Nitrogen to fill tires?

"Randolph" > wrote in message
...
>
> Zon wrote:
>
> <snip>
>
>> Hydrogen is different thing, but it is hard to
>> believe anyone would use it to fill tires
>
> Hard to believe someone would fill a dirigible with Hydrogen too :-)


Oh...the humanity!!!!!!!!

In ,
Matt O'Toole > decided to enlighten our sheltered souls
with a rant as follows
> Pete M wrote:
>
>> Citroens don't have air suspension. They have hydropneumatic
>> suspension. Filled with the lovely LHM fluid, not air.
>
> What's the pneumatic for in hydropneumatic then? Lift the lid of
> your Citroen, and look for that round thing on top of the shock tower.

The sphere, hmm, I know where you're coming from, but still not air
suspension really is it?

>
> BTW, LHM was great for old Judy forks.


I haven't forked Judy for ages.


--
Pete M

Mercedes 260E, BMW 540iSE, 730iSE (BMWs for sale)
Ford Capri (ressurection started)
"Never moon a werewolf"

COSOC #5
Scouse Git extraordinaire. Liverpool, Great Britain

"Pete M" > wrote in message
...
> In ,
> Matt O'Toole > decided to enlighten our sheltered souls
> with a rant as follows
>> Pete M wrote:
>>
>>> Citroens don't have air suspension. They have hydropneumatic
>>> suspension. Filled with the lovely LHM fluid, not air.
>>
>> What's the pneumatic for in hydropneumatic then? Lift the lid of
>> your Citroen, and look for that round thing on top of the shock tower.
>
> The sphere, hmm, I know where you're coming from, but still not air
> suspension really is it?

Technically no, it's a gas suspension as the spheres have nitrogen! The
compressed gas *is* the spring though, the fluid being there to transmit the
force of the rising wheel to the compressed gas within via a diaphragm. The
fluid passes through various restrictive ports to provide compression and
rebound damping. Very basic explanation over.
Almost identical in basic theory to the old British Leyland Hydragas
suspension as developed by Moulton.
Badger.

"Dori A Schmetterling" > wrote in message
...
> Just curious: where did you find this data?
>
> My (rather old 1972) 53rd ed Handbook of Chemistry and Physics apparently
> gives only bond lengths (p F-181).
>
> I am sure if I spent more than the 5 min spent so far with Prof Google I
> would find the answer, too....
>
> DAS

We could speculate that diffusion of a gas (N2 or O2) across a layer (rubber
and/or a composite thereof) is affected by other things than simply molecule
size. Cheifly I would expect affinity, or lack thereof, O2 and N2 molecules
to rubber molecules would be important.

More importantly I would think, if oxidation occurs with the inner rubber,
than those molecules are no longer available as a gas and would reduce the
pressure even if zero O2 molecules actually escaped the tire. Clearly if
there is any oxidation at all, O2 molecules are at least somewhat reactive
to rubber and perhaps are more likely to permeate the surface.

-Russ.

Pete M wrote:

> The sphere, hmm, I know where you're coming from, but still not air
> suspension really is it?

Absolutely.

Matt O.

In ,
Matt O'Toole > decided to enlighten our sheltered souls
with a rant as follows
> Pete M wrote:
>
>> The sphere, hmm, I know where you're coming from, but still not air
>> suspension really is it?
>
> Absolutely.

Pah, I class air suspension as suspension where the car is held up with air
springs.

Not where it's held up with a hydropneumatic system :-p

--
Pete M

Mercedes 260E
Ford Capri (ressurection started)
"Never moon a werewolf"

COSOC #5
Scouse Git extraordinaire. Liverpool, Great Britain

"Pete M" > wrote in message
...
> In ,
> Matt O'Toole > decided to enlighten our sheltered souls
> with a rant as follows
>> Pete M wrote:
>>
>>> The sphere, hmm, I know where you're coming from, but still not air
>>> suspension really is it?
>>
>> Absolutely.
>
> Pah, I class air suspension as suspension where the car is held up with
> air springs.
>
> Not where it's held up with a hydropneumatic system :-p
>
And as I already said, the fluid is merely transmitting the load from the
suspension connection point to the pneumatic side.
Get a grip of what is going on instead of trying to re-write the rule book.
badger.

"DRP535" > wrote in message
news
> On Mon, 03 Jan 2005 19:18:24 -0600, Kevin Oberle >
> wrote:
>
>>I was just at my friendly neighbourhood Costco and saw a sign advertising
>>that they can fill your tires with nitrogen instead of ordinary air. This
>>is something I've never heard of, though if the idea has trickled down to
>>Costco it must have been around for a while.
>>
>>What are the benefits of using N2 in one's tires?
>>
>>Kevin
>
> What everyone has failed to mention so far is how do they get the air
> *out*
> of the tyre in the first place to replace it with "pure" nitrogen?
>
> When you mount a tyre to a rim you don't do it in a vacuum do you? The
> tyre
> is already filled with air (and all that contains) before you've even put
> a
> pump nozzle on the valve. Big tyres like those on airplanes and dragsters
> contain a *lot* of air. You can't get a tyre inflated with pure Nitrogen
> no
> matter what you do.

Yes, of course they pull a vacuum on the mounted tire first... NOT!

MaltHound

"The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in message
...
>
> "DRP535" > wrote in message
> news
>> On Mon, 03 Jan 2005 19:18:24 -0600, Kevin Oberle >
>> wrote:
>>
>>>I was just at my friendly neighbourhood Costco and saw a sign advertising
>>>that they can fill your tires with nitrogen instead of ordinary air.
>>>This
>>>is something I've never heard of, though if the idea has trickled down to
>>>Costco it must have been around for a while.
>>>
>>>What are the benefits of using N2 in one's tires?
>>>
>>>Kevin
>>
>> What everyone has failed to mention so far is how do they get the air
>> *out*
>> of the tyre in the first place to replace it with "pure" nitrogen?
>>
>> When you mount a tyre to a rim you don't do it in a vacuum do you? The
>> tyre
>> is already filled with air (and all that contains) before you've even put
>> a
>> pump nozzle on the valve. Big tyres like those on airplanes and dragsters
>> contain a *lot* of air. You can't get a tyre inflated with pure Nitrogen
>> no
>> matter what you do.
>
> Yes, of course they pull a vacuum on the mounted tire first... NOT!
>
> MaltHound
Would it not be right to assume though that they are compressing the
original 28% of "gasses other than nitrogen" (Very "ish" %, before I get
flamed by those with simple minds and nothing better to do!!) into roughly
20-30% of its original volume? Therefore the "impurity" % drops to around
4.5-7.5%??? Ok, not 100% pure Nitrogen, but better than air (for all the
previously quoted reasons)? And the purity % would surely increase every
top-up with pure n2.
Badger.

"Badger" > wrote in message
...
> Would it not be right to assume though that they are compressing the
> original 28% of "gasses other than nitrogen" (Very "ish" %, before I get
> flamed by those with simple minds and nothing better to do!!) into roughly
> 20-30% of its original volume? Therefore the "impurity" % drops to around
> 4.5-7.5%??? Ok, not 100% pure Nitrogen, but better than air (for all the
> previously quoted reasons)? And the purity % would surely increase every
> top-up with pure n2.

The racer-X guys probably do it via a fill/purge/fill process.
Fill with pure N2. Then deflate them but maintain some small positive
pressure. Repeat. The more times that you repeat the better the purity.

But the only thing we seem to have agreed upon is that pure N2 will have no
moisture. The same could be said for a good source of dry air and is much
cheaper.

MaltHound