Re: Helium Filled Tubes

<[email hidden]> wrote: (clip) I immediately noted the difference in a
smoother ride. (clip)
^^^^^^^^^^^^^^^
I think in a true blindfold test. you would not be able to tell the
difference. (semi-TIC)

Leo Lichtman said:

<[email hidden]> wrote: (clip) I immediately noted the difference in a
smoother ride. (clip)
^^^^^^^^^^^^^^^
I think in a true blindfold test. you would not be able to tell the
difference. (semi-TIC)

Campy equipped bikes ride best with air bottled in Vicenza, while
Shimano equipped bicycles should use air bottled at the summit of Mt. Fuji.

--
Tom Sherman - Near Rock Island

kbatzler said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires. Today, I had the air "removed" from
my new Jetta Wagon which has sport suspension and 17" wheels. I
immediately noted the difference in a smoother ride. Most of the posts
that I have read on the internet don't understand why there is any
benefit to using Nitrogen. Some sites state that it has something to
do with Boyle's Law. But, I found it has more to do with Dalton's Law
which states: Each gas exerts its own pressure. In formula: pv = nRT.
Because oxygen contracts and expands differently than Nitrogen and that
oxygen molecules are smaller than Nitrogen, it makes sense that the
pressure is more stable and less prone to leaks.

Ummm. Horseshit. What do you think "air" is, anyway? 75% of air, or
more, is precisely nitrogen. The rest is oxygen, carbon dioxide, and
farts.

--

David L. Johnson

__o | You will say Christ saith this and the apostles say this; but
_`\(,_ | what canst thou say? -- George Fox.
(_)/ (_) |

On 19 Jan 2005 18:30:12 -0800 said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires. Today, I had the air "removed" from
my new Jetta Wagon which has sport suspension and 17" wheels. I
immediately noted the difference in a smoother ride. Most of the posts
that I have read on the internet don't understand why there is any
benefit to using Nitrogen. Some sites state that it has something to
do with Boyle's Law. But, I found it has more to do with Dalton's Law
which states: Each gas exerts its own pressure. In formula: pv = nRT.
Because oxygen contracts and expands differently than Nitrogen and that
oxygen molecules are smaller than Nitrogen, it makes sense that the
pressure is more stable and less prone to leaks.

Is this a troll, or have you just never had a physics course?

-
-----------------------------------------------
Jim Adney [email hidden]
Madison, WI 53711 USA
-----------------------------------------------

Quoted message said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires. Today, I had the air "removed" from
my new Jetta Wagon which has sport suspension and 17" wheels. I
immediately noted the difference in a smoother ride. Most of the posts
that I have read on the internet don't understand why there is any
benefit to using Nitrogen. Some sites state that it has something to
do with Boyle's Law. But, I found it has more to do with Dalton's Law
which states: Each gas exerts its own pressure. In formula: pv = nRT.
Because oxygen contracts and expands differently than Nitrogen and that
oxygen molecules are smaller than Nitrogen, it makes sense that the
pressure is more stable and less prone to leaks.

My 2 cents,
Kbatzler

Quoted message said:

In germany cars use NO2 because it does not heat up like air and the

tire

Quoted message said:

pressure remains consistnt. I am told it produces a better ride. All

good

Quoted message said:

reasons when using a 17 MM bike tire on a track with 230 PSI in it.
Andrew Poodle wrote in message <[email hidden]>...

Quoted message said:

I believe (I may be wrong) that helium isn't used due to it's

molecular

Quoted message said:

size being so

Quoted message said:

small that your tyres would deflate quite quickly..

Just my tuppence worth

Andrew

Adam Simpson wrote:

> The reason Nitrogen is used in temperature-sensitive situations is

that

Quoted message said:

Quoted message said:

> nitrogen is quite insensitive to temperature changes and in the

case of

Quoted message said:

Quoted message said:

> racing tires, nitrogen will not burn in the presence of a spark.
> For the first reason stated, nitrogen is the best substance for

suspension

Quoted message said:

> damping because it is not sensitive to the temperature changes a
> shock may experience.
>
> ILuvMyCheV ([email hidden]) wrote:
> : "J. Michaels" <[email hidden]> wrote:
>
> : >20 years ago, some people used nitrogen in their car tires for

rally

Quoted message said:

events.

