Frequent blow outs in the same location I keep getting blow outs in my front tube and always in the same location: right next to the valve stem. The blow outs look like:



On this same tube, there is wear on exactly the other side of the valve stem.  I have checked the tire and the wheel and there doesn't appear to be anything sharp enough there.

What can cause this? I suspect it's something that I'm doing. I'm tired of buying new tubes, as I hear these flats cannot be patched. If it matters, it's a presta valve and I usually inflate to 110 psi, the maximum.
Check inside the rim at the point where the punctures occur. 

Is the rim tape intact? 

Does a spoke push through when weight is placed on the bike? One of my friends had a problem like this, and it turned out that when he sat on the bike his weight caused the end of a spoke to push through the rim and puncture his tyre.