# Deflate tires for airline travel??



## vetboy (Oct 11, 2005)

I did a quick search but didn't see it mentioned. For those who have travelled with their bikes on airlines, do you deflate your tires beforehand. Woiuld the decrease in air pressure in the luggage area of the plane cause the tires to explode during flight??

I'm flying out tomorrow (Tour of Cali here I come) and wondering??

Joe


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## Blue CheeseHead (Jul 14, 2008)

I flew with mine inflated (110-120 psi) and had no issues. (Pro2Race, rated for 116psi max)


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## paul2432 (Jul 11, 2006)

vetboy said:


> I did a quick search but didn't see it mentioned. For those who have travelled with their bikes on airlines, do you deflate your tires beforehand. Woiuld the decrease in air pressure in the luggage area of the plane cause the tires to explode during flight??
> 
> I'm flying out tomorrow (Tour of Cali here I come) and wondering??
> 
> Joe


Assuming the cargo hold is at the outdoor air pressure, the increase in differential pressure would be at most 10-11 psi. That would not be enough to burst your tires unless they are close to bursting to begin with. Furthermore, assuming the cargo hold is not heated, the reduced temperature would reduce the tire pressure (outdoor air temperature at 37000 feet is around -50F).

Paul


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## merckxman (Jan 23, 2002)

Traveling to Italy on Alitalia they checked the tires to be sure they were deflated.


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## bigpinkt (Jul 20, 2006)

vetboy said:


> I did a quick search but didn't see it mentioned. For those who have travelled with their bikes on airlines, do you deflate your tires beforehand. Woiuld the decrease in air pressure in the luggage area of the plane cause the tires to explode during flight??
> 
> I'm flying out tomorrow (Tour of Cali here I come) and wondering??
> 
> Joe


I travel with mine 5-10 times a year. I never deflate them and have not had an issue. One thing though is do not bring Co2's with you. They say not to do it but I still used to bring them anyway. Then one time they opened my case after I checked it in, took my Co2's out and left me a note never to do it again. I don't do it anymore.


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## JCavilia (Sep 12, 2005)

*Do the numbers*

Think about it. Sea-level atmospheric pressure is about 15 psi. If your tires are inflated to 120 psi relative pressure at sea level, and you took them up to the space station and exposed them to near-vacuum, the relative pressure would rise to 135 psi. That would not be enough to blow the tires off. 

Anyway, the cargo holds of airliners are pressurized just like the passenger compartment (the big aluminum cylinder of the fuselage is the pressure vessel -- it would be way more complicated and mechanically stressful to pressurize only part of it.) So the pressure change will only be like climbing to 8,000 feet or so, which is a drop of maybe 4 pounds.

Anyway, cargo holds aren't always heated as much as the passenger compartment, so the temperature drop would offset some of the pressure change.

Have a nice trip.


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## android (Nov 20, 2007)

vetboy said:


> Woiuld the decrease in air pressure in the luggage area of the plane cause the tires to explode during flight??
> 
> I'm flying out tomorrow (Tour of Cali here I come) and wondering??
> 
> Joe


The cargo area of commercial flights is at the same pressure as the cabin where you're riding. Usually pressurized to the equivalent of 8,000ft of altitude.


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## The Moontrane (Nov 28, 2005)

*A point of clarification*



JCavilia said:



> Think about it. Sea-level atmospheric pressure is about 15 psi. If your tires are inflated to 120 psi relative pressure at sea level, and you took them up to the space station and exposed them to near-vacuum, the relative pressure would rise to 135 psi. That would not be enough to blow the tires off.
> 
> Anyway, the cargo holds of airliners are pressurized just like the passenger compartment (the big aluminum cylinder of the fuselage is the pressure vessel -- it would be way more complicated and mechanically stressful to pressurize only part of it.) So the pressure change will only be like climbing to 8,000 feet or so, which is a drop of maybe 4 pounds.
> 
> ...


That would work if space were at 0 psi, but it's not; it’s at significant vacuum, well under 0 psi. Someone else can run the numbers, but trust me - your 120 psi tires would blow in space. 

That’s the biggest reason why I don’t ride in space. :wink:


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## Retro Grouch (Apr 30, 2002)

I've traveled by air with my bike tires fully inflated and also carried a couple of Co2 cartidges in the seat pack. It's a wonder that the plane didn't fall out of the sky


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## tom_h (May 6, 2008)

The Moontrane said:


> That would work if space were at 0 psi, but it's not; it’s at significant vacuum, well under 0 psi. Someone else can run the numbers, but trust me - your 120 psi tires would blow in space. ...


