Originally Posted by
Eplumer40
Wheels are Alex AT450, inner width 13mm.
Kind of narrow for a hybrid (I guess the bike is old). 25mm is kind of narrow for a hybrid too. You might be able to put 28mm on those rims (25mm is the largest recommended).
You might be better off with a wider tire, given your weight, but we still don't know enough about what's causing your flats.
Originally Posted by
Eplumer40
Does tightening down the presta screw have a significant impact on the tires?
You said the holes are on the tire side. The valve is not on the tire side. The nut has nothing to do with your issue.
Holes at the valve are fairly common and the nut (which isn't necessary) can be a part of holes near at the valve.
When you put the pump onto the valve, push the tire tread at the valve to make the valve stick out.