[CharleyB]

Recently had a flat on my -6A. The base of the valve stem was cut just after the stem exits from the tube itself. Apparently the cut was done by the wheel rim. The guilty part is the hole on the inside of the rim - actually half of the hole is on each half of the rim. I have no grommet on that hole - never have, and wonder if I missed something in the initial wheel/tire assembly years ago.

Is there supposed to be a rubber grommet in the hole that centers and protects the valve stem?

 

[Bavafa]

I am pretty sure there is no grommet, it seems your tire & tube has turned in relation to the rim thus cutting the valve stem. I need to keep the pressure in my nose tire up 35+ PSI (usually between 40-45) to prevent flats otherwise I get pinhole in the side wall side of the tube.