Quoted message said:

>
> : Without commenting on why, I can tell you that they still use it

in

Quoted message said:

road racing

Quoted message said:

> : tires. I was at the 24 Hours of Daytona this year and there was

an

Quoted message said:

area of the

Quoted message said:

> : pits where dozens upon dozens of N2 bottles were stored.
>
> : Aric Pogel
>
> --
> Adam Simpson (MTBfreak) / [email hidden]
> / [email hidden]

--
While you're spamming me, don't forget to include these guys:
Chairman Reed Hundt: [email hidden] Comm. James Quello:

[email hidden]

Quoted message said:

Quoted message said:

Comm. Susan Ness: [email hidden] Comm. Rachelle Chong:

[email hidden]

Quoted message said:

Quoted message said:

US Postal Service: [email hidden] Fraud Watch:

[email hidden]

Quoted message said:

Federal Trade Commission: [email hidden]

Oh, and while you're at it, pound some sand too!
admin@loopback $LOGIN@localhost $LOGNAME@localhost

$USER@localhost

Quoted message said:

Quoted message said:

$USER@$HOST -h1024@localhost [email hidden]

Dear K.,

You'd think that it has something to do with the size of the
molecules, but it doesn't.

The reason that pure N2 (78% in air) is preferred in tires
is that it isn't as soluble in rubber as the O2 (21% in air)
and much less soluble than CO2 (0.3% in air, but 100% in
quick-inflate cartridges).

You can see details and a link to why rubber balloons don't
hold air here:

http://groups.google.co.uk/groups?q=carl+nitrogen&hl=en&lr=&group=rec.bicycles.tech&selm=b8lms0prcs17q0jnr9q9ou9vq7qrqkt2fp%404ax.com&rnum=1

Helium party balloons, for example, have that familiar shiny
metal film because the gas hardly dissolves into metal at
all, but drools through rubber quite rapidly. The metal film
balloons are ugly, but they hold helium much longer than the
more attractive soft balloons.

Carl Fogel

may have said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires. Today, I had the air "removed" from
my new Jetta Wagon which has sport suspension and 17" wheels. I
immediately noted the difference in a smoother ride.

It is impossible for any gas to behave in a manner that is different
in any significant respect from any other gas at the same pressure in
a tire. If you noticed a difference, then the pressures were not the
same.

Quoted message said:

Most of the posts
that I have read on the internet don't understand why there is any
benefit to using Nitrogen.

That's because there isn't one in most cases.

Using a non-oxidizing fill gas in a tire is of benefit only when the
following conditions may obtain:

-- The tire has a heavy casing that may be able to heat up on the
interior surface to the point where the tire material begins to evolve
a combustible gas without losing sufficient structural integrity to
fail. (Automotive tires will generally fail well short of this
point.)

-- The tires are operated at a high enough pressure that the
accumulation of combustible gases as a result of extreme heating will
produce a mixture with sufficient energy production capability on
ignition to explode with force enough to shatter the tire.
(Automotive tires seldom operate at these pressures; it would be
difficult to achieve these conditions with only 35psi of normal air in
the tire.)

-- Some portion of the inflation cavity reaches ignition
temperature for the resulting mixture. (Once again, automotive tires
will fail before this point is reached.)

So, where is a nitrogen fill worthwhile? In large truck tires, some
construction equipment, some industrial equipment in
continuously-operated machinery, and large aviation tires.

In particular, on heavy trucks using dual wheels, the use of a
non-oxidizing fill gas will ensure that the failure mode for an
underinflated tire is nonexplosive. It should be noted that if the
conditions which could generate such an exlosion are in fact achieved,
the tire will fail due to the damage caused from the heating in any
event; this merely removes the additional hazard posed by the
explosion.

There is no benefit in using a nitrogen fill on any normal-profile
automotive tire, it is questionable if there is any benefit in using a
nitrogen fill in an ultra-low-profile tire since the pressure is not
high enough to support generation of an explosive force great enough
to damage the tire even if the highly unlikely set of conditions could
be achieved to cause that explosion, and the benefit in light truck
tires is probably minimal.

Quoted message said:

Some sites state that it has something to
do with Boyle's Law. But, I found it has more to do with Dalton's Law
which states: Each gas exerts its own pressure. In formula: pv = nRT.
Because oxygen contracts and expands differently than Nitrogen

This is an overstatement. The difference involved is so miniscule
that there is nothing to be gained which the vehicle operator could
possibly perceive. The condensation temperatures of the majority of
atmospheric gases are so far below STP that their behavior at normal
operating temperatures is essentially identical. Do the math and you
will confirm this.

