# Co2 Cartridge 12 gm versus 16 gm PSI max



## Red Dog (Dec 3, 2008)

*Co2 Cartridge 12 gm versus 16 gm PSI max - What is your experience?*

I'm hearing that a 12 gram cartridge will reach only about 85-90 psi and that a 16 gram will get up to about 100-105 psi.

Does anyone know what the 'facts' are? Or just comment on your experience.


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## lamazion (Sep 11, 2004)

Well, the package on the 16 gram states 130 psi for a 23c tire. I went with the 12 gram because they were less than $1 each at Dick's sporting goods (the 16 gram were $7.99 for two).


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## CleavesF (Dec 31, 2007)

My experience is that pumps are awesome.


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## Red Dog (Dec 3, 2008)

lamazion said:


> Well, the package on the 16 gram states 130 psi for a 23c tire. I went with the 12 gram because they were less than $1 each at Dick's sporting goods (the 16 gram were $7.99 for two).


Yep,...I just bought a Co2 system ( I also carry a pump) and expected the cartridge pricing to be about where the 12 grams were,...but have just found out that 'threaded 16 grams are expensive). Trying to find out if the 12 gram carts gets up around 105 psi. Did your 12 gram packaging state what psi was achievable? 

Thanks!


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## pr0230 (Jun 4, 2004)

*discount*



Red Dog said:


> Yep,...I just bought a Co2 system ( I also carry a pump) and expected the cartridge pricing to be about where the 12 grams were,...but have just found out that 'threaded 16 grams are expensive). Trying to find out if the 12 gram carts gets up around 105 psi. Did your 12 gram packaging state what psi was achievable?
> 
> Thanks!


http://www.gas-depot.com/index.php?main_page=index&cPath=2&zenid=173b59014ed0cbd5ea945d918b709e99

30 for 50 bucks ( including shipping ) - 1.70 each


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## lamazion (Sep 11, 2004)

Red Dog said:


> Yep,...I just bought a Co2 system ( I also carry a pump) and expected the cartridge pricing to be about where the 12 grams were,...but have just found out that 'threaded 16 grams are expensive). Trying to find out if the 12 gram carts gets up around 105 psi. Did your 12 gram packaging state what psi was achievable?
> 
> Thanks!



The 12 gram were for bb guns, so no they didn't state PSI. If no chimes in with an answer, I'll give one a try and let you know.


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## nOOky (Mar 20, 2009)

In my experience a 16 gram is too much for a 23mm road tire. I go with 12 gram threadless ones and an Ultraflate. I have had problems screwing threaded ones on enough to puncture the cartridge (Bontrager). The Crossman ones are 15 for under $8 at Walmart.
I think I checked a tire after I used a 16 gram one and it was 128 psi, I'd rather use all of a 12 gram and hit 90 psi than try to modulate a 16 gram to hit around 110 psi. YMMV


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## nOOky (Mar 20, 2009)

lamazion said:


> The 12 gram were for bb guns, so no they didn't state PSI. If no chimes in with an answer, I'll give one a try and let you know.


I've tried various brands, but a 12 gram is a 12 gram. I believe they are all made at the same one or two places and packaged differently.


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## Mr. Versatile (Nov 24, 2005)

I always carry the 16s. It leaves a little left over for refills, if needed.


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## Red Dog (Dec 3, 2008)

pr0230 said:


> http://www.gas-depot.com/index.php?main_page=index&cPath=2&zenid=173b59014ed0cbd5ea945d918b709e99
> 
> 30 for 50 bucks ( including shipping ) - 1.70 each


Yes I saw that. But, the 12's can be had (non-threaded) for .50-.75 cents in bulk on ebay. + shipping. Dang....I could own three 12 gram carts for one 16 gram! Same at Wal-Mart.


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## Red Dog (Dec 3, 2008)

Mr. Versatile said:


> I always carry the 16s. It leaves a little left over for refills, if needed.


Not sure what you mean about 'refills'...? Once your gas is low....what purpose would a low cart be good for?


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## Dinosaur (Jan 29, 2004)

I pack 12g and a mini. A 12g cost around $.56 per cartridge at Kmart or WalMart (come in packs of 25). I seat the tube with a mini (or frame pump, depending on which bike I am riding). Inflate to a guessable 40psi and finish off with c02. I would not depend just on co2 as I have run out on rare occasions my cell phone will not get out at some of my locations. Works for me.

