Originally Posted by zonatandem
grab an old inner tube and cut about a 1 square inch patch out of it. Cut a small hole dead center of that patch and slip it over the valve stem before putting valve stem through the hole in rim. That little extra padding wil prevent tube from get pinched/cut.
Exactly right. I was having this problem with my IRO wheels (they flatted on the way home from staten island, and I wasn't even riding.) This fixed 'em right up.