Quoted message said:

and that
oxygen molecules are smaller than Nitrogen, it makes sense that the
pressure is more stable and less prone to leaks.

With few exceptions, molecular size has less of a bearing on gas loss
through a tire's casing than the solubility of the gas in the tire's
interior compounds. Tire interiors are formulated using polymers that
are selected for their resistance to atmospheric gas, so the subject
of what makes a good fill gas is rather moot; unless you were to
employ helium (which does, in fact, escape through the tire's casing
too readily), the rate of gas loss is quite small.

The common belief that air in tires escapes through the pores of the
rubber dates back to the days when tires were made of that material.
Today's automotive tires are not made of rubber; they are made from
complex polymer mixtures derived from petrochemical sources, and they
do not have the same properties as rubber in most areas. Yes, there is
still some gradual loss of air from automotive tires even with the
modern materials, but differential gas loss rates do not favor
nitrogen to any significant extent. The current fad for its use in
automotive tire inflation is just that; a fad. It is a valid
technique for preventing certain events in tires of higher pressure
ond stiffer construction if they are at risk of severe interior heat
buildup, but its value in automotive tires is entirely as a marketing
gimmick.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

On Wed, 19 Jan 2005 21:06:53 -0600, Tom Sherman

may have said:

Leo Lichtman said:

<[email hidden]> wrote: (clip) I immediately noted the difference in a
smoother ride. (clip)
^^^^^^^^^^^^^^^
I think in a true blindfold test. you would not be able to tell the
difference. (semi-TIC)

Campy equipped bikes ride best with air bottled in Vicenza, while
Shimano equipped bicycles should use air bottled at the summit of Mt. Fuji.

But in the case of air from Fuji, the air must be from the cycling
season. French bikes, of course, should only have their tires
inflated with Perri-air.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

Quoted message said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires.

You need to do more research.

a.) N2 is great in car tires used in performance applications for two
reasons:

1 - It's cheap as a compressed gas.

2 - Unlike compressed atmospheric air, it contains very little water
vapor.

b.) N2 is great in bike tires if you already have a source for your
auto tires because you don't have to physically manipulate a floor
pump.

c.) N2 exhibits non-ideal behavior WRT temperature changes. But the
range of temperature changes (in Kelvin) that an auto tire might
undergo is so small as to be insignificant, when compared to volume and
pressure.

But if you want your car (or bike) to be lighter, use He.
🙂

HAND,

E.P.

Quoted message said:

You'd think that it has something to do with the size of the
molecules, but it doesn't.

The reason that pure N2 (78% in air) is preferred in tires
is that it isn't as soluble in rubber as the O2 (21% in air)
and much less soluble than CO2 (0.3% in air, but 100% in
quick-inflate cartridges).

Are there any gasses whose thermal expansion rates would make them
less likely than air to cause bicycle tire blowoffs on steep descents?
-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

John Dacey said:

Quoted message said:

You'd think that it has something to do with the size of the
molecules, but it doesn't.

The reason that pure N2 (78% in air) is preferred in tires
is that it isn't as soluble in rubber as the O2 (21% in air)
and much less soluble than CO2 (0.3% in air, but 100% in
quick-inflate cartridges).

Are there any gasses whose thermal expansion rates would make them
less likely than air to cause bicycle tire blowoffs on steep descents?
-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

Dear John,

Nope.

Werehatrack explained this to kblatzler:

[kblatzler believed hopefully:]

Quoted message said:

Quoted message said:

Some sites state that it has something to
do with Boyle's Law. But, I found it has more to do with Dalton's Law
which states: Each gas exerts its own pressure. In formula: pv = nRT.
Because oxygen contracts and expands differently than Nitrogen

[werehatrack disillusioned him:]

Quoted message said:

This is an overstatement. The difference involved is so miniscule
that there is nothing to be gained which the vehicle operator could
possibly perceive. The condensation temperatures of the majority of
atmospheric gases are so far below STP that their behavior at normal
operating temperatures is essentially identical. Do the math and you
will confirm this.

At ordinary temperatures and modest pressures (the STP, or
standard temperature and pressure above), gas is pretty much
gas when it comes to how much it expands when heated.
Bicycle tires aren't cold enough or at a high enough
pressure to condense the gases into liquid form.

A 100 psi tire full of CO2 at 72F will reach the same
pressure as a tire full of plain air or pure N2 or helium
if the rim heats the gas to 200F.