I used to pack an Torelli Aria mini, which is about as small as they get. Problem is if you need to use the thing to inflate your tire you will probably be out there until the cows come home...


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## estone2 (Sep 25, 2005)

Red Dog said:


> Not sure what you mean about 'refills'...? Once your gas is low....what purpose would a low cart be good for?


If you're retarded (like me) and screw up, there's some room for error.


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## danl1 (Jul 23, 2005)

Red Dog said:


> I'm hearing that a 12 gram cartridge will reach only about 85-90 psi and that a 16 gram will get up to about 100-105 psi.
> 
> Does anyone know what the 'facts' are? Or just comment on your experience.


That's about in line with my experience with 12g cartridges and 23mm tires. I would expect 16g's to be higher and have heard it reported as 120ish, but don't have personal experience.


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## pmf (Feb 23, 2004)

I laways figered the 16 gram cartridges were for mountain bikes. I'd assume they'd blow up a road tube. The 12 gram ones inflate enough to get you home, and they're cheap at sporting goods stores that sell air gun accessories.


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## Mel Erickson (Feb 3, 2004)

*Straight from the horses mouth*



Red Dog said:


> I'm hearing that a 12 gram cartridge will reach only about 85-90 psi and that a 16 gram will get up to about 100-105 psi.
> 
> Does anyone know what the 'facts' are? Or just comment on your experience.


Innovations publishes this inflation chart. It's rule of thumb because most of us use 700c tires rather than 27" (wtf?) I've found that a 12g cartridge inflates my 700x23c tires to about 90psi and it inflates my 26"x2.1 mountain bike tires to 30psi. That's just fine for my mountain bike because I run tubeless at 28-30#. It's slightly low for my 23c road tires but 90psi will work fine if I I'm careful to avoid the potholes (does anyone TRY to hit potholes?).


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## SloDad (Sep 7, 2009)

I flatted on a century yesterday. I didn't get the 16g off in time and killed my spare tube. Lesson learned. Go with the 12g on a 700x23.


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## stevesbike (Jun 3, 2002)

12gram cartridge plus a mini-pump (one I have weighs about 50 grams). Use the pump to inflate to around 25psi and making sure tire is properly seated. Then use cartridge. That way you are safe against tube blowing off tire and have a pump for worst case scenario of multiple flats....


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## Kerry Irons (Feb 25, 2002)

*Pressure?*



SloDad said:


> I flatted on a century yesterday. I didn't get the 16g off in time and killed my spare tube. Lesson learned. Go with the 12g on a 700x23.


You destroyed your spare tube by getting it to 125 psi? Pray tell, how is this possible? There is not a tire out there that can't take that kind of pressure. I'm thinking "operator error."


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## DaveG (Feb 4, 2004)

*in theory*



Mel Erickson said:


> Innovations publishes this inflation chart. It's rule of thumb because most of us use 700c tires rather than 27" (wtf?) I've found that a 12g cartridge inflates my 700x23c tires to about 90psi and it inflates my 26"x2.1 mountain bike tires to 30psi. That's just fine for my mountain bike because I run tubeless at 28-30#. It's slightly low for my 23c road tires but 90psi will work fine if I I'm careful to avoid the potholes (does anyone TRY to hit potholes?).


I use 16g cartidges and I usually get to about 110psi with a 23c tire. I assume there is some loss/leakage there, but I have never had the situation where I over-inflated with a 16g cartridge. 12g's just does not get me there


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## dirtysprocket (Feb 9, 2006)

lamazion said:


> Well, the package on the 16 gram states 130 psi for a 23c tire. I went with the 12 gram because they were less than $1 each at Dick's sporting goods (the 16 gram were $7.99 for two).



Bike Tires Direct- 16gm for $1.95:thumbsup:


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## orangeclymer (Aug 18, 2009)

Purchased a box of 15 12g from wally world just a few days ago, cost = 54c each.


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## MerlinAma (Oct 11, 2005)

stevesbike said:


> 12gram cartridge plus a mini-pump (one I have weighs about 50 grams). Use the pump to inflate to around 25psi and making sure tire is properly seated. Then use cartridge. That way you are safe against tube blowing off tire and have a pump for worst case scenario of multiple flats....


Exactly. 

