Originally Posted by
SkyDog75
The rim could be the source of your problems, but another possible source for holes in that area is force applied to the valve stem from a pump. Hand pumps can be prone to pulling the valve stem side-to-side if you're not careful and have been known to rip a valve stem out. I've had a floor pump with a really tight chuck that ripped out a valve stem when I tried to disconnect it. I've known of at least one person who puts a nut from a threaded presta valve on the inside of the rim so that any force on the valve stem pulls on the nut, not on the rubber tube. I suppose that might also possibly shield the tube from being pinched or punctured at the hole if that's your problem.
Yeah, I found that out to my misfortune on a trip last summer. Of course, it was a trip where I was stupid enough to not have a spare tube, assuming that a patch kit was sufficient, too. Luckily my riding partner had a tube that, while not the correct size, was similar enough to allow me to inflate my tire enough to ride the remaining 70km home, otherwise it would have been a VERY long walk.