The ridiculous myth about letting bike tyres down when flying.

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Alun

Guru
Location
Liverpool
I want to know why I can't listen to my iPod Nano on a plane... :scratch:
Because it will distract you from buying all the overpriced crap on the plane
 

BigAndyH

Guru
Location
Bournemouth
You also have the added safety of nitrogen being, as I mentioned before, an inert gas. Air contains, as well as nitrogen, oxygen, which is not an inert gas. Not only is it corrosive, in the form of a pure gas, it will spontaneously combust in the presence of petrochemicals, which are typically found in airplanes, in the wings, to which the landing gear is attached, and which most aircraft leak.
to sum up:
1. its non corrosive
2. its non flammable
3. it less likely to change its volume due to temp
4. it is less likely to change its volume at altitude.

For an ideal gas PV/T = constant, and since N2 is near enough an ideal gas for our purposes, and is the major component of air, its volume will change with temp and pressure in almost exactly the same way as for air.

Frankly the rules is stupid, even an unpressurised hold would not add 1 bar of pressure and would be a lot colder than the cabin so reducing pressure rather than increasing it. P.V/T remains constant so is you drop the temperature from 20C to -30C this is a drop of approximately 20% whereas a high pressure tyre at 100psi would only go up by 15% in a vacuum.

But temperature needs to be in Kelvin, so from 293 to 303 - a drop of only 3.4%, though in reality I'm sure the hold will get a lot colder than 20 C. The lower temp will reduce the gas volume, thus countering the effect of reduced pressure ( which will cause the gas to expand).
 
Normally the holds are heated, unless they are carying a stiffy, then the heating get turned off, and then not always, nothing worse than getting into the hold to find they have been cooking a stiffy for 13 hours. LOL Dont ahhf make them fart
 

steveindenmark

Legendary Member
I work on the premis that it is not my plane and if you come in my house you follow my rules.

It makes everyone so much happier.

Steve
 

rollinstok

Well-Known Member
Location
morecambe
There is a fundamental flaw in your argument.. bicycle tyres are not designed to handle 500mph. I have done an equation and calculated that 4.37% of the air pressure in any bicycle tyre should be exhausted via the valve prior to boarding the aircraft, regardless of recommended maximum pressure of said tyre. I work for the EEC therefore I am correct.
 

steveindenmark

Legendary Member
You mean like the rule:

You let your tyres down? :pump:

Steve
 
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