My rear tire was keep going flat while riding, so I felt around the tire for any punctures or abnormal ‘signs’ that may be causing the problem. One area felt too thick, and at first, I thought I just overinflated it and somehow the air got trapped. Later, I ended up pushing my bike into the rocks, and when the tire tread came off, I saw that the inner tube had literally folded up into a ‘Z’ shape inside the tire. How did this happen? I have never seen anything like this before.
Most likely incorrect tube and tire combo. Check your tube range if it matches the size of your tire. Could also be that you seated the tire incorrectly.
This can happen if your tire is underinflated and you use your rear brake a lot. When you brake, the tire drags and moves a little bit around the rim. Since the tube is anchored at the valve stem, it stretches on one side and bunches up on the other.