In fact my little pump works so well I'm almost convinced to abandon CO2 altogether.


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## SloDad (Sep 7, 2009)

Kerry Irons said:


> You destroyed your spare tube by getting it to 125 psi? Pray tell, how is this possible? There is not a tire out there that can't take that kind of pressure. I'm thinking "operator error."


Well Kerry Irons, you would be thinking wrong and posting it for everyone to see. Yes, there are tires that are rated for less than 125 psi. In fact, many are rated for 120. My Veloflex Pave are rated at a 115 psi max and have a very soft bead which comes off the rim pretty easily. And, as you can see from the huge chart above, a 16g will inflate a road tire to 130. But 16g were all I had, so I had to go with that. 

So, I'm thinking dumba** who tries to be a forum know-it-all and ends up looking stupid. Step up from $14 Nashar tires.


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## zac (Aug 5, 2005)

I use 16gram threaded exclusively on an ultraflate head. The trigger allows you to give a quick burst to seat the tube and tire and check it. If you get a bad mount you can deflate and still have enough gas to reseat and inflate.

With a straight inflate on a 16gr cart (of the times I have checked) I am getting about 100-110 psi. I have never had more than 115 and certainly never 130.

12s wouldn't do it for me as I run ~90psi in the front and ~110psi in the rear. This is on 700x23s. (Either Conty GP4000, Miche Pro2 or Pro3, Bonty RXLs or Spec. Armadillos).

Plus as was said, if you have a slow leaker, then the bigger cartridge will give you more gas on the way home.

Just a tip to keep your fingers from freezing to the cartridges: wrap them in cloth tape or use cut sleeves of old tubes to fit around them. Work wonders. Also look to get an inflator with a trigger as opposed to the ones that screw on with no regulator, as those blow so many tubes it's not funny. Also fill your tubes slow, this allows any pinches or twists or folds to work themselves out inside the tire, instead of blowing out the new tube.

zac


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## Kerry Irons (Feb 25, 2002)

*Dumba** response*



SloDad said:


> Well Kerry Irons, you would be thinking wrong and posting it for everyone to see. Yes, there are tires that are rated for less than 125 psi. In fact, many are rated for 120. My Veloflex Pave are rated at a 115 psi max and have a very soft bead which comes off the rim pretty easily. And, as you can see from the huge chart above, a 16g will inflate a road tire to 130. But 16g were all I had, so I had to go with that.
> 
> So, I'm thinking dumba** who tries to be a forum know-it-all and ends up looking stupid. Step up from $14 Nashar tires.


So it is your contention that a tire rated for 115 psi will blow off the rim if inflated to 130? I think you had better do a little reading on this subject. One concept to understand is called "safety factor." If a conventional 23mm road tire blows off the rim at 130 psi it is due to installation error, defective or damaged tire, or defective, incompatible, or poorly designed rim. A hook-bead tire will stay on the rim at full pressure even with the bead cut in several places.

And "$14 Nashbar tires" enters this discussion how?


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## TBaGZ (Jun 6, 2009)

I picked up a box of 20 threaded 16grm on Ebay for like 25 bucks shipped awhile back.


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## RonSchon (Jul 4, 2009)

SloDad - I've only bothered joining this site this year, but have been reading it for many years - perhaps you've done the same.

I have no idea who Kerry Irons is, but for a long time he has been helping noobs and veterans alike with technical bicycle information of value.

You were kind of harsh - I think an apology is in order.


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## SloDad (Sep 7, 2009)

RonSchon,
Thanks for the advise, but I'm far from a noob. I don't think Kerry was trying to help, I think he was trying to sound smart at some one else's expense. If he wanted to offer a helpful suggestion, he could have done that and I would have appreciated it. But he didn't, he just wanted to make me look incompetent. So, we'll have to agree to disagree on the apology.

The problem is that these particular tires have a very soft sidewall and bead and are quite difficult to get properly seated on the rim without a small amount of pressure in the tube. It is possible to pop the tire off the rim when trying to get these particular tires to seat properly with a completely deflated tube and a CO2 cartridge. I have never had a problem with any other tires and my current CO2 inflator, but these are fairly new, and the lesson learned was to go with a trigger regulated inflator like the Ultraflate that zac suggested. 

zac, thanks for the suggestion.


