Why CO2?

General cycling advice ( NOT technical ! )
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Cunobelin
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Joined: 6 Feb 2007, 7:22pm

Re: Why CO2?

Postby Cunobelin » 11 Aug 2019, 2:54pm

Brucey wrote:


interesting and not very accurate. The main gist of it is correct but the diffusion rate of CO2 through rubber is definitely not 'minutely different' from that of air or N2; it is considerably higher.

cheers


As always ... raised as a discussion point

What you use is up to you , me I use an easily available mix of gasses ...78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Why CO2?

Postby Brucey » 12 Aug 2019, 12:46am

Samuel D wrote:Ah! If it had been the other way around we could have hoped for a bigger reduction in leakage over time.


...and a pretty good chance that your tyres might spontaneously combust....? :shock:

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

Samuel D
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Joined: 8 Mar 2015, 11:05pm
Location: Paris

Re: Why CO2?

Postby Samuel D » 12 Aug 2019, 10:06am

Brucey wrote:...and a pretty good chance that your tyres might spontaneously combust....? :shock:

With latex tubes you get to the point where you’d accept that risk to reduce the pumping! I’ll have to see if Vittoria has finally found a tangible benefit to graphene with the new latex tubes …

Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Why CO2?

Postby Brucey » 12 Aug 2019, 10:31am

its just as well O2 leaks faster than N2; the prospect of accidentally ending up with tyres that are largely filled with pressurised oxygen doesn't bear thinking about; the world would be a much more dangerous place.

All kinds of things that are generally fairly inert can auto-ignite in the presence of pure oxygen. For example Oxygen regulators may have an aluminium body, but are usually supplied with a brass flow path, 'for safety'. Nailing a different regulator onto an Oxygen cylinder (which is deliberately made difficult by incompatible threads) is a really dangerous thing to do. There have been many accidents including several notable ones, such as Apollo 1. More recently a small oxygen leak resulted in the destruction of an aircraft;

https://aviation-safety.net/database/record.php?id=20150616-0

Image

fortunately the fire broke out when the plane was on the ground.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~