co2 pump question

I've been carrying around a co2 pump and cartridge for months now and haven't needed to use them...which is a good thing. Anyhow, last night a guy I was riding with flatted. It was getting dark and looked like rain so I offered my co2 pump on the condition that I got to use it - since I've never used one before. The tube (presta) inflated like magic! It was great. But I noticed quite a bit of gas escaping from the pump/valve. Is that normal or did I not have it seated on the valve quite right? Also, the valve itself was frosted after inflating. Like I said, I hadn't done this before, and neither had he, and so I was just wondering if I did it completely right. The tire filled so I guess it was basically right. Just wondering if the other stuff is normal.

I haven't used such a pump but I am keen to know about user experience since I am thinking about getting one.

li10up do you have to carry the co2 cardtridge seperately or did you have it in the pump all those months. I am just curious if they leak air/pressure when seated in the pump (andnot use it). And second question, can you use the co2-cardtridge only once?

I put the cartridge upside-down inside the co2 pump so there is no chance of it puncturing accidentally. I also carry a spare in my seat bag. One 16oz cartridge will inflate one road bike tube to about 100 psi. I think it will fill a mtn bike tube with a little left over. Once punctured though they will leak so trying to save the leftover is futile...from what I was told when I bought the pump. He didn't say anything about the co2 leaking out when filling the tube though so I'm not sure if this is normal or not. And the freezing of the stem kind of freaked me out a bit. If I don't get an answer here I guess I'll have to go back to the shop to find out if I'm doing it right.

Can you give me the brand and model. Not that there is a big chance the sell it overhere, but still.....

I personaly was looking at the SKS Airchamp

The freeze is easy to explain by the laws of physics.

When pressure goes down, so does temperature. (The inverse is also true.)

So as the 16 oz of CO2 that are compressed in the tiny cart get to expand, the pressure in the cart goes down pretty fast. Hence the cold. When I use the carts, I never touch them with my fingers, I think it's cold enough that you could loose some skin there. (If you live in the North you know what I mean!!)

I haven't used them so often, but I never had a perfect fit on the valve, still inflated the tire all right. I'd recommend to everyone to have a pump though, because when your CO2 doesn't work for some reason, well... you're stuck.

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Originally Posted by Mimosa

Can you give me the brand and model. Not that there is a big chance the sell it overhere, but still.....

I personaly was looking at the SKS Airchamp

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That's the one I have!!! I've only used it once but it worked great! There are probably less bulky and lighter ones but this was very easy to use. There are some that just have a head and when you turn it it releases the gas. But I like this one because it has a trigger to it.

Word of caution. When you do go to use it make sure your hand isn't depressing the trigger while you are screwing it together. I let out some of the co2 by doing that...oops. Also, at first I couldn't get it to work. You have to make sure the top is fully screwed on or it won't puncture the cartridge. I think you'll like the pump if you decide to go with it.

Owh cool :cool:, then I probably will get one in the near future to give it a go.

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Originally Posted by Grog

The freeze is easy to explain by the laws of physics.

When pressure goes down, so does temperature. (The inverse is also true.)

So as the 16 oz of CO2 that are compressed in the tiny cart get to expand, the pressure in the cart goes down pretty fast. Hence the cold. When I use the carts, I never touch them with my fingers, I think it's cold enough that you could loose some skin there. (If you live in the North you know what I mean!!)

I haven't used them so often, but I never had a perfect fit on the valve, still inflated the tire all right. I'd recommend to everyone to have a pump though, because when your CO2 doesn't work for some reason, well... you're stuck.

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I understand why the freeze...just expected all the co2 to go inside the tube...didn't expect the valve to get all frosty. I do carry a mini pump as a backup. I heard it take about 200 strokes to fill a tube with a mini pump and even then you might not be able to get it up to 100 psi. Took about 3 seconds with the cartridge. I'm definitely sold on co2.

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Originally Posted by li10up

One 16oz cartridge will inflate one road bike tube to about 100 psi. I think it will fill a mtn bike tube with a little left over.

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I think you need the mega 25g cartridge for mt bike tubes. I think 16g gets you to 30-40 psi only (depending on size of tire) ... that might be fine, but if you want in the 60s you'd need more. 12g should take a roadish tube to 90 psi and 16g closer to 120 psi I think.

I love CO2 ... they work like magic! I carry a combo ... I can pump a little to shape my tube then blast it. It also is insurance for the 2+ flat ride ... or the stranger too far out to get my CO2.

I've left the old cartridge in the CO2 pump after using it, and still there was enough from time to time to put a little more in on other days if a tire was just a bit low. I think they're the best.

The one negative that I continue to hear about co2 pumps is that the cartridges are non-recyclable. I've been lucky that I've yet to have a flat while out riding, away from my handy-dandy floor pump, but when I do I'll probably give the mini-pump a try before I reach for the emergency co2 in my saddle bag. Gotta do what I can to keep from adding to those landfills!

I looked around a bit more and found one from PRO (a Shimano brand) a co2 pump which is combined with a handpump, click here for more

A friend has a flat last weekend and the pump we brought did not accomodate her type of valve. I pulled out my "never before used" CO2. It works on any valve. presto, tire inflated. I carry extra cartdriges in case one doesn't work. Pump is best but bulky to carry. I did find a nice small carbon composite pump but I don't love riding with so much stuff hooked up to my bike. Feels like I am driving a station wagon.:(

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Originally Posted by Kalidurga

The one negative that I continue to hear about co2 pumps is that the cartridges are non-recyclable.

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I've heard the opposite, that they are recyclable. But maybe it depends on your local recycling program?

I haven't had to use any this year....no flats on the road or off road....so knock on wood.

The folks at MEC used not to sell them because they could not find any company to recycle them, but sometime this summer they told me they would carry them in the near future because they had found a recycler. Not sure what has happened since (http://www.mec.ca).

Of course carrying a pump adds to the bulk, but it certainly reduces inconvenience and increases safety when you're on a low-traffic road, 50 km from home, with a second or third flat tire and no more CO2, or after you've helped someone on the road and then get your own flat. Murphy's law says that on a given day you will have as many flats as the number of spare tubes you have and patches you have + 1. Also applies to CO2.

CO2 cartridges can be recycled. Just take them to the same location that recycles scrap metal. Our everyday purchases have a lot more "scrap" material built into the packages than co2 cartridges. At least the ones I buy don't even come in packages - just individual cartridges at the LBS. And I've only used one in the last year.