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## Mel Erickson (Feb 3, 2004)

SloDad, believe me, Kerry was trying to be helpful. He was questioning your claim that you destroyed your tube/tire with a 16g CO2. You have actually described what could be operator error in your post. Always partially inflate your tube before pumping it to full pressure. This does not have to be done with a pump or CO2 cart. You can simply blow into the presta valve. This does two things. It prevents the tube from being twisted when put into the tire and it helps insure it doesn't get pinched between the tire bead and rim when inflating. Could this have been your problem?

BTW, if you take the time to look you'll find Kerry is probably THE most helpul and THE most knowledgeable person on this board when it comes to bikes and bike repair. Diss this guy at your own risk because he's HIGHLY respected on this site. Maybe his post seemed a little harsh to you but he deals with problems like this, both mundane and complicated, all the time. We all have bad days and sometimes when you deal with similar problems time and time again you get a little short with your answers.


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## SloDad (Sep 7, 2009)

Mel, in all sincerity, thanks for your input. I did try to blow into the tube but there was no way to get enough pressure to hold the bead in place. Once I got a pump, it was an easy fix. Live & learn.


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## estone2 (Sep 25, 2005)

SloDad said:


> rant


The safety factor of which Kerry Irons speaks is that tires can go high above recommended. A fairly standard procedure to determine the max rated pressure for a tire is to pump it up to max pressure till it blows off the rim. You do this with several tires. You then take the lowest one of those, and you divide it by two. That's the "max" value posted on a tire.

In other words, your 120psi max tires can easily go to 150psi or more. That being said, just because you can doesn't mean you should.


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## Mel Erickson (Feb 3, 2004)

SloDad said:


> Mel, in all sincerity, thanks for your input. I did try to blow into the tube but there was no way to get enough pressure to hold the bead in place. Once I got a pump, it was an easy fix. Live & learn.


The point of partially inflating the tube is not to assist in seating the bead of the tire. It's to give the tube enough shape before installing it in the tire so it doesn't get twisted or pinched. If your bead doesn't seat properly when inflated with CO2 then there's either something wrong with the bead, an incompatibility between the bead and rim or operator error. Even with the type of CO2 inflator that only has a twist valve you can carefully crack it just enough to let in a small amount of CO2 and then check the bead before fully inflating. The type with the trigger works much better in this regard. My guess is your tires are faulty and were manufactured out of spec and got by quality control.


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## SloDad (Sep 7, 2009)

The whole key for me was not having a trigger-operated inflator. Bottom line is that I needed to control the flow of CO2. I definitely need to pick up a new inflator or a pump. 

Thanks for the info.


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## zac (Aug 5, 2005)

SloDad, I, equally have never met Kerry Irons, but, have been a member of RBR for a couple years now and his advise while often direct, is spot on.

Seriously, don't take offense, I don't think anyone in this thread felt he was dressing you down.

RBR tends to be a much better site with better advise, more passionate riders and fewer asses unlike that other popular site (BF) tends to be.

And to clarify like Mel has pointed out, the slight preinflate of the tube is just to give it shape and to keep it from getting pinched when you seat the tire. You can actually do this with your mouth and blow into the tube if that doesn't bother you. That way you are not wasting CO2. Is it really a necessary step? No, but it's just a "trick" that many of us use to make installing the tube a bit easier.

If you are blowing 700c x 23 tires off rims at 130 psi then there are a couple things to check: 
-Improper tire installation
-Improper tube installation
-broken or inaccurate tire pressure gauge
-wrong size tire or rim (both need to be 700c)
-defective tire.
-cracked rim

peace
zac


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## zac (Aug 5, 2005)

SloDad said:


> The whole key for me was not having a trigger-operated inflator. Bottom line is that I needed to control the flow of CO2. I definitely need to pick up a new inflator or a pump.
> 
> Thanks for the info.


I see that a lot even with pretty "experienced" riders who due to pride, go through their road stash of tubes and a couple of friends tubes before asking for help. An almost instantaneous inflate of a tube does a couple of bad things: One assuming it doesn't outright blow the tube b/c of a slight pinch or something, it freezes the valve open and the surrounding rubber of the tube which becomes rigid and cracks with that signature gun shot exclamation. Regulating the inflation rate keeps things a bit "warmer" and allows for the tube to move and fill the tire properly. Sure it can be done with a straight shot inflator, but the trigger makes it so much more easier.