The difference in heating rates of the gases due to
different masses would be negligible--compressed to 7
atmospheres, about 100 psi, the mass in the tire is only
about the mass of the air inside a modest shipping box.

In this case, pigs is pigs.

Carl Fogel

"John Dacey" wrote: Are there any gasses whose thermal expansion rates
would make them less likely than air to cause bicycle tire blowoffs on steep
descents?
^^^^^^^^^^^^^
Any gas that you are likely to put in your tire is close to "ideal." This
means that they all behave pretty much according to the perfect gas law, and
exhibit the SAME coefficient of thermal expansion. So the answer is "no."
If there is going to be a difference, it will be due to the thermal
diffusivity of the gas, which will affect the rate at which the heat
transfers from the rim. However, this will also affect the rate at which
the gas loses heat to the surroundings, so the solution of the problem will
be very complex. (And probably pointless.)

Leo Lichtman said:

"John Dacey" wrote: Are there any gasses whose thermal expansion rates
would make them less likely than air to cause bicycle tire blowoffs on steep
descents?
^^^^^^^^^^^^^
Any gas that you are likely to put in your tire is close to "ideal." This
means that they all behave pretty much according to the perfect gas law, and
exhibit the SAME coefficient of thermal expansion. So the answer is "no."
If there is going to be a difference, it will be due to the thermal
diffusivity of the gas, which will affect the rate at which the heat
transfers from the rim. However, this will also affect the rate at which
the gas loses heat to the surroundings, so the solution of the problem will
be very complex. (And probably pointless.)

Thank you.

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

Galahad Threepwood said:

On Thu, 20 Jan 2005 13:58:53 -0500, John Dacey
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

Are there any gasses whose thermal expansion rates would make them
less likely than air to cause bicycle tire blowoffs on steep descents?

Quoted message said:

At ordinary temperatures and modest pressures (the STP, or
standard temperature and pressure above), gas is pretty much
gas when it comes to how much it expands when heated.
Bicycle tires aren't cold enough or at a high enough
pressure to condense the gases into liquid form.

With qualifiers like "ordinary" and "modest" it has been hard to get a
handle on this. After all, we've seen that rim braking can generate
sufficient heat to re-liquify tubular adhesives, melt tubes and raise
pressure to the point of tire blowoff. Are those temps still ordinary
and modest? Thanks to you and Leo L for clarifying the matter.

Quoted message said:

A 100 psi tire full of CO2 at 72F will reach the same
pressure as a tire full of plain air or pure N2 or helium
if the rim heats the gas to 200F.

The difference in heating rates of the gases due to
different masses would be negligible--compressed to 7
atmospheres, about 100 psi, the mass in the tire is only
about the mass of the air inside a modest shipping box.

In this case, pigs is pigs.

Don't ever let Lord Elmsworth hear you say that.

John Dacey
Blandings Castle

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

quote= said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires.

You need to do more research.

a.) N2 is great in car tires used in performance applications for two
reasons:

1 - It's cheap as a compressed gas.

2 - Unlike compressed atmospheric air, it contains very little water
vapor.

b.) N2 is great in bike tires if you already have a source for your
auto tires because you don't have to physically manipulate a floor
pump.

c.) N2 exhibits non-ideal behavior WRT temperature changes. But the
range of temperature changes (in Kelvin) that an auto tire might
undergo is so small as to be insignificant, when compared to volume and
pressure.

But if you want your car (or bike) to be lighter, use He.
🙂

HAND,

E.P.[/QUOTE]

At 60 psi, your mountain bike tire is reduced by 18g/tire (that's over half an ounce), at 45 psi you save 14g/tire. You could save another gram with Hydrogen beyond He.

Along the lines gcsmchemist has alluded to- it is common to use nitrogen in race car tires, but that is to minimize moisture found in air. The water vapor causes pressure fluctuations as it vaporizes and condenses altering handling. Since bike tires aren't heating up as much with the sliding in turns, you don't have the same moisture issues. You could still save almost a gram/tire with the nitrogen instead of air.

John Dacey said:

Galahad Threepwood said:

On Thu, 20 Jan 2005 13:58:53 -0500, John Dacey
<[email hidden]> wrote:

Quoted message said:

Quoted message said:

Are there any gasses whose thermal expansion rates would make them
less likely than air to cause bicycle tire blowoffs on steep descents?

