When flying, deflate tires?

[mustang1]

I packed my bike up for its first flight and deflated the tires almost completely. I've read people deflate complete to others who don't deflate at all. How about you?

 

[Yellow Saddle]

I would love to know why airlines make you deflate the tyres. Can anyone shed light on this rule?

 

[byegad]

The theory from the airline's point of view is that in an unpressurised hold the drop in external air pressure will cause the tyre to blow. Given air pressure at sea level is 14psi or there abouts, if your tyre is inflated to the maximum allowed (sidewall) pressure less 14psi it will have no effect. In theory in a vacuum the internal pressure will have the same effect as full pressure at sea level. In reality the drop in temperature at altitude will mitigate the loss in external pressure anyway.

 

[screenman]

I would love to know why airlines make you deflate the tyres. Can anyone shed light on this rule?

They read about it on the net.

 

[screenman]

I think the idea might date back to when planes had outside toilets.

 

[Deleted member 23692]

I wonder if they deflate the undercarriage tyres too

 

[gavintc]

I think the idea might date back to when planes had outside toilets.

The ones on the wings were the most challenging. Thank goodness, they developed to the system described by Billy Connolly;

View: https://www.youtube.com/watch?v=CcOn5_SbCSA

 

[midliferider]

I did this first time I took the bike on the plane. Now I don't do it at all. They won't ask you any questions as long as you have paid the exorbitant fee that they charge.

 

[Lonestar]

I would love to know why airlines make you deflate the tyres. Can anyone shed light on this rule?

Air we go?

 

[screenman]

I did this first time I took the bike on the plane. Now I don't do it at all. They won't ask you any questions as long as you have paid the exorbitant fee that they charge.

Is it expensive to take a bike with you? I always thought it was good value.

 

[Yellow Saddle]

The theory from the airline's point of view is that in an unpressurised hold the drop in external air pressure will cause the tyre to blow. Given air pressure at sea level is 14psi or there abouts, if your tyre is inflated to the maximum allowed (sidewall) pressure less 14psi it will have no effect. In theory in a vacuum the internal pressure will have the same effect as full pressure at sea level. In reality the drop in temperature at altitude will mitigate the loss in external pressure anyway.

All the planes I've flow in other than my brother's Piper Cub, the hold is pressurized. My dogs can testify to that, as can the livestock frequently carried on airplanes. I've been on an Air Mauritius flight where the smell of goat was so strong nobody chose the meat options on the in-fight meal. I made up the bit about instant vegetarians, but you get the point. Even the air in the hold and cabin is all the same recycled air.

 

[Keith Oates]

The times I've flown with a bike the ground staff have always told me to deflate the tyres. If it is necessary or not never mind it's the airlines rules so conform to them. The same thing applies to switching off your mobile, if you are asked to do it then follow the request as it's not going to cost you anything.!!!!!!!!!!!!

 

[Yellow Saddle]

The times I've flown with a bike the ground staff have always told me to deflate the tyres. If it is necessary or not never mind it's the airlines rules so conform to them. The same thing applies to switching off your mobile, if you are asked to do it then follow the request as it's not going to cost you anything.!!!!!!!!!!!!

Yeah yeah, civil obedience and all that. I'd like to know why. Why can't I ask that question? I'm a naturally curious person.

 

[Mad Doug Biker]

I wonder if they deflate the undercarriage tyres too

That is exactly what I thought when I read this too!
I mean, the tyres have to be hard enough for the gear to take the strain when taking off/landing, so how would that work? Are they filled with something special stuff that doesn't expand? ....... Self deflating and inflating tyres? (A load of bull, I know)...... What?

 

[ufkacbln]

They used nitrogen gas in undercarriage tyres as the pressure effect is less than air.

The downside is that they do lose pressure quickly (something like 5% per day IIRC)

At least one air crash has been cause by these defective pressures or air being used instead of Nitrogen