers as a "maintenance issue."

This is BS if the pads wore evenly and the caliber piston moves in and out fine the calibers are good.

I hate les Schwab. If you are having any mechanical work done and are in the Monroe area go to Able Auto. They are very honest in my opinion.