Frankly it doesn’t matter. I’m frustrated with Lezzzzz-steal my valve core every single time! What compounds the argh-factor is that Lezyne pumps are head and shoulders above the rest in every other way. Build quality is 10/10, the compression is superior to any other pump I’ve tried, and they’re pretty to look at too. Park actually made a tool to deal with it (of course it isn’t aimed at Lezyne but the timing is conspicuous, no?). Great tool regardless, btw.
This little dilemma actually brings to light a really crucial detail about presta tubes – the valve core. Wee little threads, with not much engagement; the valve core is a really delicate and integral part of a bike. Next time you’re putting air in your tires, lace up the kid gloves and be gentle. And be absolutely sure the top of the valve core gets seated properly as you screw it back in. That can be a recipe for a slow leak, and in the case of a tubular, an expensive mistake.
I would never attempt to affront the pride and self respect of any roadie, but every time a bike comes in with the little plastic caps on top of the valves, said valves are in pristine condition.
Ridiculous though, those things are at least half a gram each, right?