needed a valve extender for my spare tube, so wasn't looking to spend much just asked LBS what they had in their parts bin. the extender they gave me i've come to find out is is the type which is for non-removable valve cores. i do not know what brand it is. looked all over the internet and can't quite find exactly what it is.

my question is - when installed, the extender's integrated valve does not have a lock nut which screws down into a locked position like you would after filling your tires with air. it's just "open". if you press on it, the tire deflates, but it is basically as if you just left your presta valve lock nut unscrewed. there's no way to tighten this thing down.

will this "work"? can i ride along with a presta valve in the open position and not lose air? am i missing something about how this valve extender should be able to screw down into a locked position? i've tried everything and can't figure this thing out. read all the articles i can find including the old 2012 ST article about extenders. it appears this is the way the zipp ones work, they don't appear to have any presta nut on the end and appear to just rely on the "open" valve at the base of the extender....but before putting this thing in my spares kit and expecting it to work someday when im 50 miles from home, if someone can tell me this is all OK, that'd make me feel much better!

thanks.