Quoted message said:

At ordinary temperatures and modest pressures (the STP, or
standard temperature and pressure above), gas is pretty much
gas when it comes to how much it expands when heated.
Bicycle tires aren't cold enough or at a high enough
pressure to condense the gases into liquid form.

With qualifiers like "ordinary" and "modest" it has been hard to get a
handle on this. After all, we've seen that rim braking can generate
sufficient heat to re-liquify tubular adhesives, melt tubes and raise
pressure to the point of tire blowoff. Are those temps still ordinary
and modest? Thanks to you and Leo L for clarifying the matter.

Quoted message said:

A 100 psi tire full of CO2 at 72F will reach the same
pressure as a tire full of plain air or pure N2 or helium
if the rim heats the gas to 200F.

The difference in heating rates of the gases due to
different masses would be negligible--compressed to 7
atmospheres, about 100 psi, the mass in the tire is only
about the mass of the air inside a modest shipping box.

In this case, pigs is pigs.

Don't ever let Lord Elmsworth hear you say that.

John Dacey
Blandings Castle

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

Dear John,

It is extremely unlikely that any any bicycle tire would
generate (much less survive) temperatures or pressures
sufficient to alter the behavior of one gas versus another.

Here's a page with a table of the Centigrade temperatures
and pressures in multiples of atmospheres at which some
common gases liquify:

http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch14/property.html

The boiling points in Centigrade are for 1 atmosphere of
pressure.

CO2, for example will liquify at a sweltering 31C, about
87F--if you also compress it to about 73 atmospheres, a
little over a thousand psi.

At normal air pressure, CO2 begins to boil at about -78C,
about -108F, so frozen CO2 (dry ice) just turns directly
from solid to gas at normal temperatures, skipping the
liquid state and sublimating.

B. Wooster

Quoted message said:

Quoted message said:

Quoted message said:

I have spent most of this night researching the benefits of using
Nitrogen in passenger car tires.

Quoted message said:

Quoted message said:

But if you want your car (or bike) to be lighter, use He.

meb said:

At 60 psi, your mountain bike tire is reduced by 18g/tire (that's over
half an ounce), at 45 psi you save 14g/tire. You could save another
gram with Hydrogen beyond He.

Along the lines gcsmchemist has alluded to- it is common to use
nitrogen in race car tires, but that is to minimize moisture found in
air. The water vapor causes pressure fluctuations as it vaporizes and
condenses altering handling. Since bike tires aren't heating up as much
with the sliding in turns, you don't have the same moisture issues. You
could still save almost a gram/tire with the nitrogen instead of air.

I half-followed this "nitrogen" thread. I think I might
have stumbled on its inception- Wall Street Journal's car
column had a question about it - answer noted that Costco
fills tires with nitrogen. Probably costs them little,
gives an opportunity to look 'tech' and so distinguish their
service dep't.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Quoted message said:

It is extremely unlikely that any any bicycle tire would
generate (much less survive) temperatures or pressures
sufficient to alter the behavior of one gas versus another.

Quoted message said:

CO2, for example will liquify at a sweltering 31C, about
87F--if you also compress it to about 73 atmospheres, a
little over a thousand psi.

I do a lot of work with track racers here. Some of them are already
using tire inflation that's flirting with 20% of that number. If only
those guys at Silca would put some real moxie in their floor pumps...

Quoted message said:

At normal air pressure, CO2 begins to boil at about -78C,
about -108F, so frozen CO2 (dry ice) just turns directly
from solid to gas at normal temperatures, skipping the
liquid state and sublimating.

It sounds like the stages through which many rbt threads go: direct to
gas without intermediate transitions.

-------------------------------
John Dacey
Business Cycles, Miami, Florida
http://www.businesscycles.com
Since 1983
Our catalog of track equipment: online since 1996
-------------------------------

"A Muzi" wrote: (clip) Costco fills tires with nitrogen. Probably costs
them little, gives an opportunity to look 'tech' and so distinguish their
service dep't.
^^^^^^^^^^^^^
Mental image of hammer hitting nail on head. :-)

On Fri, 21 Jan 2005 01:42:32 -0600, A Muzi <[email hidden]> may

have said:

I half-followed this "nitrogen" thread. I think I might
have stumbled on its inception- Wall Street Journal's car
column had a question about it - answer noted that Costco
fills tires with nitrogen. Probably costs them little,
gives an opportunity to look 'tech' and so distinguish their
service dep't.

Bingo. Marketing.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.