I helped someone out today who had a problem with his replacement tube. The valve stem on his spare tube was short, and it barely stuck out of the rim. (I don't know why his spare tube had a 36mm valve stem [I have never seen shorter but it may have even been shorter than that] while the ones in the wheels were 60mm??) I wonder how long he was waiting on the side of the road. Unfortunately I didn't have my Lezyne hand pump which would have been able to grab on to the end of the valve stem, but we managed to pump his tube up enough to get moving again and didn't have to resort to patching the old one which would have taken a while.