Originally Posted by
Kat12
Can anyone explain to me as well how the Lezyne screw-on chuck works? I've only ever had lever-type bike pump heads (I've only ever had cheap pumps) and so I'm used to a pump where you flip the lever and it seals and that's how it keeps the air from coming back out. Then I find once I flip the lever to "open" so I can remove it, I have to do so quickly so I don't let all the air back out of the tire. How does this work with a screw-on chuck? Do I just have to unscrew it as quickly as possible before too much air escapes, or is there some way it seals?
I have one of the Lezyne pumps with the ABS-1 Pro on it. That uses one of their "Flip Chucks", but in a right angle configuration (which I find to be very convenient to use).
On the Schrader side, it appears to me that it makes a face seal at pretty much the same time that the valve is opened, i.e., I don't see any independent radial seal between the chuck and the valve.
I use mine mostly on Presta. On the few occasions that I have used it on Schrader valves, it has worked without any drama, and little or no leakage when removing; I didn't feel that I was fighting with it to avoid deflation while removing the chuck.
Full disclosure, I've only used it on a few Schrader valves. I don't know if there are any tolerance issues in the world of Schrader valves that would make some of them problematic compared to others when using this chuck.
Lezyne also makes a "Dual Valve" lever-action head, and equips some of their pumps with that. I tried one briefly, and decided that I preferred the ABS-1 Pro.