Once you have the tire mounted on the rim with the tube inside do another slight partial inflate just so you can check around the rim on both sides to make sure the tube is not pinched between the rim and the tire bead. This will also either blow the tube or unmount the tire.


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## Eric S (Mar 29, 2006)

RonSchon said:


> SloDad - I've only bothered joining this site this year, but have been reading it for many years - perhaps you've done the same.
> 
> I have no idea who Kerry Irons is, but for a long time he has been helping noobs and veterans alike with technical bicycle information of value.
> 
> You were kind of harsh - I think an apology is in order.


+1, SloDad, you're of to a great start on this site.


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## Keeping up with Junior (Feb 27, 2003)

*Help?*



SloDad said:


> ...he just wanted to make me look incompetent...


No help needed there. Remember, you were the one that screwed up a tube change and inaccurately blamed the extra 4 grams of CO2. When called on that you came up with other reasons.


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## Mel Erickson (Feb 3, 2004)

The only time it can ever get cold enough to freeze the tube is of you hold the inflator so the cartridge is pointing down. In some cases this may allow a small amount of liquid CO2 to escape and freeze the valve/tube. Always inflate with the cartridge pointing up and it's virtually impossible to freeze the tube.


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## zac (Aug 5, 2005)

Mel Erickson said:


> The only time it can ever get cold enough to freeze the tube is of you hold the inflator so the cartridge is pointing down. In some cases this may allow a small amount of liquid CO2 to escape and freeze the valve/tube. Always inflate with the cartridge pointing up and it's virtually impossible to freeze the tube.


Didn't know Mel, thanks. 

But just wondering, couldn't the valve and surrounding rubber freeze (or rubber harden) due to conduction from the head unit? Or more likely, the sudden expansion of the gas. Its not the CO2 per se that is cold, it is the rapid expansion of a compressed gas. This is sort of a micro refrigerator, same principal as a heat pump.
I know my cartridges get cold, never really felt the need to touch the head end of the regulator, but wouldn't that get f'n cold too? I have seen the presta valves get frosty in the summer humidity, so I would think that it would be very likely that a valve could freeze or the surrounding rubber could get affected by the sudden temperature differential. I suppose it would be very difficult to freeze the tube, but perhaps that thin material undergoing such sudden and extreme temperature differential is going to be affected.


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## Mr. Versatile (Nov 24, 2005)

+1 on the Ultraflate. With the 16 g cartridges I can control it well enough to inflate the tube to the shape that makes it easier to stuff it in the tire. After the tire is on the rim, I give it a little harder shot so I can see if it's seated correctly. If it's not (and of course *mine ALWAYS are)*  & can let some air out, re-seat it, then inflate to the desired pressure. The trigger on the Ultraflate is extremely controllable & never freezes your hand.


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## brucear (Aug 23, 2007)

*co2*



Mel Erickson said:


> The only time it can ever get cold enough to freeze the tube is of you hold the inflator so the cartridge is pointing down. In some cases this may allow a small amount of liquid CO2 to escape and freeze the valve/tube. Always inflate with the cartridge pointing up and it's virtually impossible to freeze the tube.



I never thought of this rightside up for co2 cart., but 30 yrs ago I hauled bulk propane for delivery to residentual households. When the resident took the gas out of the top of the tank it was a gas for the homes appliances and bbq etc.. If they took it out of the bottem of the tank it was a liquid, they would fill there auto and they could get around paying road taxes at to local station.
I have been using a 16 gr theaded unit, but I have been looking online at bulk 100 cart prices of less than $.40 for 12 gr.unthreaded. I'm thinking of getting a trigger co2 unit and first pumping up the tire with 30-40 psi with a pump which I also take along anyway just to be safe. 
I'm also the type of person who will try to find a better way. There must be a way to install a inflation hose that I have to a very small reuseable co2 tank. I could filled at home or at the local paint ball store for the quoted price of $2.00. This sounds like it could be a money making invention.
I ride my Felt bike 33 miles most days and another to do my shopping around 10-30 miles a day most days. Doctors orders, they told me 4 years ago to loose at least 100 pounds. They informed me that ridding a bike was the best way to do it, I lost 130 pound and put 30,000 miles on the bikes,
Sarry for writing so much, Thanks, Brucear


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