Stupid questions about CO2 pump

Apologies for such stupid questions, but I have just bought a Zefal gas cartridge pump thing from Decathlon and the instructions are in pictures. Since I even have trouble deciphering the little pictures of men and women on toilet doors, I can be pretty confident I don't understand pictures!

Questions: It has a threaded end (female). Does this work with Presta valves?

How do you get the gas out of the little cylinder? It seems to be sealed.

If you use it on a tyre, is it one shot and throw away the metal cartridge, or can you return to re-use one that is part used?

This little gadget is intended for use by Mrs A, by the way. At present she relies on me to provide inflation manually, but I bought this thing for her as a "get you home" in case she is out without me. She sometimes joins a ride late if she is tinkering with her horse or something. Puncture mending lessons are scheduled for warmer weather.

Thanks for helpful answers.
 

Kbrook

Über Member
Yes it fits Presta, the seal is broken when you screw it on the adaptor. You then push it onto your presta valve having made sure the presta valve is open of course.
 
You can re-use an old cannister but you probably won't get much left in it after it's pumped your tyre up to a decent pressure.

Also, not that CO2 leaks much faster out of your tyre so pressure will drop fairly quickly. When I get home I let the CO2 out and re-pump it with traditional trackstand pump.
 
So, to be clear there is a canister and a inflator. You screw the canister into the inflatir and as you screw it in the inflator pierces the canister ready to use.

You then screw the inflator onto your tyre valve. The act of pushing them together is what releases the gas through the inflatir and into your tyre.
 

boydj

Guru
Location
Paisley
Be sure to wrap something round the cylinder when it is used, as it gets very cold very quickly and will 'burn' the skin. Cylinders are pretty cheap, so it's worth doing a test inflation just to be sure of how it works. A cylinder will be more or less empty after a single use.
 

dnrc

Über Member
Location
Norwich
So, to be clear there is a canister and a inflator. You screw the canister into the inflatir and as you screw it in the inflator pierces the canister ready to use.

You then screw the inflator onto your tyre valve. The act of pushing them together is what releases the gas through the inflatir and into your tyre.
as extra info, this isn't the case for all co2 pumps, i have a lezyne where you screw the cartridge all the way in, stick it on the valve and then unscrew the cartridge slightly to start inflating.
 
as extra info, this isn't the case for all co2 pumps, i have a lezyne where you screw the cartridge all the way in, stick it on the valve and then unscrew the cartridge slightly to start inflating.
I stand corrected
 

fossyant

Ride It Like You Stole It!
Location
South Manchester
I have the Zefal one from Decathlon.

When you need to use it.

1. Check the zefal's valve is closed on the nozzel.
2. Screw in cartridge all the way (i've once not screwed it in fully - it punctures the cannister).
3. Screw the unit onth the tube valve.
4. Undo the Zefal valve and hey presto the tube is inflated (in about 1 second).
5. Remove inflater

You can't re-use them - too much air comes out very fast.

Don't hold the cannister as it will freeze after the co2 has been released - just hold the zefal inflater. Also watch the valve stem as this will be cold too. You also have to be more careful in wet weather too as you get more freezing.
 
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