I've got duro hyper sonic tires on my bike, and the tubes keep flatting. Both front and back. I pulled both the tires off and checked the insides, and i can't seem to find any thing that would be puncturing the tube. I can't figure out what's going on with it. Are they just bad tires, any ideas?

When you pull the tubes, where are the puncture holes? Same place each time? On the tread side of the inner tube or the rim side?

One hole or two evenly spaced?