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My fancy digital Fox shock pump has a single-piece chuck which can leak when removed, and doesn't always depress Schrader valves, due to clearances. I had problems with a OneUp dropper which I couldn't top up
Two-part chucks first connect and seal then the valve is depressed, accommodating different clearances and avoiding leaks when disconnecting.
Can you suggest a two-part Schrader chuck which I could attach to my shock pump?
Google found a couple of possible solutions, but I'm not sure whether they'll do the trick.
SKS do a spare hose and two-part chuck for their USP and MSP shock pumps which would do if it's a Schrader fitting at the shock end.
Lezyne sell an 'ABS Shock Chuck' which looks like it might work.
Topeak do a couple of 'Presure-Rite' shock or valve adapters which look like two-part chucks with Schrader both ends.
Seems very odd that it would leak (not just the air in the hose). The chuck appears to be the same as almost every shock pump chuck I've ever used and to all visual appearances and design purposes should not do as yours does.
If yours is leaking as you suggest I'd go so far as to say you need to either warranty it or buy a replacement not an adapter as yours is faulty. Simply put, it shouldn't be possible to decompress your shock like that with a shock pump.
Yes that one. Otherwise, I think you're mistaken.
A single-part chuck, depending on the layout of the chuck and the recipient valve, will leak if the valve is open whilst the chuck is removed. If you're quick and there's enough volume of air in the shock, it may not affect the pressure much. The OneUp dropper has a small volume of air and a high pressure around 300psi. I was losing 100+psi when I disconnected.
Enduro's review deals with this:
The myth that the fork or shock will lose pressure as soon as you unscrew the pump head is still propagated on mountain-bike forums. In actual fact, not a single pump does that, as our test with the Quarq ShockWiz showed. It doesn’t matter how slowly you unscrew the pump or whether it has a manual check-valve – which incidentally exists purely because of this myth.
I have three shock pumps; the 'best' is the old, well-used two-part Fox which is great. With one of the others I can empty the dropper if I remove the pump slowly.
The two-part chucks avoid the problem - that's why they make them. And if I can stick a two-part on the end of my digital Fox I get the best of both worlds.