Not exactly -- sea level pressure is about 15 psia , ie pounds per square inch _absolute_. 
A vacuum is 0 psia. You can't get less than an "absence of all air". 

By convention, nearly all guages and tires use units of "psig" : pounds per square inch _guage._ 

"psig" adopts sea level pressure as being the "zero" of the scale. If measuring in psig, then yes, a vacuum would be negative (—) 14.7 psig.

But the choice of 'yard stick' won't affect the physical reality -- most tires won't explode if overinflated by 15 psi.


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## Kerry Irons (Feb 25, 2002)

*Joking, right?*



The Moontrane said:


> That would work if space were at 0 psi, but it's not; it’s at significant vacuum, well under 0 psi. Someone else can run the numbers, but trust me - your 120 psi tires would blow in space.


Do you really not understand this at all, or are you just joking?

As tom_h noted, full vacuum is -14.7 psig, so if the cargo hold was under full vacuum it would be the equivalent of adding 15 psi to your tire pressure, which would NOT blow your timres of the rim. And, as others have noted, the cargo hold is not under full vacuum, but rather at cabin pressure.


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## vetboy (Oct 11, 2005)

Retro Grouch said:


> I've traveled by air with my bike tires fully inflated and also carried a couple of Co2 cartidges in the seat pack. It's a wonder that the plane didn't fall out of the sky


Smart arse I'll be in your neck of the woods tomorrow. Just look for the untanned guy on the high end Look with blown out tires climbing Mt Fig.

Joe


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## Tugboat (Jul 17, 2006)

The Moontrane said:


> That would work if space were at 0 psi, but it's not; it’s at significant vacuum, well under 0 psi. Someone else can run the numbers, but trust me - your 120 psi tires would blow in space.
> 
> That’s the biggest reason why I don’t ride in space. :wink:


But zero rolling resistance... surely that's an incentive to ride in space!


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## Retro Grouch (Apr 30, 2002)

*Joe*

Where did you end up finding a place to stay during the ToC?



vetboy said:


> Smart arse I'll be in your neck of the woods tomorrow. Just look for the untanned guy on the high end Look with blown out tires climbing Mt Fig.
> 
> Joe


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## Camilo (Jun 23, 2007)

Like others have said, the cargo hold is the same pressure as the passenger compartment, ~8K feet elevation or so. It's just not practical to do so. In addition, I don't believe there's a huge difference in temperature. I've never had any thing get overly cold or frozen in my suitcase. I've never seen pressure or temperature as a caution for checking guitars and other instruments as baggage (the only danger that people report is careless baggage handling). Finally, I do not believe they have a special baggage compartment for pets. I doubt if they expose Fido to anything colder than a chilly day outdoors.


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## The Moontrane (Nov 28, 2005)

Kerry Irons said:


> Do you really not understand this at all, or are you just joking?
> 
> As tom_h noted, full vacuum is -14.7 psig, so if the cargo hold was under full vacuum it would be the equivalent of adding 15 psi to your tire pressure, which would NOT blow your timres of the rim. And, as others have noted, the cargo hold is not under full vacuum, but rather at cabin pressure.


Fo Shizzle Ma Nizzle! :biggrin5:


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## vetboy (Oct 11, 2005)

Retro Grouch said:


> Where did you end up finding a place to stay during the ToC?


I rented an RV and I'm staying in Beullton. I should be there by this evening (It's currently 5:20am in Toronto and I'm about the leave for the airport.

Joe


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## EDUC8-or (Jan 2, 2009)

Retro Grouch said:


> I've traveled by air with my bike tires fully inflated and also carried a couple of Co2 cartidges in the seat pack. It's a wonder that the plane didn't fall out of the sky


It would be extremely rare for one to explode, but if it did and was close to the fuselage it could create a hole and cause a rapid decompression or even cause a structural failure. I work for an airline and during our safety course we see what all kinds of items that seem harmless can do to an airplane, and it ain't pretty.


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## JustTooBig (Aug 11, 2005)

EDUC8-or said:


> It would be extremely rare for one to explode, but if it did and was close to the fuselage it could create a hole and cause a rapid decompression or even cause a structural failure. I work for an airline and during our safety course we see what all kinds of items that seem harmless can do to an airplane, and it ain't pretty.


