CO2 Tire Inflator Cartridges -- Any risk from heat?

[TestPilot]

Do you carry a air compressor or Co2 in your car or truck? Probably not! Unless you are planning on riding off road hundreds of miles away from civilization, if you need a little air, stop at a gas station.

Good on you. I have had flats on 3 long tours, and in each case my repair kit has worked great. 1st time used 3 CO2 cylinders to get approx 20psi in rear - thereafter switched to carrying a compressor. And, as pointed out earlier - car & 4WD have spare wheels.

 

[Fred W]

My 12g cartridges have a printed upper temp limit of 120 deg F. Like others here, I have had them in my shiny black plastic bags in the summer heat of Palmdale, CA (read California high desert) without incident.
There is another item relating to CO2 that you might keep in mind. It has a different expansion characteristic than dry air does. It tends to increase its pressure MORE than air for the same increase in temperature ALL OTHER THINGS HELD THE SAME.

When you fill your tire with CO2 from a cartridge, the gas temperature at fill is pretty low. If you fill it to the std riding pressure, you could seriously over pressure the tire once it gets up to riding temp. Here is some interesting data:

Comparing air vs. CO2:

Working gas: dry air

Fill temp: 90 deg F

Fill pressure: 40 psi

Running temp: 130 deg F

Resulting pressure: 45.0 psi

Process: polytropic perfect gas with n = 2.5

Working gas: dry CO2

Fill temp: 50 deg F

Fill pressure: 40 psi

Running temp: 130 deg

Resulting pressure: 51.0 psi <---- see this...be advised!!

Process: polytropic perfect gas with n = 2.5

So anyway, keep the cold pressure down to somewhere between 30 & 35 psi during fill and replace with dry air when you get the chance. You might also want to recheck the pressure once everything has had a chance to stabilize thermally.

Cheers,

W2

Who fills their tires at 90F? :blink:

I'd venture to say, nobody around these latitudes. Most mornings when I'm checking my cold air pressure on my tires it is at ~60F. And I fill that rear to 42. So where does that put me after the tire still heats up during use?

 

[Bounce]

My tire repair kit has changed over the years. Currently it has both a pump and about 8 CO2 carts (with the applicator) along with both mushroom and sticky string plugs and the gun from Plug-and-Go for installing the 'shrooms. It all fits in a Quarter Cube and stays in a saddle bag. I've carried that think in up to 120 degree jaunts and into sub-freezing shivers without any mishaps.

The idea is that the pump, while slow, will help me find a leak if it's hiding. Then, after plugging, the CO2 will do the majority of the quick inflation. The different plugs should work across a wider selection of punctures.

Since building up the kit the only time I've needed it was for other people's flats (knock wood).

 

[FJR919]

On the FJR I carry a compressor. On the bikes that don't have the storage capacity, I carry CO2 cartridges. I got a flat 30 miles from home on my Honda 919. Repaired it with sticky strings and 3 or 4 CO2 cartridges. I drove home with no problems although slower than I normally ride.

 

[Geezer]

I carry both the mushroom plug kit with CO2 and the sticky string tools and strings. I have never used the mushrooms. For a compressor, I carry a bicycle pump. It takes a while to get enough air in the tire to ride it to a service station where air is available, but it works and I only needed it once in 80K miles.

 

[Wee Willy]

Who fills their tires at 90F? :blink:

Oh, I don't know...I just picked numbers that were within the bounds of my experience (gets over 100 out here routinely) to make the case that we CO2 users should pay attention to the bloody details. Actually, 90 can be on the low side. Consider this: if I'm pumping air into a tire using a gadget that intakes from 90 degree ambient conditions (hand pump for instance) then the air going into the tire will be even warmer than ambient once it settles because of the losses (think friction, etc.) AND the increased pressure from the work done in getting the gas from outside, through the pump and into the tire. So, you see, it's not so far fetched after all.

Just wanted to give the folks a head's up, s'all. :dirol:

To answer to your other question:

I'm checking my cold air pressure on my tires it is at ~60F. And I fill that rear to 42. So where does that put me after the tire still heats up during use?

Considering a polytropic process with n=2.5 again ( <--- this is really the number you might want to challenge...it assumes a lot about what's being modeled here and drives the answer at least as hard as the temperatures), if you fill to 42 psi and the gas' initial temp is 60 deg F then encounter a condition while riding where the gas in your tire rises to 130 deg F, you COULD potentially see a pressure of almost 52 psi.

It is really the DIFFERENCE between the fill and operating temperatures that is the first-order driver here. CO2 gas out of a cartridge is quite cold. Indeed, the cartridge itself gives you an idea of just how cold as it frosts up. And it'll be warmer than the gas is...it has more thermal mass to cool down.

Cheers,

W2

 

[old Pilot]

I'm thinking of sticking some CO2 tire inflator cartridges (along with a tire plug device) under the seat in my FJR. Does anyone know whether those cartridges have any risk of rupture/explosion/whatever if they are left in that kind of environment (ie, possibly hot, certainly bumpy) for a long time?

Doubt it. Have used self-inflating life jackets (CO2 cartridges) while sailing in direct sunlight in some damned hot weather for weeks on end. In the life jackets the CO2 cartridge is riding just over your chest or belly. Have not witnessed anyone spontaneously exploding while sailing....yet.

 

[Wee Willy]

The community owes you a beer. :drinks:

Excellent RH, thanks. I accept. With almost 7,500 members here, if even only a third of them pony up then I'll be in beer for sometime to come.

Cheers,

W2

 

[RadioHowie]

Who fills their tires at 90F? :blink:

C'mon, Fred...right now it's 90F here in CenFla. Where the hell did Spring go?

 

[Wee Willy]

...used 3 CO2 cylinders to get approx 20psi in rear - thereafter switched to carrying a compressor.

I have used 8 12g cartridges to fill the rear back to something like 33 psi cold. Some of the gas was lost during cartridge install and during attach to the stem...maybe 10% of the mass at worst. One of the 8 was a bit flat too.

Like you, I am now looking to get a compressor...the Motopump looks like a winner.

Cheers,

W2

 

[na1g]

All those who have had a CO2 cartridge explode under their seat, raise your hand. Umm, I don't think we have a problem Houston.

pete

 

[majicmaker]

I've carried the Stop&Go Gun with Mushroom Plugs and an 8pack of Co2 Cartridges for years now.

They work great and are Easy Peasy to use. Never had to use it for myself but, I've saved the day for many of my buddies. :clapping:

When I rescued them from the end of their ride, My beer was provided to me for FREE for the rest of the day!! They are worth their weight in GOLD!! :drinks: