Bicycle Mechanics - Argon in tyres?

Having read a couple of threads about how various gases diffuse through the butyl rubber in tubes, I wonder if an inert gas would be better? Argon is fairly abundant and its atomic radius is pretty big as well, if that matters.

I hear air is pretty abundant, can be compressed by hand and is surprisingly affordable.

I prefer a mix with about 20.9 % oxygen in my tires. I hear its the best

The other two posters have it right but I still have to ask; what problem are you trying to solve?

Don't forget to put fresh air in your tires regularly!~! I ran nitrogen once in my 2wd truck. Absolutely no difference in my humble opinion.,,,,BD

Ah, FFS people, why does every thread here have to turn into stupid stuff like this?

Personally, I would never dream of using anything but a regular old pump to fill my tubes. I've never even used a CO2 thingy.

Can't you for one second think about something theoretically? Are you really that narrow in your thought processes, that you find that impossible?

View this as a question in the same vein as a question such as "Are we alone in the universe?"... :D

Ah, FFS people, why does every thread here have to turn into stupid stuff like this?
Because the threads start with questions like this?

Personally, I would never dream of using anything but a regular old pump to fill my tubes. I've never even used a CO2 thingy.
Ah, a theoretical technical discussion about "thingys".

Can't you for one second think about something theoretically? Are you really that narrow in your thought processes, that you find that impossible?
Yes, it's true. I am mired in pragmatism. I need to watch more Star Trek or something.


View this as a question in the same vein as a question such as "Are we alone in the universe?"... :D
Good question. Given threads like this, there has to be more intelligent life out there somewhere.

View this as a question in the same vein as a question such as "Are we alone in the universe?"... :D
Well, the questions about the gases used in bike tires can be tested for effect using currently available technology. The "are we alone in the universe" questions will require some additional development time. :)

Race cars use pure nitrogen in those tires because ambient air can have too much moisture. When that moisture boils, you can have all kinds of problems. We cyclists never deal with anything close to those kinds of speeds and cornering forces. The same can be said of our street cars.

Argon is a bit pricey to be filling bike tires. i'll stick to using my argon with my tig welder

Forget the practicalities and focus on the chemistry and physics of it.

I fill my tires with chocolate, that way when it punctures I get a delicious treat as well.

it is the concentration of these trace gases that causes the greenhouse gas problem. The trace gases are made up of Argon, Carbon Dioxide, Neon, Helium, Methane, Hydrogen, Nitrous Oxide and Ozone.
From here. (http://www.global-greenhouse-warming.com/greenhouse-gas.html)
There goes my personal methane recycling idea...:rolleyes:

I can forget about NAWS for my bike too. :(

From here. (http://www.global-greenhouse-warming.com/greenhouse-gas.html)
There goes my personal methane recycling idea...:rolleyes:

I can forget about NAWS for my bike too. :(

you just gave me a brilliantly awesome, evil idea to carry out on unruly customers.

aron is still smaller than CO2

I fill my tires with chocolate, that way when it punctures I get a delicious treat as well.

Haha..

"Need help with that flat?"
"Need some CHOCOLATE, BABY!!!!?"

It's gonna slow you down: argon has a density of 1.784 kg/m3 while air's density is 1.2 kg/m3. Think of all that extra mass to accelerate.

Race cars use pure nitrogen in those tires because ambient air can have too much moisture. When that moisture boils, you can have all kinds of problems. We cyclists never deal with anything close to those kinds of speeds and cornering forces. The same can be said of our street cars.
I'd have gone with aircraft use it because of the fire *********** in case of blowout, and race cars followed suit, but hey...

I thought race cars use Nitrogen because it doesn't expand from heat as much as ambient air???

aron is still smaller than CO2

Size isn't the only factor -- polarity will affect the diffusivity as well.

I think you should fill your tubes with UF6, which has a very low speed of sound. That way, everytime you braked you'd get little sonic booms in your tires.

**for all you physicists out there: yes, I know. work with me here...

http://www.straightdope.com/columns/070216.html

aron is still smaller than CO2


aron who?

Personally I consider it highly important to change out the air every Spring and Fall.
alf

View this as a question in the same vein as a question such as "Are we alone in the universe?"... :D

We ARE the Universe, and the universe is us. Any attempt to classify or organize various parts of it are purely arbitrary.

It's gonna slow you down: argon has a density of 1.784 kg/m3 while air's density is 1.2 kg/m3. Think of all that extra mass to accelerate.

D'oh! What was I thinking!? :D

What about Helium? Would that make for a lighter ride?

I thought race cars use Nitrogen because it doesn't expand from heat as much as ambient air???

Yeah but the temps on their tires are like 100 celsius+.

What about Helium? Would that make for a lighter ride?

Helium is rare, non-renewable and the supply will gradually decrease and almost no helium will be available commercially within decades or up to a century or so, it is predicted.

Argon stays in the atmosphere and is also pretty common (More than 0.9% of the air is argon).

It's gonna slow you down: argon has a density of 1.784 kg/m3 while air's density is 1.2 kg/m3. Think of all that extra mass to accelerate.Hmm... good point. I think you want the measurement criteria of pressure per weight. So compare the partial vapour-pressure of argon and its weight vs. CO2 vs. ambient air. The water-vapour in air can allow you to reduce the amount and weight needed tremendously if you keep it at 100-C and above.. ;)

Because the threads start with questions like this?

Ah, a theoretical technical discussion about "thingys".

Yes, it's true. I am mired in pragmatism.

I can be as flip as the next guy, but this is "thread crapping", pure and stinky. If the topic doesn't interest you, then post elsewhere.

As I recall, the issue with increased diffusion of some gases had to do with the solubility of those gases in the case material (rubber). And from my chemistry, I recall that solubility is generally determined by the shapes and local charges of the molecules. Since argon is chemically inert, it essentially has no shape or local charges, so it is effectively insoluble.

Doesn't mean that it won't diffuse through the structure, or leak. But I bet it would do so at a slower rate than other gases (except krypton, xenon, or radon ;) ).

As I recall, the issue with increased diffusion of some gases had to do with the solubility of those gases in the case material (rubber). And from my chemistry, I recall that solubility is generally determined by the shapes and local charges of the molecules. Since argon is chemically inert, it essentially has no shape or local charges, so it is effectively insoluble.

Doesn't mean that it won't diffuse through the structure, or leak. But I bet it would do so at a slower rate than other gases (except krypton, xenon, or radon ;) ).

Yes, that is what I thought as well, and what I had in mind when I posted. However, my knowledge of chemistry is limited, so I wanted more opinions. :)

I fill my tires with chocolate, that way when it punctures I get a delicious treat as well.


Do you try and ride through Strawberry Fields Forever ?

As I recall, the issue with increased diffusion of some gases had to do with the solubility of those gases in the case material (rubber). And from my chemistry, I recall that solubility is generally determined by the shapes and local charges of the molecules. Since argon is chemically inert, it essentially has no shape or local charges, so it is effectively insoluble.

Doesn't mean that it won't diffuse through the structure, or leak. But I bet it would do so at a slower rate than other gases (except krypton, xenon, or radon ;) ).

I think there are two issues here, for the technically inclined. First, how soluble is a gas in rubber tires? Second, how fast do the gas molecules move through the rubber once it is taken up in the rubber -- that is, what is its diffusivity? These are both functions of the gas's and the polymer's (in this case, rubber) chemical composition, as DMF pointed out, but are fundamentally two different properties. When these two factors are combined, engineers refer to the overall permeability, which is the mass flux (of the gas through the rubber in this case) per unit area per unit time, normalized according to the pressure drop across the rubber.

I did some google searching, and found a paper: Barrer, R.M. "Permeation, diffusion, and solution of gases in organic polymers." Trans. Farad. Soc. 35 628 (http://www.rsc.org/ejarchive/TF/1939/TF9393500628.pdf). It shows that the permeability of argon -- and thus how fast it will leave through the tire rubber, given the same pressure, tire thickness, etc. -- is about three times that of nitrogen. The units for this permeability look a bit goofy, but just take note that the outflow rate would be measured in "moles" or number of molecules, because it is this that determines pressure in the tire.

Some of the replies to this post indicated it might be a waste of time. Don't worry, OP, I think it's an okay question! In fact, I can remember an exam question some time ago regarding patents that Air Products, Inc., (in Allentown, Pa.) had filed for a gas that could be used to pressurize tennis balls. They claimed that the gas increased the usable life of the tennis balls by a factor of two or something like that. I guess I would argue that questions like these, then, can be fruitful/significant!

[EDIT: The tennis ball invention is US Patent 4,358,111.]

I think there are two issues here, for the technically inclined. First, how soluble is a gas in rubber tires? Second, how fast do the gas molecules move through the rubber once it is taken up in the rubber -- that is, what is its diffusivity? These are both functions of the gas's and the polymer's (in this case, rubber) chemical composition, as DMF pointed out, but are fundamentally two different properties. When these two factors are combined, engineers refer to the overall permeability, which is the mass flux (of the gas through the rubber in this case) per unit area per unit time, normalized according to the pressure drop across the rubber.

I did some google searching, and found a paper: Barrer, R.M. "Permeation, diffusion, and solution of gases in organic polymers." Trans. Farad. Soc. 35 628 (http://www.rsc.org/ejarchive/TF/1939/TF9393500628.pdf). It shows that the permeability of argon -- and thus how fast it will leave through the tire rubber, given the same pressure, tire thickness, etc. -- is about three times that of nitrogen. The units for this permeability look a bit goofy, but just take note that the outflow rate would be measured in "moles" or number of molecules, because it is this that determines pressure in the tire.

Some of the replies to this post indicated it might be a waste of time. Don't worry, OP, I think it's an okay question! In fact, I can remember an exam question some time ago regarding patents that Air Products, Inc., (in Allentown, Pa.) had filed for a gas that could be used to pressurize tennis balls. They claimed that the gas increased the usable life of the tennis balls by a factor of two or something like that. I guess I would argue that questions like these, then, can be fruitful/significant!

[EDIT: The tennis ball invention is US Patent 4,358,111.]

We're talking about butyl tubes though, not rubber tires.

I can be as flip as the next guy, but this is "thread crapping", pure and stinky. If the topic doesn't interest you, then post elsewhere.
Busted again. I'll have to find another thread to recycle methane in. :rolleyes:

I thought race cars use Nitrogen because it doesn't expand from heat as much as ambient air???

I was too precise. The moisture causes the expansion. Been there, done that.

We're talking about butyl tubes though, not rubber tires.

Both organic polymers. ;)

Yes, that is what I thought as well, and what I had in mind when I posted. However, my knowledge of chemistry is limited, so I wanted more opinions. :)

To heck with theory. Got an argon tank? Air/argon up a couple tires and let them leak down. Then reverse them.

Plot the pressure decrease over time. Then we can puzzle about the results. In this wise are theories born (and buried).

Busted again. I'll have to find another thread to recycle methane in. :rolleyes:

Don't make me post the [Global Warming == Cow Farts] picture! http://www.thesmilies.com/smilies/surprised/wide-eyed.gif (http://www.thesmilies.com)

Got an argon tank?

Nope. http://www.bikeforums.net/images/smilies/biggrin.gif

Easily over $200 for a normal size tank, and about $25-$30 to fill it. I have an argon/C02 welding tank, on my welder of course, lol.,,,,BD

.......regarding patents that Air Products, Inc., (in Allentown, Pa.) had filed for a gas that could be used to pressurize tennis balls. They claimed that the gas increased the usable life of the tennis balls by a factor of two or something like that. I guess I would argue that questions like these, then, can be fruitful/significant!

[EDIT: The tennis ball invention is US Patent 4,358,111.]
The difference is tennis balls don't have valves and can't be repressururized so reducing pressure decay is a big issue.

Bike tubes can be refilled as often as you need to, including daily for high-pressure track tires with latex tubes.

Helium.

Lots of Helium.

Edit: Just realized this was already suggested.

Helium is rare, non-renewable and the supply will gradually decrease and almost no helium will be available commercially within decades or up to a century or so, it is predicted.

Argon stays in the atmosphere and is also pretty common (More than 0.9% of the air is argon).Well, comparing these gases to the currently used fresh air, all of these are unreasonable as they are not practical. A simple pump of air is. The benefit weight wise of any other gas is probably not worth the trouble.

Helium is rare, non-renewable and the supply will gradually decrease and almost no helium will be available commercially within decades or up to a century or so, it is predicted.

The question was theoretical - I'm not likely to go start trying to fill my tires with helium and if I where it would not likely be on a regular basis due to the cost of air (free) versus helium (not free). Given the theoretical nature of the question - renew-ability is moot point.

The difference is tennis balls don't have valves and can't be repressururized so reducing pressure decay is a big issue.

Bike tubes can be refilled as often as you need to, including daily for high-pressure track tires with latex tubes.

True, good point. I think air is indeed the best thing for bicycle tires, and my point was that argon would seep out faster than air through tubes, probably due to its smaller size. I was just pointing out that the OP's question wasn't totally out there.


What about Helium? Would that make for a lighter ride?

I figure the weight savings would be about 8 g per tire for 27"x1" tires at 100 psig. As was pointed out, however, helium is becoming more scarce, so don't tell the WWs....

Helium, though normally uncharged and non-reactive, is one of the most difficult gases to contain. You'd have to refill your tires more often than with regular air, or nitrogen, or argon even, possibly during the course of a longer ride.
I'm sure the He tire fill's been tried by racers; I don't think it would be such a hot idea though.
I think there was something like this on another thread.

I figure the weight savings would be about 8 g per tire ... helium is becoming more scarce, so don't tell the WWs....

:D

This thread is toast...

Helium, though normally uncharged and non-reactive, is one of the most difficult gases to contain.
I would argue that methane is even more difficult to contain, especially when one's finger is pulled.