The "What *CAN* Happen" scenarios sometimes border on Chicken-Little-like situations. In truth, there are already hundreds of CO2 cartridges on nearly every commercial aircraft in the sky -- wanna guess how the flotation devices get inflated?


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## Dumbod (Dec 31, 2004)

Tugboat said:


> But zero rolling resistance... surely that's an incentive to ride in space!


Screw rolling resistance.

No headwinds.


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## bwhite_4 (Aug 29, 2006)

This was a topic on VeloNews tech questions for Zinn.

Basically, airlines are stupid for not letting people take CO2 cartridges and you shouldn't need to let air out of your tires. The pressure in the airplane is far less than a hot car (hence the spontaneous combustible tire).


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## EDUC8-or (Jan 2, 2009)

JustTooBig said:


> The "What *CAN* Happen" scenarios sometimes border on Chicken-Little-like situations. In truth, there are already hundreds of CO2 cartridges on nearly every commercial aircraft in the sky -- wanna guess how the flotation devices get inflated?


There are airlines that will allow you to bring CO2 cartridges on board, mine will not. We don't use life preservers that inflate with CO2. There are things we carry that are lots worse than CO2 cartridges (oxygen generators and batteries come to mind) but I've just learned to follow the rules when I travel.


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## EDUC8-or (Jan 2, 2009)

I know yesterday we were at 39000' and our cabin altitude was about 5500'. We have the ability to heat the cargo areas, but usually just use a fan to circulate the air from the cabin to the cargo hold. If I had to guess I'd say it's very close to the same temperature as the cabin.


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## Dave Hickey (Jan 27, 2002)

Camilo said:


> Like others have said, the cargo hold is the same pressure as the passenger compartment, ~8K feet elevation or so. It's just not practical to do so. In addition, I don't believe there's a huge difference in temperature. I've never had any thing get overly cold or frozen in my suitcase. I've never seen pressure or temperature as a caution for checking guitars and other instruments as baggage (the only danger that people report is careless baggage handling). Finally, I do not believe they have a special baggage compartment for pets. I doubt if they expose Fido to anything colder than a chilly day outdoors.


Exactly. The cargo hold is kept at the same temperature and pressure as the cabin. No worries...


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## Kerry Irons (Feb 25, 2002)

*Is the sky falling?*



EDUC8-or said:


> It would be extremely rare for one to explode, but if it did and was close to the fuselage it could create a hole and cause a rapid decompression or even cause a structural failure. I work for an airline and during our safety course we see what all kinds of items that seem harmless can do to an airplane, and it ain't pretty.


I cannot imagine ANY possible circumstance where an "exploding" bicycle tire (in a box, bag, or even a plastic bag) could be in a position to mechanically damage any part of any airplane. The physical conditions, and the VERY imaginative scenario under which such damage could occur are just not in any way logical or feasible. I hope that your safety training has at least a slight grip on reality such that worries about things like this are not in the picture. If not, your airline has much bigger problems. Just saying.


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## Andrea138 (Mar 10, 2008)

They need to hire Kerry Irons to do the safety training. And probably to fly the planes, too.


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## EDUC8-or (Jan 2, 2009)

*The Sky Isn't Falling, You Just Didn't Read The Entire Post*



Kerry Irons said:


> I cannot imagine ANY possible circumstance where an "exploding" bicycle tire (in a box, bag, or even a plastic bag) could be in a position to mechanically damage any part of any airplane. The physical conditions, and the VERY imaginative scenario under which such damage could occur are just not in any way logical or feasible. I hope that your safety training has at least a slight grip on reality such that worries about things like this are not in the picture. If not, your airline has much bigger problems. Just saying.


During training we watched a video of a Hans and Frans with a gigantic bike tire that was inflated with a super-duper pump and they "Pumped It Up" so fast it blew like a top.  

Actually, I was talking about CO2 cartridges, not tires. I don't think they're dangerous since you pretty much need to whack them with a hammer or toss one in a fire to get it to explode, but crazier things have happened. Like I posted before, oxygen generators (transported improperly, but they're on just about every airliner) and laptop batteries (properly transported) have caused fires and brought down airplanes, one of them with fatal results.


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## Kerry Irons (Feb 25, 2002)

*Reading the post*



EDUC8-or said:


> Actually, I was talking about CO2 cartridges, not tires.


Yeah, but you didn't say that. The post you replied to mentioned tires first, then CO2. You didn't say which one you were talking about. Just saying.


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